In Far North, Peril and Promise
Great Forests Hold Fateful Role in Climate Change
By Doug Struck
Washington Post Foreign Service
Thursday, February 22, 2007; A01
PINE FALLS, Manitoba — Here on the edge of the silent and frozen northern tier of
the Earth, the fate of the world’s climate is buried beneath the snow and locked in
the still limbs of aspen trees.
Nearly half of the carbon that exists on land is contained in the sweeping boreal
forests, which gird the Earth in the northern reaches of Canada, Alaska, Scandinavia
and Russia. Scientists now fear that the steady rise in the temperature of the
atmosphere and the increasing human activity in those lands are releasing that
carbon, a process that could trigger a vicious cycle of even more warming.
The prospect of the land itself accelerating climate change staggers scientists, as
well as woodsmen such as Bob Austman, who stopped recently in a quiet stand of birch
on the edge of the boreal forest to examine a jack rabbit’s tracks.
“There are big forces out there,” he said succinctly.
Those forces, which scientists are only starting to understand, could free vast
stores of carbon and methane that have been collecting since the last ice age in the
frozen tundra and northern forests. Their release would push the world’s climate
toward a heat spiral that would raise ocean levels, spawn fierce storms and scorch
farmlands, scientists believe.
But the land is impartial. It could also be enlisted to help abate global warming,
as both a storehouse for man-made carbon dioxide and a natural sponge for greenhouse
gases. Policymakers are considering changes to protect and expand the forested areas
that store carbon; outside the boreal forest, they are experimenting with techniques
to bury man-made carbon dioxide in underground vaults and porous seams.
“The world is both victim of climate change and a possible solution to it,” said
Stewart Elgie, associate director of the Institute of the Environment at the
University of Ottawa.
Carbon is freed from the land in numerous ways. Permafrost melting because of warmer
weather exposes peat, deadwood and buried pine needles to decay, freeing the carbon
they contain. Fires, raging through forests more often because of hotter and drier
weather, send wood — and its carbon — up in smoke. Insects thriving in milder
winters girdle trees and send them to rot on the forest floor. Miners and oilmen
build roads that expose the earth and warm the land, and loggers cut down old
forests and replace them with young ones that will take decades of growth to absorb
and store the same amount of carbon.
As the released carbon rises, it adds to the belt of greenhouse gases in the
atmosphere, trapping even more heat, which causes more warming. Scientists call it a
“feedback loop.” Others have a more ominous term: the carbon time bomb.
Risk Poorly Understood
“We are taking risks with a system we don’t understand that is absolutely loaded
with carbon,” said Steven Kallick, a Seattle-based expert on the boreal forests for
the Pew Charitable Trusts. “The impact could be enormous.”
Scientists acknowledge they are not certain how the carbon time bomb will explode,
or when. Many of the consequences of global warming that experts once predicted
would take centuries are occurring in decades, such as the melting of the world’s
glaciers and ice caps. But other changes might be more gradual.
“With permafrost, it may take longer for change to get moving. But it may keep
moving, even if we get our emissions under control,” said Antoni Lewkowicz, a
professor of geography at the University of Ottawa. “It’s like a big boulder. Once
you get it moving, it won’t stop.”
Brian Amiro, head of the department of soil science at the University of Manitoba,
is part of a research team involved in a project called Fluxnet. The researchers
have erected more than 400 towers throughout the world, outfitted with instruments
to measure the exchange of carbon between earth and air. The boreal forest,
sometimes called “the lungs of the world, “breathes in more carbon in years when the
forests grow, and loses more carbon in years of bad forest fires, drought or insect
infestation.
Lately, there has been a string of bad years. The number of forest fires in Canada
doubled in the 1980s and ’90s from the previous two decades, and some scientific
models indicate they will double again this century, Amiro said. Logging, mining and
oil exploration have carved roads deeper into the forests. Temperatures have risen
faster toward the north — by as much as five degrees since the 1950s — than in
more temperate zones.
“The environmental triggers are going to become much more significant,” said Faisal
Moola, director of science at the David Suzuki Foundation, a Vancouver-based
environmental organization.
There are mixed views about whether the process can be stopped. The levels of carbon
dioxide in the atmosphere — the highest in at least 420,000 years–mean average
temperatures will continue to rise, accelerating the thawing.
But humanity’s footprint could be changed. Development, mining and logging account
for 25 percent of the carbon loss in forests, Elgie said. Logging releases almost
twice as much carbon dioxide each year as all the passenger vehicles in Canada, he
said.
Credits for Preservation
Here in Pine Falls, a town of 1,400 about 80 miles northeast of Winnipeg, the giant
Tembec pulp mill billows steam and smoke into the crystalline sky. The 1920s-era
mill makes newsprint from spruce and pine trees, and Vince Keenan, a forester for
the company, said Tembec has responded to calls for change. It has set aside 12
percent of its 2 million-acre logging forest here, and up to one-fourth of its
product is now made from recycled paper. Changes in mill practices have reduced
greenhouse gas emissions by nearly 50 percent since 1990, he said.
But a broader step would be to set aside vast areas of the forest now designated for
mining or logging and preserve them. This could be done by setting up a system of
“carbon credits,” in which, for example, an industrial plant would offset its
pollution by paying money to preserve land in the forest that could store an equal
amount of carbon.
“Right now, the only way to make money in the boreal forest is to cut trees down,”
Elgie said. “If you had carbon credits, you would be able to make money by keeping
the trees up and storing carbon.”
That system appeals to some native Indian groups, now torn between the desire to
keep their traditional lands and the need for income from logging or mining.
“Preserving the land is important to us,” said Carl Smith, an elder of the
Brokenhead Ojibway First Nation on the Winnipeg River near Pine Falls. “Once the
land is gone, you’re gone.”
Smith also is president of the Manitoba Model Forest, a group set up 15 years ago to
balance the competing views of how the forest here should be used. One of its goals
is teaching schoolchildren about the forest, a job that falls to Bob Austman, the
woodsman, whose family has lived in and on the boreal forests of Manitoba for three
generations.
He sees nothing but beauty here. As he and Brian Kotak, an environmental scientist,
tramped in minus-10-degree cold through a stand of birch near the Winnipeg River
recently, it seemed hard to see the Earth as a potential danger.
“The dilemma,” Austman said, “is that we live on a planet with 6 billion people.
This land is under increasing pressure.”
Turning a Minus Into a Plus
South of the great swath of forest in central Canada, the wrinkles of the land
smooth out, stretching toward a straight horizon. The Great Plains are frozen and
still in winter. But in Weyburn, 70 miles southeast of Saskatchewan’s capital,
Regina, pumps bob relentlessly amid the snowy wheat fields, sucking crude oil from a
mile underground like a host of mechanical mosquitoes.
What goes back into the ground here heartens some environmentalists. The giant
EnCana oil and gas company, which operates more than 700 oil pumps in this field,
pumps carbon dioxide deep down to drive more oil out of the porous rocks.
Almost inadvertently, the company has become the world’s largest working example of
carbon storage, or sequestration, a technique being hailed by international experts
as one tool to reduce greenhouse gases. Darcy Cretin, operations superintendent at
the EnCana plant, is slightly amused by the environmental scientists who have
flocked here to see the maze of pipes, pumps, valves and sensors planted in the
prairie.
“We have to keep explaining we are doing this to make more oil,” he said. “The
carbon sequestration is an extra.”
When the oil brought up at Weyburn dwindled after 40 years of pumping, EnCana struck
a deal with the Dakota Gasification Co. It owns a plant in Beulah, N.D., that
converts coal to natural gas. Combustion at the gasification plant makes carbon
dioxide, which was being vented into the air. EnCana offered to buy the gas, and in
1999 the U.S. company built a 200-mile pipeline into Canada. The foot-wide pipe
emerges from its underground route at a chain-link fence on the edge of EnCana’s
property.
The company pumps the carbon dioxide under high pressure into the oil field. The gas
acts as a kind of solvent, driving the oil out of porous rock. The greenhouse gas
remains underground, leaving buried nearly 5,000 tons a day that would otherwise
have gone into the atmosphere.
Experts believe this scheme of carbon storage could be used more widely in cases
where the gas could be easily collected at a single point and moved by pipeline to a
storage field. The approach would not work where the carbon dioxide could not be
collected easily, such as from the tailpipes of moving cars. But nearly 40 percent
of the carbon dioxide released to the air comes from big power plants or industrial
areas, where the gas could be captured.
A committee of more than 100 experts from the Intergovernmental Panel on Climate
Change concluded in 2005 that carbon sequestration has “considerable potential” to
help reduce greenhouse gases, and a lengthy study at Weyburn by the International
Energy Agency found virtually no leakage. The British Columbia government this month
announced that all its coal-fired electric plants will be required to utilize carbon
sequestration to eliminate greenhouse gas emissions.
For oilmen such as Cretin, the prospect of helping reduce a greenhouse gas by
pumping it underground seems a natural fit.
“This is pretty easy,” he said. “It’s basic stuff for us.”
Climate change could alter our landscape, including the very soil that we stand on
[New Hampshire] “Of all the things that have been looked at about the effects of
climate change, the effects in the soil is probably…the least well-studied.” Lack
of research means there’s still a lot of hypothesizing involved, but it seems likely
that one effect of global warming will be a loss of fertility in the soils of
forests and fields, root damage to trees and plants, and maybe even muddier mud
seasons. This has already proved a problem for the logging industry, which depends
on frozen ground to get its equipment into the woods in winter. This winter’s warm,
wet December and early January idled a huge number of loggers.
04040373/-1/news>
http://www.nashuatelegraph.com/apps/pbcs.dll/article?AID=/20070404/NEWS01/20
4040373/-1/news
The Australian — Breaking News
This story is from our news.com.au network Source: Reuters
Report warns of climate havoc
By Rob Taylor
March 30, 2007
AUSTRALIA, slowly emerging from its worst drought in a century, will suffer killer
heatwaves, bushfires and floods as global warming intensifies, a draft report by
international climate scientists said today.
Already the world’s driest inhabited continent, Australia’s outback interior will
see temperatures rise by up to 6.7C by 2080, the Intergovernmental Panel on Climate
Change (IPCC) report said.
“An increase in fire danger in Australia is likely to be associated with a reduced
interval between fires, increased fire intensity, a decrease in fire
extinguishments,” sections of the report leaked to Australian media said today.
The study will increase pressure on Australia’s conservative government, which
refuses to sign the Kyoto Protocol, to do more to combat climate change ahead of
elections later this year. Global warming is shaping as a major issue.
The draft is the second of four to be completed this year by IPCC climate experts
and will be released for discussion in Brussels on April 6.
The first study said there was almost 90 per cent certainty that humans were
changing the world’s climate and causing global warming, mostly through reliance on
burning fossil fuels.
The draft second report said sea levels would rise due to glacial melt, causing
havoc for coastal-dwelling Australia and New Zealand with “greater coastal
inundation, erosion, loss of wetlands and salt water intrusion into freshwater
sources”.
Rising temperatures would also hit the Great Barrier Reef with “catastrophic
mortality of coral species annually”.
The first report by the IPCC said the reef would be “functionally extinct” in 40 years.
Landslides, water shortages and storm surges would cause infrastructure destruction,
and heat-related deaths could rise to 6300 a year from 1115 at present by 2050, when
temperatures would have already spiked by 3.4C, the report said.
The Australian Government, which this week hardened opposition to signing the Kyoto
Protocol which set greenhouse gas reduction targets, said there was nothing new in
the draft.
“We know that there is the possibility or the probability of a hotter and drier
future,” Environment Minister Malcolm Turnbull said on ABC radio.
But former environment department chief Roger Beale, a member of the IPCC’s working
group on the economic impacts of climate change, said Canberra could not ignore the
findings.
“Australia among developed countries is very broadly exposed and we are already
close to the thresholds,” Mr Beale said.
Prime Minister John Howard this week rejected a plea from British climate economist
Nicholas Stern to urgently ratify the Kyoto Protocol and slash greenhouse gas
emissions by at least 60 per cent by 2050 to help fight global warming.
Mr Howard told Parliament that Sir Nicholas’s demands would destroy Australia’s
economic growth and cost jobs.
Environment group WWF said Australia faced massive upheaval and potentially waves of
wildlife extinctions due to global warming, with 1590 native species threatened.
“Even if major greenhouse emission reductions happened tomorrow, the climate will
still change dramatically and we have to be ready for it,” WWF spokesman Martin
Taylor said.
—
Warming climate creates mountains of mushrooms
http://environment.newscientist.com/article.ns?id=dn11549
CIENCEwww.sciencemag.org
VOL 315 16 MARCH 2007 1527
SPECIAL SECTION
Deep impact. Experts debate how well Arctic benthic communities will weather warming.
Thriving Arctic Bottom Dwellers Could Get Strangled by Warming
Ten years ago, biologists skirting Canada’s mainland Arctic coast on an
ice-breakerlowered a video camera to the bottom and got a surprise. Instead of the
desolation they expected below ice-covered waters, there was a crowd. Slender
brittle stars elbowed each other; fish glided by; anemones writhed under the
camera’s bright light. This wonderland could be jeopardized by climate change. “We
don’t know until it happens, but if you have no ice, you probably have no typical
Arctic fauna,” says Julian Gutt, a marine ecologist at the Alfred Wegener Institute
for Polar and Marine Research in Bremerhaven, Germany.
The Arctic bottom fauna, or benthos, is surprisingly rich in species, abundance, and
ecological significance. Of the northern ocean’s 5000 known marine invertebrates,
90% live on the bottom. In shallow waters, they form the basic diet of many topside
creatures including seabirds, walruses, bearded seals, and bowhead whales. Although
many of the tiny creatures are migrants from North Atlantic waters, up to 20% are
Arctic endemics.
The bounty exists because of the cold, not in spite of it. During the brief summer
warmth, ice algae and cold-water plankton explode into life. In warmer waters, such
simple organisms are devoured by zooplankton, which are devoured by predators, and
so on up the food
chain; thus nutrients stay in the water column. But in icy Arctic water, zooplankton
do not grow fast enough to consume the sudden rushes of plant life. As a result,
much of the plant life sinks to the bottom, where creatures there get it. For this
reason, the benthos “can have production that is actually greater than in the
tropics,” says Bodil Bluhm, a benthic ecologist at the University of Alaska,
Fairbanks (UAF).
Many biologists hypothesize that climate change could hurt the Arctic benthos and
the large creatures that live off it by wiping out ice (and hence ice algae),
lengthening growing seasons for zooplankton, and giving warm-water species a
foothold. “The way the system works now is very much in favor of the benthos,” says
UAF polar ecologist Rolf Gradinger. “If the system changes, things could go downhill
fast.”
A preview might come from the Bering Sea, between Russia and Alaska. There, higher
water temperatures and pullbacks in seasonal ice have progressed fast in recent
decades. Oxygen uptake in sediments (an indicator of carbon supply to living things)
has dropped by two-thirds, and populations of benthic creatures such as mussels have
declined by half. Diving ducks, walruses,and gray whales are moving away, while
pollock and other southern pelagic fish are streaming in
(Science, 10 March 2006, p. 1461).
Preliminary evidence suggests that higher temperatures may be starting to have
similar effects in the more northerly Barents and Laptev seas, off Scandinavia and
Siberia, says Dieter Piepenburg, a marine biologist at the University of Kiel in
Germany. Piepenburg, who wrote a 2005 review on Arctic benthos in Polar Biology,
says it remains to be seen whether this would spell the end. He says that Arctic
benthic organisms have probably already weathered not only warm cycles but also cold
ones so extreme that deep ice sheets repeatedly scoured bottoms clean of life far
out to sea. Piepenburg thinks the organisms may have migrated to deep waters and
then recolonized when the coast was clear.
Those deep waters may also contain more life than previously believed. In 2001, U.S.
researchers over the remote Gakkel spreading ridge detected chemical plumes
indicating hydrothermal vents — which feed biological hot spots in other parts of
the world — but were unable to locate a source. Indeed, no vents have yet been
found anywhere in the Arctic, but as part of the International Polar Year (IPY),
U.S. researchers in July will return to the Gakkeland deploy new under- ice
autonomous vehicles to hunt down and sample the chemical plumes. If they find vents
and vent creatures, the organisms may well be unique, because the narrow straits
connecting the Arctic to other oceans are too shallow to allow movement of deep-sea
creatures and thus mingling of genes.
Researchers are bound to discover many polar organisms, especially in deep places
like this, says Gradinger, who is leading the Arctic Ocean inventory for the
world-wide Census of Marine Life. The deep basins are mostly unexplored, he says,
and many small creatures that live buried in sediments even in shallow areas have
yet to be glimpsed. IPY may help change this; within its framework, Gradinger counts
20 biological collecting projects slated so far.
-K.K.
Published by AAAS
Google News Alert for: climate warming species
Butterflies in
Finland … to starfish in Monterey Bay
Earth & Sky – Austin,TX,USA
Seventy-four to 91% of species that have changed have done so in
accord with climate change predictions. We are seeing impacts of
current warming on every …
See all stories on this topic
—
SCIENCE NEWS
Vol. 171, No. 10
Week of March 10, 2007
Not-So-Perma Frost
Warming climate is taking its toll on subterranean ice
Sid Perkins
Daniel Fortier spends his summers studying the permafrost on Bylot Island, high in
the eastern Canadian Arctic. While hiking there early in the 1999 field season, he
distinctly heard the sound of running water yet saw no streams nearby. “I thought to
myself, ‘Where is this sound coming from?'” says Fortier. “So, like a good
researcher, I started to dig.”
Excavating the soil, known as permafrost because its temperature is below 0°C
year-round, Fortier tapped into a torrent-filled tunnel a meter or so below the
surface. By tracking the water course uphill, he found its source: Large volumes of
snowmelt had flowed into open fissures in the ground and had then melted a passage
through a network of subterranean ice wedges that had formed over millennia (SN:
5/17/03, p. 314: http://www.sciencenews.org/articles/20030517/bob10.asp).
Eventually, the surprising tunnel grew so wide that its roof caved in, creating a
gully that erosion then widened, says Fortier, a geomorphologist at the University
of Alaska in Fairbanks. By the end of the summer, that gully was about 250 m long
and 4 m wide. During the next 4 years, the network of underground tunnels at the
site turned into a 750-m-long system of gullies that drained an area about the size
of four soccer fields. Since then, Fortier and his colleagues have observed the same
phenomenon at other sites on Bylot Island.
Several teams of scientists had previously described similar networks of gullies at
various sites in the Arctic, but those highly eroded features had been deemed as
much as several thousand years old. “No one had ever seen one of these things
forming,” says Fortier. “We were in the right place at the right time.”
Researchers are observing many new phenomena in the Arctic-most of them related to
the world’s changing climate. Globally, 11 of the 12 years from 1995 to 2006 are
among the dozen warmest since the mid-1800s, scientists of the Intergovernmental
Panel on Climate Change reported last month. Average temperatures worldwide have
risen about 0.7°C in the past 100 years, but those in the Arctic have risen even
more. In high-latitude portions of Alaska and western Canada, average summer
temperatures have increased by about 1.4°C just since 1961 (SN: 11/12/05, p. 312:
Available to subscribers at http://www.sciencenews.org/articles/20051112/bob9.asp).
Those warmer air temperatures are significantly boosting soil temperatures in many
regions, new studies show. Because the average annual temperature at many Arctic
sites sits at or just below water’s freezing point, even a small increase in local
warming can have big consequences. Besides rendering underground ice wedges more
susceptible to melting, the hike in temperatures threatens near-surface permafrost
that has been in place since the height of the last ice age, about 25,000 years ago.
Ecological changes, such as shifts in the patterns and timing of forest fires,
further endanger near-surface permafrost. But researchers are still working out
whether the permafrost will disappear over decades or millennia.
Permafrost serves as a stable foundation for much of the Arctic’s infrastructure,
including pipelines, roads, buildings, and bridges. In many areas, that frozen
ground also contains huge amounts of organic material, which could readily decompose
and send carbon dioxide, a greenhouse gas, into the atmosphere if the permafrost
thaws (SN: 11/12/05, p. 312: Available to subscribers at
http://www.sciencenews.org/articles/20051112/bob9.asp).
Balancing act
When most people think of permafrost, they envision the coldest Arctic landscapes,
where layers of ground hundreds of meters thick have remained deep-frozen since the
last ice age, maybe even longer. However, permafrost need not be either long-lived
or icy. Geologists consider any soil or rock that’s been colder than 0°C for more
than 2 years to be permafrost.
Permafrost lies beneath as much as 25 percent of the land area of the Northern
Hemisphere. Although much of the frozen ground occurs in high-latitude regions, the
rocky summits of many high-altitude peaks in temperate and tropical latitudes also
consist of permafrost, says Margareta Johansson, a physical geographer at the Abisko
Scientific Research Station in Abisko, Sweden. She and her colleagues have conducted
long-term permafrost studies in the region surrounding Abisko, which is about 200
kilometers north of the Arctic Circle. They reviewed their findings in the June 2006
Ambio.
The presence or absence of permafrost at any particular spot depends on the balance
between geothermal heat making its way up from Earth’s interior and the average
annual air temperature at the site, says Johansson. “The lower a site’s average air
temperature is, the more heat the air pulls from the ground,” she notes, leaving the
soil colder and the permafrost thicker.
The slope of the terrain has a significant effect as well. South-facing slopes
usually receive more direct sunlight and therefore are warmer than flat terrain
would be. By contrast, northern slopes spend much of the day in shade, so soil
temperatures there are chillier than the region’s average and more conducive to the
formation of permafrost.
Although permafrost can form in any climate where the average annual air temperature
is below freezing, it doesn’t normally occur or persist widely until temperatures
are substantially lower, says Johansson. When an area’s average temperature lies
between 0°C and -1.5°C, permafrost is patchy and typically underlies no more than 10
percent of the region. At sites with average air temperatures below -6°C, few spots
if any are free of permafrost.
“The amount of snowfall at a site significantly affects the permafrost there, but in
a counterintuitive way,” says Johansson. When snow forms a thick blanket that lasts
all winter, it insulates the ground from the most frigid air of the year. Near
Abisko, which receives only about 30 centimeters of snow each year, the permafrost
is about 16 meters thick, the deepest in the region, she notes. At similarly cold
sites that receive as little as 1 m of snowfall each winter, permafrost is patchier
and only a few meters thick.
In experiments at several sites in the Abisko region, Johansson and her colleagues
piled up extra snow at some sites, artificially doubling or tripling the snowfall
that the spot would normally receive over a winter. As a result, average ground
temperatures rose as much as 2.2°C. That large a change can melt underlying
permafrost.
Scientists elsewhere have noted that winter snow cover can keep the average ground
temperature as much as 10°C higher than the average air temperature, Johansson
notes.
It’s often difficult for scientists to accurately predict how vegetation will affect
ground temperatures, says Johansson. Evergreen trees and shrubs cast shadows that
cool the ground during the summer. However, the vegetation forms a windbreak that
tends to trap snow in winter, creating drifts that warm the soil. Computer
simulations suggest that shrubby sites in northern Alaska accumulate as much as 20
percent more snow than bare ones do, and scientists have found that the soil in
shrubby areas is about 2°C warmer than soil in shrub free spots nearby.
Fire and ice
The wildfires that intermittently ravage Arctic forests can exact a harsh toll from
permafrost. It’s not the heat of the conflagration that does the damage but the
changes that take place after the fire dies down.
TOP VIEW. Permafrost, depicted in various shades of purple, underlies about
one-fourth of the Northern Hemisphere’s land area. The darker the purple, the
greater the percentage of local landscape that permafrost underlies. Intl.
Permafrost Assn. and P. Rekacewicz/UNEP/GRID-Arendal
A severe fire strips away the foliage that shades the forest floor. The resulting
increase in sunlight reaching the ground boosts soil temperature, says Eric S.
Kasischke, a fire ecologist at the University of Maryland, College Park.
An even greater warming effect stems from the fire’s consumption of the limbs,
twigs, needles, and leaves that had fallen to the ground and insulated it. Unlike a
blanket of snow, forest litter insulates the ground year-round. It keeps the ground
warmer in winter and cooler in summer. On balance, the insulation favors permafrost
formation and retention.
Consider what happens in a black spruce forest, the type that makes up more than
half of North America’s boreal forests. Scientists have gathered data at more than
200 central-Alaska sites that had recently suffered wildfires. On average, between
50 and 60 percent of the forest-floor litter goes up in smoke during a fire,
Kasischke and his colleagues reported at a meeting of the American Geophysical Union
in San Francisco last December.
After a fire has destroyed so much litter, a much thicker surface layer of soil
thaws each summer, says Kasischke. During the growing season, seedlings quickly
become established in that thawed soil. Then, as trees mature, they shade the ground
more effectively and drop limbs and needles to reestablish the forest floor’s veneer
of insulation.
Computer models suggest that permafrost begins to recover when organic material on
the forest floor accumulates to a depth of at least 9 cm. In a region where trees
grow slowly, that could take decades.
The interval between wildfires in any particular patch of boreal forest ranges
between 30 and 300 years, Kasischke notes. But, the postfire recuperation of a
forest’s permafrost isn’t a sure bet. Because today’s climate in a region may be
substantially warmer than it was the last time fire swept through, conditions may
not be conducive to permafrost recovery.
Hanging on
When the centuries-long cold spell called the Little Ice Age ended about 150 years
ago, glaciers and permafrost reached their maximum extent of the past few millennia.
Deep remnants of that permafrost will probably persist for millennia to come.
However, in a world that’s warming, it’s only a matter of time until much of that
ice melts. Most permafrost loss will take place at shallow depths, where it will
have the greatest effect on ecosystems and people.
In many regions, permafrost temperatures, like air temperatures, have been climbing
steadily for decades, says Sergei Marchenko, a permafrost researcher at the
University of Alaska in Fairbanks. Data gathered in field studies since the early
1970s indicate that permafrost temperatures in the Altai region of Mongolia and the
Tian Shan mountains of central Asia have risen as much as 0.2°C per decade, he
notes. Similar rates of warming have been observed on the Tibetan Plateau since
1985.
In the Tian Shan mountains, the thickness of the seasonally thawed layer has
increased 23 percent since the early 1970s. It’s now 5 m thick, says Marchenko.
Climate simulations suggest that since the end
of the Little Ice Age, the lowest altitude at which permafrost could persist has
climbed about 200 m. During that time, about 16 percent of the region’s permafrost
would have disappeared, according to the model that Marchenko and his University of
Alaska colleague Vladimir Romanovsky described at the American Geophysical Union
meeting.
Measurements taken inside three boreholes, each at least 400 m deep, at a mine in
the barren terrain of northern Quebec also chronicle modern-day warming, says
Christian Chouinard, a paleoclimatologist at McGill University in Montreal. The data
suggest that surface soil has heated up about 2.75°C in the past 150 years, he and
his colleagues reported at the meeting.
A slight cooling trend in the region from the 1940s to the early 1990s has since
been replaced by extremely rapid warming-more than 1°C in the past 15 years or so,
the researchers note.
Permafrost can be quick to warm to its melting point but then slow to melt. The
energy needed to melt a block of ice at 0°C is about 80 times the amount that’s
needed to raise its temperature from -1°C to 0°C, says Sharon L. Smith, a permafrost
researcher at the Geological Survey of Canada in Ottawa.
Data gathered throughout Canada show that permafrost in the coldest regions of the
country is steadily warming, as are soils in areas free of permafrost. However, in
the areas where permafrost sits at its melting point, ground temperatures aren’t
changing significantly. Much of the air’s thermal energy goes into melting the
permafrost rather than into warming it.
About 42 percent of Canada’s land area, or about 4 million square kilometers,
overlies permafrost, says Smith. In about half that area, the permafrost is patchy
and thin, with a temperature above -2°C. If many scientists’ climate-warming
scenarios come to pass, Smith says, “permafrost in those regions could ultimately
disappear.”
When it will disappear is another issue. Research published in 2005 sparked a major
debate. In that report, climate scientists David M. Lawrence of the National Center
for Atmospheric Research in Boulder, Colo., and Andrew G. Slater of the University
of Colorado at Boulder suggested that climate warming will wipe out more than 90
percent of the world’s near-surface permafrost by the year 2100.
That dramatic claim is almost certainly wrong, says Christopher Burn, a permafrost
researcher at Carleton University in Ottawa. Burn says that although he doesn’t
dispute the predictions of climate warming, he does question Lawrence and Slater’s
predictions concerning the pace and extent of the permafrost’s demise.
Burn says that the Colorado scientists’ estimate requires that permafrost melt
almost instantaneously. Instead, the time lag between the climate warming and the
permafrost melting will probably be hundreds of years, he suggests.
Lawrence agrees that the computer model that he and Slater used for their study had
some limitations-for instance, it included only the top 3.4 m of the ground and
didn’t account for conditions associated with some soil types. The pair has now
modified its model to look 50 m into the ground, says Lawrence. Preliminary results
suggest that this deeper permafrost will indeed last longer than they’d previously
predicted – but only a couple of decades longer at most – he reports.
Nevertheless, Burn says that the model doesn’t take into account the cooling effect
of permafrost that lies deeper. For example, permafrost in Alaska and western Canada
extends as much as 600 m into the ground, and in Siberia it’s more than 1.5 km
thick. “The persistence of permafrost increases with its thickness,” Burn adds. So,
deep soil will stay cold for millennia, thereby putting brakes on the warming of the
higher layers.
Whatever the rate of permafrost loss, Earth’s rapidly warming climate will continue
to gnaw at the long-frozen soil that serves as the bedrock of the Arctic. The carbon
dioxide that will probably be released in the process will only tend to accelerate
the permafrost’s disappearance.
————————————————————————
To sign up for the free weekly e-LETTER from Science News, go to
http://www.sciencenews.org/pages/subscribe_form.asp.
References:
Alley, R., et al. 2007. Climate Change 2007: The Physical Science Basis: Summary for
Policymakers. Intergovernmental Panel on Climate Change. Feb. 2. Full text available
at http://www.ipcc.ch/SPM2feb07.pdf. (Information regarding past and future IPCC
reports can be found at http://www.ipcc.ch).
Burn, C.R., and F.E. Nelson. 2006. Comment on “A projection of severe near-surface
permafrost degradation during the 21st century” by David M. Lawrence and Andrew G.
Slater. Geophysical Research Letters 33(Nov. 16):L21503. Abstract available at
http://dx.doi.org/10.1029/2006GL027077.
Chouinard, C., R. Fortier, and J. Mareschal. 2006. Ground surface temperature
history inferred from a borehole temperature profile through the permafrost in
northern Quebec: Evidence for recent warming (Presentation C51B-0420). American
Geophysical Union meeting. Dec. 11-15. San Francisco. Abstract.
Fortier, D., Y. Shur, and M. Allard. 2006. Role of underground erosion of ice wedges
in drainage system formation (Presentation C51B-0408). American Geophysical Union
meeting. Dec. 11-15. San Francisco. Abstract.
Johansson, M., et al. 2006. What determines the current presence or absence of
permafrost in the Tornetrí¤sk region, a sub-arctic landscape in Northern Sweden?
Ambio 35(June):190-197. Abstract.
Kasischke, E.S., et al. 2006. Consumption of surface organic layer carbon during
fires in Alaskan black spruce forests (Presentation B43B-0268). American Geophysical
Union meeting. Dec. 11-15. San Francisco. Abstract.
Lawrence, D.M., and A.G. Slater. 2005. A projection of severe near-surface
permafrost degradation during the 21st century. Geophysical Research Letters 32(Dec.
28):L24401. Abstract available at http://dx.doi.org/10.1029/2005GL025080.
Marchenko, S., and V. Romanovsky. 2006. Temporal and spatial changes of permafrost
in the Tien Shan Mountains since the Little Ice Age (Presentation C51B-0426).
American Geophysical Union meeting. Dec. 11-15. San Francisco. Abstract.
Smith, S.L., and M.M. Burgess. 2004. Sensitivity of permafrost to climate warming in
Canada. Bulletin 579. Geological Survey of Canada. Ottawa.
Further Readings:
Perkins, S. 2007. From bad to worse: Earth’s warming to accelerate. Science News
171(Feb. 10):83. Available to subscribers at
http://www.sciencenews.org/articles/20070210/fob1.asp.
______. 2005. Runaway heat? Science News 168(Nov. 12):312-314.
Available to subscribers at
http://www.sciencenews.org/articles/20051112/bob9.asp.
______. 2003. Patterns from nowhere. Science News 163(May
17):314-316.Available at
http://www.sciencenews.org/articles/20030517/bob10.asp.
Sources:
Christopher R. Burn
Department of Geography and Environmental Studies
Loeb Bldg., #A330
Carleton University
Ottawa, Ontario, K1S 5B6
Canada
Christian Chouinard
University of Quebec
GEOTOP-UQAM
McGill University
P.O. Box 8888
Station “Downtown”
Montreal, QC H3C 3P8
Canada
Daniel Fortier
Institute of Northern Engineering
University of Alaska, Fairbanks
College of Engineering and Mines
P.O. Box 755900
Fairbanks, AK 99775-5900
Margareta Johansson
Abisko Scientific Research Station
SE-981 07 Abisko
Sweden
Eric S. Kasischke
Department of Geography
University of Maryland, College Park
2181 LeFrak Hall
College Park, MD 20742
David M. Lawrence
Climate and Global Dynamics Division
National Center for Atmospheric Research
P.O. Box 3000
Boulder, CO 80307
Sergei Marchenko
University of Alaska, Fairbanks
903 Kuyukuk Drive
Fairbanks, AK 99775-7320
Sharon L. Smith
Natural Resources Canada
601 Booth Street, 1st Floor, Room. 189
Ottawa, ON K1A 0E8
Canada
Copyright (c) 2007 Science Service. All rights reserved.
—
Deforestation Main Challenge for UNEP
[Kenya] The severe degradation of the environment and its impact on climate change
are dominating discussions currently underway at the 24th meeting of the governing
council of the United Nations Environment Programme (UNEP) in the Kenyan capital.
Delegates at the five-day meeting are in agreement that climate change, which
remains the world’s overriding environmental challenge, requires global efforts to
counter it. Reducing deforestation is being cited as a key measure to mitigate some
of the effects of climate change. Still the climate change discussions also include
concerns that another solution involves the reduction of greenhouse gas emissions
(GHG) by industrialised countries.
http://www.ipsnews.
net/news.asp?idnews=36484
Restoration Ecology
Vol. 14, No. 2, pp. 170-176 JUNE 2006
Ecological Restoration and Global Climate Change
James A. Harris, Richard J. Hobbs, Eric Higgs,and James Aronson
***(NOTE: what follows is an extended excerpt only. If you’d like to
see the full article, as a pdf file, send request to
lance@wildrockies.org)***
Abstract
There is an increasing consensus that global climate change occurs and that
potential changes in climate are likely to have important regional consequences for
biota and ecosystems. Ecological restoration, including (re)-afforestation and
rehabilitation of degraded land, is included in the array of potential human
responses to climate change. However, the implications of climate change for the
broader practice of ecological restoration must be considered. In particular, the
usefulness of historical ecosystem conditions as targets and references must be set
against the likelihood that restoring these historic ecosystems is unlikely to be
easy, or even possible, in the changed biophysical conditions of the future. We
suggest that more consideration and debate needs to be directed at the implications
of climate change for restoration practice.
Key words: climate change, ecosystem change, ecosystem function, historical
ecosystem, restoration goals.
Introduction
In this paper, we examine the likely implications of global climate change for
ecological restoration. Ecological restoration, particularly in terms of
(re)afforestation and restoration of degraded agricultural land, is often seen as
one of the important responses to climate change because such activities help
influence the planet’s carbon budget in a positive way (e.g., Watson et al. 2000;
Munasinghe & Swart 2005). However, climate change also has the potential to
significantly influence the practice and outcomes of ecological restoration carried
out for other purposes because of the changed biophysical settings that will be
prevalent in the future.
The practice of ecological restoration, and the science of restoration ecology, has
developed rapidly over the past few decades to the extent that a cohesive body of
theory is beginning to emerge that is linked to increasingly sophisticated
restoration practices (e.g., Higgs 2003; van Andel & Aronson 2006; Falk et al.
2006). However, we need to ensure that the theory, and the practice, fit with the
realities of our ”brave new world,” also known as our ”planet in peril,” where
rapidly changing environmental and socio-economic conditions seem to be spinning
entirely out of control, or at least out of all historical ranges of variability.
Set against this is a tendency in much restoration practice, and indeed in much of
the theoretical discussion on restoration, to respect historical conditions either
as the basis for explicit objectives or to reset ecological processes to defined
predisturbance conditions (e.g., White & Walker 1997; Swetnam et al. 1999; Egan &
Howell 2001). Here we discuss the potential impacts of climate change on our ability
to achieve such a goal and then suggest possible ways forward in framing meaningful
and realistic restoration objectives for the future.
Climate Change Impacts
It is increasingly likely that the next century will be characterized by shifts in
global weather patterns and climate regimes, according to current climate
predictions (Watson et al. 2001; McCarthy et al. 2001; Munasinghe & Swart 2005). The
predictions, although containing wide latitudes of potential outcome, are all
pointing the same way:
d Changes in weather patterns
d Increases in mean temperatures
d Changes in patterns of precipitation
d Increasing incidence of extreme climatic events
d Increasing sea level
These changes are likely to be sudden (in some cases over periods of 5 years) and
unpredictable as to timing and intensity. However, it is clear that even if
immediate, concerted, and decisive action is taken, dramatic and significant changes
are inevitable in the next 20-30 years. The ecological consequences of such changes
are increasingly discussed in the literature (e.g., Hulme 2005; King 2005). There is
mounting evidence that the impacts of climate change on plant and animal species and
ecosystems can already be detected (Parmesan & Yohe 2003; Root et al. 2003). Can
impact on the human species be any less?
Considerable uncertainty remains, however, concerning the direction and extent of
change on a regional basis, and this poses significant challenges for restoration
and ecosystem management in general. Indeed, such uncertainties can be seen as
obstacles that prevent decisions being made (e.g., Lavendel 2003), despite the fact
that it seems essential to incorporate serious consideration of expected future
environments into restoration planning and practice.
Even without the predicted changes in climate over 50 years, the direct impacts of
increasing CO2 concentrations in the atmosphere would themselves have important
implications for restoration practices. For instance, detailed studies of African
savanna dynamics by Bond & Midgley (2000) and Bond et al. (2003) indicate that the
balance between herbaceous and woody components of savannas is strongly linked to
atmospheric CO2 concentrations. This suggests that historical tree-grass proportions
are unlikely to be replicated under current or future elevated CO2 levels; hence,
the restoration of savanna ecosystems to a previous state may not be possible in the
future with reasonable effort. Concurrently, Bellamy et al. (2005) have demonstrated
severe and rapid loss of carbon from soils in the United Kingdom attributed to
climate change. This situation is likely to be ubiquitous in extra-tropical regions
globally.
Although future climate change scenarios vary in intensity of impact (Watson et al.
2001), they share some common features, such as change in mean annual temperatures
and changes in patterns of precipitation. In the southern United Kingdom, for
example, the lowest impact scenarios have annual changes of 1 2.5 C and between 10
and 20% less
precipitation, characterized by warmer, wetter winters and warmer, drier summers by
2080 (UKCIP 2005). Recent work to map changes in biophysical regime in the U.S.A.
found that half of the area would have shifts in moisture, temperature, and soil
conditions unable to sustain”historic” ecosystems in those areas, that is, those
likely to be present pre-settlement (Saxon et al. 2005).
More substantial change is anticipated for high northern latitudes, and evidence of
significant change is already being detected (ACIA 2004). Within the next 100 years,
and much sooner in some regions, prescribing restorations using purely historical
references will prove increasingly challenging at best and at worst lead to failure.
Ecological restoration programs have a timescale of at least this long, particularly
when considering wooded ecosystems and reestablishment of complex food chains. For
example, there is much focus on conservation of ”ancient” woodlands in the United
Kingdom, ancient woodland being defined as ”land believed to have been continuously
wooded since at least 1600 AD” (Spencer and Kirby 1992).
This leads to the question ”how appropriate are historical ecosystem types when
faced with rapidly changing biophysical conditions?” Is it appropriate to consider
a temperate woodland restoration endpoint in an area likely to be flooded by rising
sea level? Why establish wetland in an area likely to become semiarid?
As much as rapid climate change makes for difficult scientific and technical issues,
there are vexing moral questions, too, that make our thinking and action even more
complicated. Threatened species and ecosystems will be increasingly hard to predict,
and their recovery more difficult, sometimes practically impossible, to achieve.
Whatever means develop for restoring rapidly shifting ecosystems, the translocation
of species is a likely technique. This bears the burden of breaking our relations
with particular places and upsetting long-duration place-specific evolutionary
processes.
There is the hazard of becoming more comfortable with serving as active agents in
ecosystems to the extent where historical fidelity is almost entirely abandoned. It
is one matter to watch change happen in ecosystems and wonder how and how much to
intervene, and quite another to become a determining agent in that change. How smart
can we be, and how much hubris is there in presuming that we can understand and
predict ecological change?
Finally, and this is by no means an exhaustive list of moral concerns, there are
consequences for the vitality of restoration as a practice in a broader public
giving up critical support for ecological integrity when ecosystems are changing
rapidly. Why, after all, support the finely honed techniques and ambitions of
restoration when mere ecological productivity appears adequate?
Static Conservation and Restoration Objectives
The predicted climate change scenarios will thus be particularly challenging in the
context of national legislative frameworks designed to protect habitat types and
important species. In the United Kingdom, for example, the designation of Sites of
Special Scientific Interest for wildlife protection is made on the basis of the
presence of particular named species being present on those sites (Department for
Environment, Food and Rural Affairs 2003). Similarly, in Canada, recent legislation
to protect species at risk focuses primary attention on species instead of
ecosystems at risk, which binds recovery and restoration efforts to targets that may
become increasingly difficult and expensive to reach. As the biophysical envelope
changes geographically, these sites will no longer support many of the species used
in the notification and designation process, which must then bring their special
status into question.
How then are these species to be protected? Active ecological restoration of
appropriate sites in new locations would appear to be one answer. Conservation
schemes tying assemblages to one place may actually lead to ossification of those
ecosystems – in effect making them more fragile and less resilient by not providing
space for the elements of the total gene pool on the fringes of the bell-curve niche
space for occasional regeneration, and thereby reducing or eliminating the ability
of the species and ecosystem to adapt to changes in biophysical regime. In a
constant environment, for example, one forced by ”conservative” conservation
practices, an ”optimum” phenotype is selected for, and extremes selected against.
Individuals that vary from this mean are eliminated, reducing the potential for
adaptation to a rapidly shifting biophysical regime, as may occur under certain
climate change scenarios (Rice & Emery 2003).
Genetically Engineered Trees: No Solution to Global Warming
http://globaljusticeecology.org/index.php?name=getrees&ID=380
UN COP-8 Briefing No. 2: GE
Trees/Global Warming
Briefing issued by EcoNexus and Global Justice Ecology Project
Genetically Engineered Trees: No Solution to Global Warming
UN COP-8 Briefing No. 2
As they grow trees naturally take in carbon from the atmosphere and store it in
their tissue. This ability to “sequester” carbon is now being considered as a means
to “offset” the C02 emissions from polluting industries to combat global warming.
Industry claims the development of monoculture tree plantations will absorb carbon
at a faster rate than natural forests and are now looking to fast-growing GE trees
as the latest solution. These claims, however, are unsubstantiated. Research
actually shows:
* Native forests overall absorb more carbon than plantations;
* Plantations bring many additional problems, including water and nutrient
depletion, increased soil salinity and acidity, increased fire risk and biodiversity
loss;
* GE trees (e.g. Bt and reduced lignin trees) may exacerbate these problems and will
cause novel ones, including alteration of decomposition, insect and disease
patterns.
In Brazil, pulp and paper giant Suzano, which manages over 3,000 square kilometers
of land in Brazil, is working with the Israel-based biotechnology firm “CBD
Technologies,” which claims to have identified a gene, called Cellulose Binding
Domain (CBD), which accelerates the growth of trees, increasing their carbon
sequestration. CBD Technologies Chief Executive Officer (CEO) Seymour Hirsch states,
“A one hectare forest consumes 10 tons of carbon annually from the C02 that the
trees breathe. Clearly a forest that grows twice as fast consumes twice as muchÃ…Â “1
The established myth that forests drastically slow or even stop their carbon
sequestration as they mature has been found to be false. Research shows that intact
mature forest ecosystems have a net carbon absorption not directly related to the
growth of the established forest trees. Undergrowth and natural regeneration
additionally contribute to carbon absorption. Forest soils also hold carbon, which
is lost into the atmosphere when the forest is logged.
A 1995 report by the World Resources Institute and the US Environmental Protection
Agency found that plantations and tree farms in tropical forests at best only store
25% of the carbon absorbed by native forests.2
Replacing native forests with plantations does not only remove the carbon stored in
the forest and release it into the atmosphere, but will also decrease the overall
carbon absorption rate, thus exacerbating global warming rather than mitigating it.
The use of genetically engineered trees as a techno-fix solution to global warming
poses a further threat to native forests and their capacity to help balance the
global climate.
Fast-growing GE tree plantations maturing in as few as three years are likely to be
given higher priority than slower-growing traditional tree plantations. This may
explain why corporations such as Royal Dutch Shell have been involved in the genetic
engineering of trees.3
However, a recent study funded by Duke University’s Center on Global Change, the
National Science Foundation, the National Institute for Global Environmental
Change/Department of Energy, the inter-American Institute for Global Change
Research, and others has found that “Growing tree plantations to remove carbon
dioxide from the atmosphere to mitigate global warmingÃ…Â could trigger environmental
changes that outweigh some of the benefits.”
These effects include water and nutrient depletion and increased soil salinity and
acidity, said the researchers. “Almost all plantation trees are heavy water using
evergreen species such as pines and eucalyptus,” said Robert Jackson, a professor in
Duke University’s Department of Biology and Nicholas School of the Environment and
Earth Sciences. The report continued, “Together with nutrient removal, leaf and
needle fall from plantation trees can also acidify soils.”4
Two of the trees receiving the most attention from genetic engineers are eucalyptus
and pine. Expanding plantations of faster growing and low-lignin eucalyptus and Bt
pines will exacerbate the problems detailed by the Duke University study.
Additional problems with GM trees include: selection pressures for
pesticide-resistant insects and disruption of forest ecosystems for which insects
are an integral component; damage to soils; lignin-reduction resulting in trees
which more easily decompose, thus releasing carbon; and manipulation of
disease-resistance causing the creation of increasingly pathogenic viruses.5 These
and other problems inherent with genetically engineered trees will lead to forest
health crises that worsen global warming rather than mitigate it.
Global warming itself could determine the effectiveness of the carbon offset
plantation model. The carbon sink method could turn out to be a double-edged sword.
Plantations have been found to be at high risk of catching fire. In a world of
rapidly increasing temperatures and unpredictable weather, many of the proposed
carbon sinks could actually worsen the situation. The Indonesian forest fires of
1997, for example, produced more carbon emissions than did all of the European Union
countries together that year.6
The Canadian International Development Agency (CIDA) Forestry Advisors Network
estimates that in 1950 there were 2.5 billion hectares of tropical forest. By 2000
they estimated that only 2.0 billion remained-a loss of 20%.7
To return to the carbon sequestering potential of 1950 would require the
re-establishment of 500 million hectares of native forest. It is unlikely that the
carbon sink values of these vanished forest ecosystems can be replaced by
plantations, however large.
The United Nations’ Inter-governmental Panel on Climate Change authored a report in
February 2001 that supported the idea of carbon offset forestry, but admitted the
carbon storage effects would be temporary.
Industry and Northern countries are promoting the idea that it is cheaper to
establish plantations on cheap land (in the Global South), than to reduce pollution.
In order to ensure “net carbon gain”, these lands have to be protected from
activities that would compromise their carbon sequestering ability. Thus, resident
communities are being displaced until the plantations are mature enough to be
logged, even though logging largely defeats the goal of sequestering carbon.8
In Ecuador, for example, companies are signing contracts with local and indigenous
communities to lease their land for 25-99 years, paying the communities US$19 per
hectare per year to tend the plantations. If something happens to the plantations
that reduces their carbon sequestration levels (such as a fire), the communities
will incur substantial debt.
In addition, preservation of forested areas or establishment of plantations
displaces local forestry activities (pushing logging or agricultural conversion to
other areas)-so defeating the objective of increasing the carbon stored.9
Other measures that have to be taken to ensure an overall increase in carbon
absorption include:
* fire suppression to avoid loss of carbon;
* stopping decay or disease in trees;
* assurances that funding would not be lost for other forest protection programs;
* ensuring that the promotion of carbon plantations does not slow or prevent the
development of technologies for carbon emission reduction;
* forests outside of project boundaries may experience greater threat, for, as the
Carbon Storage Trust suggests, “carbon credits for forest protection could become
the greatest incentive for deforestation ever conceived.”;10
* guarantees that carbon credit forestry wouldn’t drive up wood/timber prices-a side
effect that would result in greater incentives to log elsewhere.11,12
As The Corner House and EcoNexus further explain,
“the effect of plantations on erosion and carbon storage of soils downstream would
have to be calculated for a century or more. Ways would also have to be found to
anticipate and account for possible loss of trees from insect infestation, disease
or accident. For carbon credits to have even nominal validity, these predictions
would have to be made to be as certain as the prediction that, when fossil fuels are
burned, carbon dioxide will be produced. This is a tall order given that even today
it remains unclear where all the world’s carbon sinks are, how their CO2-fixing
capacity works or will be affected by
hotter temperatures, and so on…”13
In conclusion, carbon offset forestry is designed to allow the Industrialized North
to maintain their massively consumptive lifestyle
at the expense of the Global South by expanding tree plantations. Genetically
engineered trees are not a solution to global warming. If
plantations of GE trees spread further into native forests, or if their genetic
material contaminates native forests, then genetically engineered trees could lead
to accelerated global warming and the continued devastation of the earth’s
biological diversity.
Genetically engineered trees do not offer a solution to global warming, rather they
are a global distraction from finding real solutions to the problems of global
warming. In addition, they threaten the world’s forests through gene flow and other
hazards. This is why people on all continents are raising the call for a global
moratorium on the release of genetically modified trees into the environment.
Endnotes
1. Dar, Z. “CBD’s ‘Giving Tree'”
cfyn.ifas.ufl.edu/cbd.pdf
2. Trexler, M.C., Haugen, C., “Keeping it Green: Tropical Forestry
Opportunities for Mitigating Climate Change,” World Resources
Institute, EPA, March, 1995.;
3. Langelle, Orin, “From Native Forest to Frankenforest,” in Brian
Tokar, ed., Redesigning Life, The Worldwide Challenge to Genetic
Engineering, London: Zed Books, 2001, p. 122
4. Public release, 22/12/05, Duke University.
http://eurekalert.org/pub_releases/2005-12/du-sct121905.php
5. Sampson, V., Lohmann, L., “Genetically Modified Trees,” Corner
House & EcoNexus Briefing No. 21, December, 2000, p. 8.
6. “Getting to the Root of Sinks,” REC: The Bulletin 8/3, 7/28/99,
www.rec.org
7. “Decline of Tropical Forests,” Global Futures Bulletin #83,
Institute for Global Futures Research.
8. Kronick, C., “The International Politics of Climate Change, The
Ecologist, Vol. 29, No. 10, p. 105; also “Carbon ‘Offset’
Forestry & Privatization of the Atmosphere,” Corner House &
EcoNexus Briefing No. 15, July 1999, p. 5-6
9. Carbon Storage Trust, “Carbon Offsets in Forestry,” Oxford,
1999 p. 12; Smith, J., Mulongoy, K., Persson, R. and Sayer, J.,
“Harnessing Carbon Markets for Tropical Forest Conservation: Towards a
More Realistic Assessment,” Center for International Forestry
Research, Jakarta, 1998, p. 8
10. Carbon Storage Trust, op. cit. 17, p. 8
11. Smith, J. et. al., op. cit. 17 p. 8.
12. Corner House & EcoNexus, op. cit. 7, pp. 8-10
13. Corner House & EcoNexus, op. cit. 7, p. 9.
The Congressional Research Service (CRS) provides analyses for use by the U.S.
Congress. On February 6, 2007, CRS released its review of the science on climate
impact on wild species in America. The to-the-point, 6-page review also cites policy
issues expected to arise as climate pressures mount. These policy issues include
adequacy of current plans–e.g., land management plans–to protect species now
listed as threatened or endangered.
Click to access RS22597_20070206.pdf
Warming, Snowcover, Monsoons, & Marine Life
http://earthobservatory.nasa.gov/Study/Monsoon/printall.php>http://earthobservatory.nasa.gov/Study/Monsoon/printall.php
Book Review
http://www.uidaho.edu/e-journal/ecoforestry/ije124rev.html
In his book, “The Dying of the Trees,” Charles Little presents details of a pandemic
of sick and dying trees all over North America. This book focuses on a topic often
ignored in forestry : Death. Death is usually not addressed in literature or
research, other than as a limit or a temporary medical shortcoming. In fact, a
forest is as much dead as it is alive; there is a rhythm of death and replacement
from the cellular to the ecosystem level.
Trees in a forest are always dying, either individually or in groups, waves,
cohorts, or systems. Forests also may die, if enough of the trees die, as a result
of catastrophic change or of too rapid or too much change. Mortality is a normal
part of the life cycle. Mortality in forests usually occurs from a combination of
factors. Lightning and wind cause tree death and injury. Injury and disease cause
many tree deaths. The causes, rates, and patterns of death in tree species are
poorly known, according to Jerry Franklin, despite a hundred years of forest
research. That presents a problem: If we do not know the normal rates of mortality
in a forest, how will we recognize abnormal ones?
Part of the life cycle of a tree is death. The dead trees keep contributing to the
life of the forest, standing for a while (1 to 150 years), then falling and decaying
(over 20-200 years). Ecological forestry accepts a typical percentage of death as
the normal condition, necessary for the renewal of the forest. The rate of death per
year in a mature forest is remarkably constant at about 1-2 percent, even with wind
storms, fires, disease outbreaks, and animal damage. Rotting and burning are an
integral part of the cycle of life and death in the forest. Tree mortality from
pathogens occurs on various scales: gap phases (small scale), forest development
(large scale), and landscape patterns (immense scale). Yet, even catastrophic
disturbances like hurricanes rarely damage more than 5 percent of a forest. More
than being agents of mortality, insects, diseases, and animals are native components
of complex food webs in ecosystems that contribute to the selection of certain kinds
(including healthy) and ages of trees (that determine the composition of the forest,
which changes over time). Mammals and birds disseminate seeds. Insects pollinate
some trees and overwhelm others (rarely more than 1 percent of a forest). Diseases
remove stressed trees (also probably a low percentage on the order of 1 percent).
Pathogens are one of the determinants of growth and development. Their effect on the
long-term health of a forest can only be regarded as positive.
In compiling anecdotal evidence, Little shows that trees are dying throughout every
continent, in greater than normal percentages and for a variety of reasons: Acid
rain in New England, New York, North Carolina, Tennessee, Georgia, Ohio, Indiana and
Kentucky; smog in California; excessive ultraviolet light (through a damaged ozone
layer) in Arizona and New Mexico; rising temperatures and sea levels in Alaska and
Florida; destructive forestry practices, such as clearcutting, in Colorado, Oregon
and Washington; pesticides or toxic heavy metals (released by burning coal and oil)
in many other places, or combinations of all these factors.
Little cites studies by Hubert Vogelmann, a botanist at the University of Vermont,
who wanted to study an undisturbed forest; in 1965 he made a thorough survey of
Camel’s Hump in Vermont’s Green Mountains. He thought he was describing a healthy
ecosystem; he measured the types and sizes of the trees, as well as various other
aspects of the ecosystem. Periodically, he resurveyed Camel’s Hump, and a pattern
began to emerge: The trees were dying. His survey in 1979, compared to the baseline
study of 1965, showed a 48% loss of red spruce; a 73% loss of mountain maple; a 49%
loss of striped maple, and a 35% loss of sugar maple. Vogelmann was able to show
that the health of CamelÂÂs Hump had begun to decline in the period 1950-1960.
Similar studies in the Black Forest of Germany, and in southern Canada, revealed
that the most likely cause was acid rain. (Acid rain was not ½discovered. until
1972, by Eugene Likens and F. Herbert Bormann, although it had been falling on New
York, New England, and southern Canada for about 20 years, as a result of the
massive rise in use of fossil fuels, coal and oil.)
Vogelmann was able to show how acid rain affects the soil and thus the entire
ecosystem, including trees. Soil contains large amounts of aluminum, in the form of
aluminum silicates, which is not available to the roots of plants in that form. But
acid rain dissolves the silicates, releasing the aluminum and making it available.
When trees get aluminum into their roots and their vascular system, the roots clog,
preventing them from taking up adequate nutrients and water. The trees are weakened,
and may then be susceptible to extreme cold, insects or pathogens. Acid rain not
only releases aluminum, it also releases other minerals-calcium, magnesium,
phosphorus-required bytrees; the minerals are washed out of the soil, leaving it
depleted of nutrients.
Furthermore, acid rain kills mycorrhizal fungi, thus further reducing the ability of
trees to absorb water and nutrients. The tree roots provide sustenance to the
mycorrhizal, and the mycorrhizal helps the tree roots gather water and nutrients
from the soil. Acid rain also kills off portions of the detritus food chain. The
detritus food chain is composed of microscopic creatures that compost leaves, twigs,
and pine needles, turning them back into soil. Because the detritus food chain is
damaged by acid rain, forest litter builds up on the floor of the forest. In deep
litter, seedlings cannot take root in the soil. Furthermore, the litter promotes the
growth of ferns, which give off substances that inhibit the growth of red spruce
saplings.
Throughout the book, Little describes studies and statements by the US Forest
Service that downplay the importance of tree disease and death. For example, in 1991
the Procter Maple Research Center at the University of Vermont pinpointed acid rain
and other air pollution as an important cause of decline of sugar maples in Vermont.
The following year the US Forest Service issued a report saying that 90% of the
sugar maples surveyed were healthy and the overall numbers and volume of sugar
maples were increasing (but they had counted only standing dead trees, not those
lying on the ground).
Although Little cites many instances of damage to trees by pollution, other
scientists, such as John Innes in his book “Forest Health,” states that pollution is
not proven to be a major cause of tree death (while admitting many of the declines
from ozone pollution that are also in LittleÂÂs book); Innes suggests that evidence
points to climatic stress and poor site matching. David Perry, in his book “Forest
Ecosystems,” argues that pollution is involved in the decline of many forests, as a
contributing stress, especially in Germany, where 52% of the forests are classified
as diseased (in 1985). Beginning in the 1940s, it became evident that the plantation
system, with single species even-aged trees, was susceptible to catastrophic
change-wind, pollution, insects-in a way that natural forests were not. The forests
began to die as forests-the Germans called this disturbing phenomenon Waldsterben
(forest death). Even into the 1980s, scientists were trying to find the causes of
forest death to preserve the plantation system.
One central question of forest decline or death is whether or not human influences
have accelerated natural mortality rates or caused new mortality. Several scientific
studies have claimed that the evidence for decline due to human causes is
insufficient. The occurrences of forest decline are well-documented from prehistoric
to present times. Over 5000 years ago, elms declined in NW Europe, perhaps from
disease or forest-clearing. From the 1930s to the 1950s, birches in eastern Canada
and northeastern U.S. declined; no single cause has been identified, but stresses
from severe weather are suspected. Starting in the late 1960s, there was a decline
in Ohia trees in Hawaii, possibly from cohort senescence (especially in a
short-lived species colonizing recently disturbed areas, where even-aged stands get
stressed by conditions in a mature forest). In the 1970s and 80s in Germany, forest
death in firs and spruce were the primary factors in this ½forest death. seem to be
air pollution, acidification, and toxic metals; it also occurs in Austria,
Czechoslovakia, France, Italy, Switzerland, Scandinavia, Poland, and England. In the
1970s and 80s, declines of balsam fir in ½fir waves. in Newfoundland and New England
in the US were probably caused by ice damage on the leading edge of the dieback.
Symptoms vary between species, as they should. The causes seem to be combinations of
biotic and abiotic factors. A major factor might be rates of forest clearance,
destruction, and fragmentation, which have been accelerating in the last 100 years.
While scientists admit seeing declines in the vigor of mature forests, leading to
stand-level mortality, they say they cannot make conclusive statements about ½causal
factors.. They mention that forest declines occur in contaminated airsheds, but also
where pollution is not important. There is overwhelming evidence of pollution-caused
death in Europe and eastern United States. The fact that there are other causes that
work independently or with pollution does not invalidate the other evidence. To
argue so, as some scientists do, is based on a logical fallacy, the semantic fallacy
of complexity.
The problem with scientific reasoning is that proof may take many decades and cost
billions of dollars. Although more long-term studies are needed, it might be better
to shift the burden of proof on the safety of industrial processes and products
instead. The concluding paradox that Little identifies: Trees are abundant
everywhere, but dying everywhere. People see trees everywhere and perceive that
there is not a problem with trees dying. The grass is green everywhere too, but
there are fewer species, fewer natives, younger plants, and lower quality material.
Perceptions need to be changed. Little offers details, although some reviewers have
criticized him for not offering enough scientific evidence. Even if Little has not
supported his argument adequately, even if he may be wrong is some instances, the
preponderance of evidence is not easily dismissed. Regardless of the exact causes or
interactions of causes, trees and forests are dying.
His overall suggestions, such as controlling human population growth or stopping
cutting forests, are good common sense suggestions. The greatest threats facing
forests are not just disease organisms or pollution, but the synergistic effects of
fragmentation, pollution, and climate change. And these are best addressed all at
once. Little has described conditions that we need to know about, that we need to
correct or address. Maybe forest death has not been conclusively demonstrated, but
there is sufficient reason to take corrective action now.
A Century of Fire in the West
by George Wuerthner Island Press 2006
Reviewed by Camilla Mortensen
Forest Magazine, Winter 2007
There is a certain irony that the general public’s view of wildfire as
destructive-and even murderous-is shaped by the domestic and kind Smokey Bear, who
warns of the dangers of uncontrolled fires. It is further shaped by Bambi, another
animal with human qualities, whom we remember from our child-hood as the wide-eyed
fawn fleeing with his father from the terrifying forest fire. In sacred narratives
from around the world, animals link humans to fire. According to numerous
mythologies, fire is a gift to mankind, albeit a stolen one. Unlike Smokey and
Bambi, the mythological Raven, Coyote, Rabbit and Spider all are tricksters,
shapeshifters, sacred messengers of the gods and lewd deceivers of men. In addition
to their role as tricksters, they function as “culture heroes” false assumptions
that have shaped forest policy since the early 1900s. George Wuerthner explains
these deceptive hypotheses in his introductory section, using the dichotomy of myth
versus truth.
Technically, the term “myth” does not mean falsehood. Myths are the sacred
narratives from which people derive their worldview. However, the use of the term
myth here points out the deep problem Wuerthner and others face as they seek to
persuade the reader of the ecological benefits of natural fire. The beliefs about
fire Wuerthner refers to as myths range from the idea that fire destroys the forest
and the wildlife, to the conceptions that salvage logging restores the forest, that
grazing prevents fires and finally that fire is simply bad. These beliefs are deeply
entrenched among the public and among lawmakers. They are so deeply rooted in the
public’s psyche that they appear to function in the same way that sacred narratives
do for believers — determining their worldview and their actions.
The dramatic photograph on the cover of Wildfire — of cow elk taking refuge from a
raging fire in the east fork of the Bitterroot River — not only calls up the
aforementioned Bambi, but points to the fascination we have for such fires. The
photo, taken by John McColgan, a fire behavior analyst for the National Interagency
Fire Center, has been widely dispersed on the Internet, resurfacing each time a new
complex of fires receives media attention. The impact of this media attention upon
forest policy is one of the themes Wildfire explores.
The cover photo hints at what the reader will find within-dramatic and beautiful
photographs of the landscape of fire. Wildfire is an intriguing mix of a
coffee-table photo collection, an anthology of scientific analyses of fire and a
passionate plea to move from a fire-industrial complex to a “restoration of a
natural fire regime.” A fire or forest policy aficionado may wish to read straight
through, but anyone with an interest in forests and wildlands will find the book
intriguing to pick up and read at random. The photographs alone make the volume
worthwhile.
The book is divided into seven parts, which explore the main arguments. Part One
lays out the historical relationship humans have with fire, covering topics from
media to the language we use to discuss fire. The second section situates the
discussion both historically and geographically, leading into Part Three, a look at
landscapes of fire around the country. In addition to featuring the forests of the
Rockies and the Cascades that the average reader tends to associate with wildfires,
the photos and essays examine diverse regions such as the southern pines of Florida
and the tundra of Alaska. The photographs in this section succinctly make the
argument that fire does not destroy the land, but is intrinsic to it.
Part Four deals with failed public lands policies such as salvage logging and
livestock grazing. Though the assessments of salvage logging are incisive, the
discussion of livestock receives the least attention, and would benefit from an
analysis of the effects of commercial livestock like cattle versus native and
re-introduced native species such as bison and wild horses. The fifth section
features critiques of the “fire-military-industrial complex” and furthers the
arguments about the financial incentives behind fire policies. Part Six poses
alternatives to current fire policies, and does what many volumes on controversial
topics fail to do-offers proactive solutions rather than dwell on criticism. The
final portion of the book pulls together the various arguments in the volume, while
adeptly addressing the difficulties that lie ahead in changing the mind of the
American public.
The control of fire seems to be intrinsic to our conception of what it is to be
human. What this book seeks to overturn are the contemporary mythologies that allow
us to believe that all fire can and must be suppressed, controlled and even turned
to profit. Perhaps if one looks to the tales of the trickster giving fire to man,
one might remember that a trickster is a deceiver as well as a giver, and man is a
fool if he continues to believe that something as powerful in nature as fire could
or should be controlled by mere humans.
Camilla Mortensen is a folklorist and a freelance writer who works on issues of
conservation and cultural heritage.
THE AGE (Melbourne, Australia) www.theage.com.au
January 31, 2007
Warming world turns up the heat on nature
Jo Chandler
Six years ago, Lesley Hughes published a paper blowing the whistle on what a
fraction of a degree of warming was doing to the natural world. Now, with
international scientists about to release a report anticipating temperature
increases of three to five degrees in the next century, Dr Hughes is looking ahead
to what will be required to rescue species.
Things like enlarging the national parks network or changing land-use patterns to
allow plants and animals to move where they must to find conditions for survival as
temperature and rainfall change. And even uprooting plants and animals from places
where they no longer thrive and moving them somewhere they might have a chance.
“I think the single most important management strategy we can put in place is to
connect up, or improve or reconnect, areas of habitat that have been fragmented,”
says Dr Hughes, a specialist on the impact of climate change at Sydney’s Macquarie
University. She is also a key contributor to the next report of the
Intergovernmental Panel on Climate Change. The first section of the report, the most
authoritative summary on the state of the planet yet produced, will be released in
Paris on Friday.
“The next hurdle is to decide what to do about it. For me the bottom line is to stop
species going extinct. So we need to focus on what we can do to improve
opportunities for species to adapt.”
One option for some species would be to move them to places where they might survive
– a strategy long employed to save big animals on the brink of extinction in such
places as Africa. “A lot of ecologists and conservationists are very resistant to
the notion of engineering the environment,” Dr Hughes says. “In a perfect world we
would not do it, but if the alternative is to lose a species, then we need to be
broadminded enough to do that.”
But it is a last-ditch option, and not desirable or even possible for most species,
says Dr Hughes, particularly given that all species rely for their existence on
other species in some way,and climate change is already eroding some of those
relationships. She cites the example of oaks in the Netherlands now producing their
spring leaves earlier. The caterpillar that feeds on those leaves is also coming out
earlier to capitalise on the growth, but the bird that feeds the caterpillars to its
young has yet to get the message. By the time the birds’ young hatch, the food
source is well past its peak.
In 2000, Dr Hughes published research in the journal Trends in Ecology and
Evolution, which drew on a wide range of isolated data on various species – bird
migration rhythms, plant growth and shifts in habitat of creatures from butterflies
to mammals – and found the physiology, distribution and phenology (the timetable for
budding, breeding etc) of species was already affected by the changing atmosphere.
“The most sobering thought is that even if only a fraction of the examples reviewed
here are indeed a result of the enhanced greenhouse effect, they have occurred with
warming levels at only one-fifth, or less, of those expected over the next century,”
the paper concluded.
In Australia, these changes have emerged from a warming of just 0.8 degrees recorded
since 1910. “It doesn’t sound like much, but temperature is used as a trigger in
lots of events in species’ life
cycles – like flowering or laying eggs or hatching,” Dr Hughes says. “Fairly modest
increases to temperature are already causing quite big advances in when things
happen during the year. Spring comes earlier, lots of plants are flowering earlier,
we’ve found lots of birds migrating to Australia earlier and leaving later, insects
are hatching earlier. All those temperature-sensitive events are quickening up.”
Dr Hughes was co-author, with Macquarie colleagues, of another report last year
which found that Australian migratory birds were, like birds in Europe, arriving an
average 3ˆdays earlier and leaving later.
“The take-home message is that small temperature changes have had big impacts,” she
says. “So translate that to what may happen in the next century, with maybe five or
six times the warming we’ve already had, and our natural world will really change
profoundly.”
Copyright © 2007. The Age Company Ltd.
SCIENCE www.sciencemag.org
2 FEBRUARY 2007 VOL 315
Technical comment
Comment on ” Rapid Advance of Spring Arrival Dates in Long-Distance
Migratory Birds ”
Christiaan Both
Jonzén et al. (Reports, 30 June 2006, p. 1959) proposed that the rapid advance of
spring migration dates of long-distance migrants throughout Europe reflects an
evolutionary response to climate change. However, most migrants should not advance
their migration time because the phenology of their breeding grounds has not
changed. It is more likely that migration speed has changed in response to improved
environmental circumstances.
One of the great ecological concerns about climate change is that the phenology of
different trophic levels responds at different rates (1), causing a mismatch between
the timing of peak food requirements and peak food availability (2, 3). My
colleagues and I have argued that long-distance migratory birds in particular have
problems in responding appropriately to climate change. At their wintering grounds,
migrants cannot accurately predict the phenology of their breeding grounds and, as a
solution, they have evolved clock mechanisms to start their spring migration (4).
These endogenous mechanisms have become maladaptive because of climate change, and
at present birds arrive too late at their breeding sites(5). A change in migration
time requires either an evolutionary change in the time of year that clocks instruct
the birds to fuel and go or a phenotypic reaction to changed environmental
conditions.
Jonzén and co-workers (6) recently showed that African-Palearctic long-distance
migrants have advanced their spring migration time through Italy and southern
Fennoscandia, and they argued that this is the expected evolutionary change. This is
an important claim, suggesting that the inadequate timing responses may be only
temporary and that at present rapid evolution solves the birds’ problems. I agree
that the observed advances are an interesting phenomenon and that an evolutionary
response in migration time is indeed expected. However, I strongly disagree that the
observed effects are caused by such an evolutionary response.
An evolutionary change is a change in gene frequencies within populations, and in
the present case it requires genetic variation for migration time as well as
consistent selection for early migration. We showed that selection for early
breeding and arrival increased for Dutch pied flycatchers Ficedula hypoleuca in
response to climate change (5), and Jonzén et al.(6) used this as the backbone for
their suggestion of evolutionary change. However, they failed to take into account
key information about the precise breeding populations to which the study birds
belonged. Most species examined have their distributional center of gravity in
Fennoscandia and Northern Russia (7, 8), where spring temperatures have not
increased during the last decades and egg-laying dates have not advanced (9). This
lack of change in selection for early arrival and breeding makes the suggested
evolutionary response unlikely.
Two alternatives can explain the observed changes in migration time: (i) migration
is faster because environmental conditions during migration improved, or (ii) the
mixture of birds from different breeding populations changed, and these populations
differ in migration dates. Jonzén et al.(6) have overlooked the second hypothesis,
but they discuss and reject the first option, assuming it unlikely that climate
change has improved conditions for migration in Africa. However, improved conditions
in North Africa may be responsible for the advanced passage through Italy, because
they correlate with arrival and breeding in several migrants (10, 11). Furthermore,
rainfall has increased in the Sahel since the early 1980s (12), probably improving
conditions during migration for many species.
In conclusion, the suggestion of a climate-driven evolutionary change (6) is weak
because phenotypic responses are likely, and selection for earlier arrival and
breeding has not increased in the majority of populations studied by Jonzén et al.
There is little doubt that evolutionary changes will occur in the near future, but
it is difficult to predict whether these will be sufficient to meet the requirements
of climate change. Even if we accept the assertion of an evolutionary response, for
pied flycatchers the advance in passage time through Italy (0.21 days per year) is
still far less than the advance of their food peak on the Dutch breeding grounds
(0.78 days per year) (13).
References and Notes
1. G. R. Walther et al., Nature 416, 389 (2002).
2. M. E. Visser, C. Both, Proc. R. Soc. Lond. B. Biol. Sci. 272, 2561 (2005).
3. C. Both, S. Bouwhuis, C. M. Lessells, M. E. Visser, Nature 441, 81 (2006).
4. E. Gwinner, Ibis 138, 47 (1996).
5. C. Both, M. E. Visser, Nature 411, 296 (2001).
6. N. Jonzén et al., Science 312, 1959 (2006).
7. G. Zink, Der Zug Europí¤ischer Singví¶gel. Ein Atlas der Wiederfunde beringter
Ví¶gel (Vogelzug-Verlag, Mí¶ggingen, 1973).
8. E. J. M. Hagemeijer, M. J. Blair, The EBCC Atlas of European Breeding Birds:
Their Distribution and Abundance (T & AD Poyser, London, 1997).
9. C. Both et al., Proc. R. Soc. Lond. B. Biol. Sci. 271, 1657 (2004).
10. C. Both, R. G. Bijlsma, M. E. Visser, J. Avian Biol. 36, 368 (2005).
11. A. P. Moller, T. Szep, J. Evol. Biol. 18, 481 (2005).
12. M. Hulme, R. Doherty, T. Ngara, M. New, D. Lister, Climate Res. 17, 145 (2001).
13. C. Both, M. E. Visser, Glob. Change Biol. 11, 1606 (2005).
14. I thank T. Piersma for comments on an earlier version.
This research is supported by a VICI grant (to J. Komdeur)
and a VIDI grant (to C.B.) from the Dutch Science
Foundation (N.W.O.).
10 October 2006; accepted 22 December 2006
10.1126/science.1136148
————————-
Response to Comment on ” Rapid Advance of Spring Arrival Dates in
Long-Distance Migratory Birds ”
Niclas Jonzén,1 Andreas Lindén,2 Torbjí¸rn Ergon,4 Endre Knudsen,4 Jon Olav Vik,4
mDiego Rubolini,5 Dario Piacentini,6 Christian Brinch,4 Fernando Spina,6 Lennart
Karlsson,7 Martin Stervander,8 Arne Andersson,8 Jonas Waldenstrí¶m,9 mAleksi
Lehikoinen,3 Erik Edvardsen,10 Rune Solvang,10 Nils Chr. Stenseth 4 *
*To whom correspondence should be addressed. E-mail: n.c.stenseth@bio.uio.no.
Both’s comment questions our suggestion that the advanced spring arrival time of
long-distance migratory birds in Scandinavia and the Mediterranean may reflect a
climate-driven evolutionary change. We present additional arguments to support our
hypothesis but underscore the importance of additional studies involving direct
tests of evolutionary change.
Both (1) questions our suggestion that the advanced spring arrival time of long-
distance migratory birds in Scandinavia and the Mediterranean may reflect a
climate-driven evolutionary change (2). A key premise of our interpretation is that
spring is arriving earlier in the breeding areas we considered and that most birds
are laying eggs earlier than before. Yet Both argues that the species we studied
breed mainly in Fennoscandia and northern Russia, where springs have not become
warmer, nor has egg-laying advanced. However, recovery of birds banded at the Nordic
observatories and at Capri clearly show that Scandinavia (and, to some extent, the
Baltic) is where most individuals of the studied species breed (3-7). Overall,
contrary to Both’s assertions (1, 8), it is well documented that spring green-up
advanced by about 0.5 days/year from 1982 to 2001 in most of Scandinavia and western
Russia (9). This is likely to have contributed to earlier peak insect abundance for
breeding migrants. Likewise, April and May were warmer between 1991 and 2005 than in
the period 1961 to 1990 in Sweden (10). However, trends in spring timing do vary
within regions, with spring coming later in snow-rich mountain areas, for example
(9).
Both (1) suggests two alternative explanations for the observed change in migration
timing of long-distance migrants, neither of which are supported by the available
evidence. His first suggestion is that the sizes of populations arriving early might
have increased relative to later-arriving populations of the same species. In
general, the populations breeding farthest to the north are the last to migrate
through our study sites (11). If such populations in most species were declining
relative to earlier-arriving populations, this might explain our results. However,
there is no evidence that this has generally occurred. In Finland, populations have
increased in the south relative to the north only in two of the seven long-distance
migrant species included in our study (12).
Both also suggests that spring migration could be faster as a result of improved
ecological conditions en route (13), such as increased Sahel rainfall and North
African spring temperatures (1, 13). However, a reanalysis of our data from Capri
indicates that the observed advance in migration dates is unaffected by taking these
seemingly favorable conditions into account (14). The possibility that some
unmeasured environmental cue might have induced a phenotypic shift in the onset of
migratory activity or speed of migration in Africa cannot be ruled out.
Nevertheless, our result is suggestive, and the next step would be to search for
direct evidence of microevolution. For instance, a comparison of individual-and
population-level changes in phenotypic traits may quantify to what degree the
observed changes in mean phenotypic traits are caused by plasticity or genetic
adaptation (15).
Both (1) argues that our report suggests that the inadequate timing responses may
only be transient and that rapid evolution may solve the birds’ mismatch of arrival
time and peak food availability (2). However, such perfect compensation is not to be
expected. The optimal temporal shift in arrival date is always less than the shift
in the food peak date because of the survival costs of early arrival (16). Hence,
despite an evolutionary response, bird populations might still face a temporal
mismatch of resources and breeding, which may cause population declines (17). In our
view, phenotypic plasticity and evolutionary response are not mutually exclusive,
and the latter remains a likely explanation for the general trend of earlier
springtime arrival of long-distance migrant birds.
References and Notes
1. C. Both, Science 315, 598 (2006); www.sciencemag.org/
cgi/content/full/315/5812/598b.
2. N. Jonzén et al., Science 312, 1959 (2006).
3. V.Bakken,O.Runde,E.Tjí¸rve, Norwegian Bird Ringing Atlas, Vol. 2
(Stavanger Museum, Stavanger, Norway, 2006).
4. Swedish Museum of Natural History, Bird Ringing Centre, www.nrm.se/rc.
5. Finnish Museum of Natural History, Finnish Ringing Centre,
www.fmnh.helsinki.fi/english/zoology/ringing.
6. Italian Ringing Centre, Istituto Nazionale per la Fauna Selvatica, www.infs.it.
7. N. Jonzén et al., Ornis Svecica 16, 27 (2006).
8. C. Both et al., Proc. R. Soc. Ser. B 271, 1657 (2004).
9. R. Stí¶ckli, P. L. Vidale, Int. J. Remote Sens. 25, 3303 (2004).
10. The Swedish Meteorological and Hydrological Institute, Fact sheet no. 29 (in
Swedish) (2006).
11. A.Hedenstrí¶m,J.Pettersson,Ví¥r Fí¥gelví¤rld 43, 217 (1984).
12. R. Ví¤isí¤nen, Linnut-vuosikirja 2005, 83 (2005).
13. C. Both, R. G. Bijlsma, M. E. Visser, J. Avian Biol. 36, 368 (2005).
14. The linear trend in on the median arrival date, when taking into account the
Sahel wet season (June to October) rainfall, the mean of February to April
temperatures at Tunis, and the winter North Atlantic Oscillation (2), was -0.27
days/year (95% confidence interval, -0.40 to -0.15; the species set is considered as
fixed, and the variance of the mean is calculated from the uncertainty of the
species-specific effects), which is in line with the temporal trend reported in (2).
Meteorological information was obtained from (18)and(19) for Sahel rainfall and
Tunis temperature, respectively.
15. A. P. Mí¸ller, J. Merilí¤, Adv. Ecol. Res. 35, 111 (2004).
16. N. Jonzén, A. Hedenstrí¶m, P. Lundberg, Proc. R. Soc. Lond. B.
Biol. Sci. 274, 269 (2007).
17. C. Both, S. Bouwhuis, A. Offermans, C. M. Lessells, M. E. Visser, Nature 441, 81
(2006).
18. Joint Institute for the Study of the Atmosphere and Ocean,
http://jisao.washington.edu/data_sets/sahel.
19. National Oceanic and Atmospheric Administration,
National Climate Data Center, Global Historical Climatology
Network, version 2; http://iridl.ldeo.columbia.edu/
SOURCES/.NOAA/.NCDC/.GHCN/.v2.
27 October 2006; accepted 29 December 2006
10.1126/science.1136920SCIENCE www.sciencemag.org
Institute for War and Peace Reporting
29-Jan-07
News Briefing Central Asia
Glaciers Melting Due to Habitat Destruction
Ecologists are warning that the destruction of vegetation in Tajikistan’s highest
mountain areas is destroying the local environment and increasing the risk of
glacial melting.
The Pamir Media news agency reported on January 20 that the eastern Pamir mountains
are losing their sparse covering of bushes as people cut the plants to burn as fuel.
In the Murgab area of Badakhshan, in eastern Tajikistan, for example, the local
“teresken” plant has been almost completely wiped out within an 80 kilometre radius
of the villages there, as people have no other source of fuel.
The news agency warned that since these bushes are the only form of vegetation in
the area, the area is likely to turn into a desert.
Davlatshoh Gulmahmadov, director of the government’s agency for land improvement and
cartography, says over 97 per cent of the land in Tajikistan is at risk of
degradation due to uncontrolled deforestation.
“People cut down trees and destroy other plants, which leads to landslides,
avalanches, floods and mudslides, causing erosion,” said Gulmahmadov.
Saulius Smalis, an environmental advisor with the OSCE in the capital Dushanbe, says
it is not just deforestation, but the gradual destruction of pasture lands, that
leads to the risk of desertification.
Ecologists warn that the destruction of mountain vegetation has a global impact.
“When the bushes are destroyed, this [loosening of soil] can lead to dust storms in
the eastern Pamirs. The dust settles on glaciers and they [absorb more heat and]
melt more rapidly,” says Svetlana Blagoveschenskaya, an ecologist and biologist
expert working on a European Union environmental project.
The Pamir Mountains are home to Central Asia’s largest glaciers, which feed the Amu
Darya, one of the region’s two great rivers.
Blagoveshenskaya says deforestation will only end when the Tajik government starts
providing people with alternative sources of fuel.
Gulmahmadov told NBCentralAsia that the government adopted a national action
programme for combating desertification back in 2001 – but there are no funds
available to implement it.
(News Briefing Central Asia draws comment and analysis from a broad range of
political observers across the region.)
CONTRA COSTA TIMES
Posted on Thu, Jan. 25, 2007
DEGREES OF CONCERN: DAY FIVE
Animals on the edge
By Betsy Mason
CONTRA COSTA TIMES
The heart of the climate change matter can be found in a plastic bucket full of
porcelain crabs.
Perfectly adapted to the high and low temperature extremes of lives spent half in
and half out of the Pacific Ocean, these little crustaceans might not survive if the
highs get any higher.
“They’re kind of living on the edge already,” said ecological physiologist Jonathan
Stillman.
The crabs, and many other California animals, are already feeling the heat — and
responding.
Some species, from the coastal crabs to chipmunks in the peaks of the Sierra, have
already begun shifting their ranges northward or to higher elevations to compensate
for warmer temperatures. But both man-made and natural barriers present sometimes
insurmountable challenges and for some species, that strategy is destined to fail.
Climate change can be a powerful catalyst for evolution, as evidenced by the many
species that have evolved over thousands and millions of years to fill very specific
niches in California’s myriad microclimates.
But some of these species may see their habitats disappear faster than they can
evolve. If change at the current pace continues, it could lead to mass extinctions
of animals and plants.
The evidence that animals are already being affected by climate change is piling up
as scientists study species all over the state.
Crab cardio
Stillman has a knack for spotting the rocks most likely to have scores of porcelain
crabs hiding beneath them. Efficiency is key to gathering enough of the leggy
brownish-grey critters before the evening tide comes in and immerses the bouldery
intertidal crab haven.
On a trip to Fort Ross in September, Stillman brought an SUV full of graduate
students with buckets to help him catch the 300 or so speedy, slippery crabs he
needed to sustain his research for several months.
The crabs were headed for Stillman’s laboratory at San Francisco State University’s
Romberg Tiburon Center, where they would have their ability to withstand heat put to
the test. These little crustaceans, usually no more than two inches across, are
ideal for Stillman’s research because there are many species that thrive in
different temperature ranges all along the Pacific Coast.
Porcelain crabs live in intertidal zones, and when the tide goes out on a hot, sunny
day their body temperature can go up as much as 45 degrees in six hours. The crabs
have evolved to tolerate extreme temperature swings, but this comes at the expense
of being able to withstand temperatures outside of their normal range.
“If it gets a little hotter, they might not be able to respond physiologically,”
Stillman said.
In his lab, Stillman measures the crabs’ heart beats with electrodes passed through
holes made in their shells while they go through temperature trials.
To find their baseline capacity to handle heat, Stillman puts crabs into a tank set
at a temperature near the low end of what they experience in their natural habitat.
He then slowly turns up the heat to mimic an extremely hot day. The crabs’ hearts
beat faster and faster as the water gets hotter until at some point they start to
fail and slow down.
“That’s what we call the critical temperature,” Stillman said. “It’s sort of the
point of no return.”
The goal is to see how much these animals can adjust their point of no return to
adapt to hotter conditions. After allowing another set of the same species of
porcelain crabs to acclimate in a tank with an average temperature at the high end
of temperatures in their natural habitat, Stillman puts them to the heat tolerance
test again.
He has done this with more than 20 porcelain crab species, and it turns out some can
adjust more than others.
Crabs that already live in the hottest habitats can only raise their upper threshold
by about 1.6 degrees more when acclimated to the hotter temperatures than at the
cooler end.
But crabs that normally live in cooler habitats can push their limit up by 4.5 degrees.
The porcelain crabs living on the coast between Monterey and Fort Ross are in the
middle of the spectrum with a critical temperature around 89.5 to 91.5 degrees, and
Stillman has measured 89.5 degrees in their habitat on occasion
“The intertidal species around here are definitely potentially experiencing some
temperatures that are close to what their thermal limits are,” Stillman said. “If it
gets just a little hotter on the hottest days, or if those days start occurring more
regularly or in longer stretches like we had this summer — and both of those things
are predicted as a consequence of global warming — then these animals are really
going to start feeling it,”
he said.
It took millions of years for the various porcelain crab species to evolve to live
in their specific habitats, but evolution won’t be able to keep up with the current
rate of climate change.
“Global warming is happening way faster than just about anything is going to be able
to respond on an evolutionary timescale,” Stillman said. “A million years is pretty
fast for evolution.”
Stillman views his work with the crabs as a case study of how temperature affects
animals that live in the intertidal zone in general, and many other species will
likely share their fate.
The only remaining options for some species are to move or go extinct.
One bad day
Many animal species in the ocean and on land already are responding to climate
change by moving to cooler habitats.
In Monterey Bay, for example, scientists have documented a change in the types of
species that parallels a change in temperature, up an annual average of 1.35 degrees
on the surface since the 1920s, and up 4 degrees during the peak summer months.
“That may not seem like a heck of a lot to people because our body temperatures can
shift by that much,” said physiologist George Somero of Stanford University’s
Hopkins Marine Station near Pacific Grove. “But these animals are living on the edge
of their thermal tolerance, and it’s a real challenge to some of them.”
From 1931 to 1933, a graduate student at Hopkins Marine Station named Willis Hewatt
identified and counted species in 1 yard square quadrants along a transect through
the tidal zone in Monterey Bay. Sixty years later, a group of scientists led by
James Barry of the Monterey Bay Aquarium Research Institute returned to Hewatt’s
transect. The study, published in the journal Science in 1995, showed the overall
number of species and density of animals had not changed, but the makeup of the
populations was different.
“There was a shift from species that were more cold adapted to more warm-adapted
species. So species that typically would be found down towards Santa Barbara, Los
Angeles were in greater abundance here. Those that you would expect to find around
Oregon, but would also occur here, were reduced in abundance,” Somero said.
“We’re quite sure that these changes that have occurred in the distribution patterns
of animals have quite a lot to do with the fact that some animals are now facing
temperatures that they’re just not evolved to face.”
One species that has become significantly more scarce in Monterey Bay is the
porcelain crab Stillman collected at Fort Ross. Other porcelain crab species also
appear to have shifted north, and a few species seem to have moved deeper from
intertidal zones to cooler subtidal zones.
Shifting north has its problems for some species, however. Low tides along the
central California coast normally occur early and late in the day when the sun is
less intense. But further north, such as in the Puget Sound area, low tide is closer
to the middle of the day.
This is particularly bad for animals such as snails and mussels that move slowly and
can’t get out of the hot sun.
“It just takes one bad day, or maybe one bad hour, as far as overheating and dying
are concerned,” Somero said.
Without a safe northern escape route, these animals’ ranges may shrink rather than
shift.
Moving on up
Similar patterns are being documented among animals in California’s mountains.
Biologists at the Museum of Vertebrate Zoology at UC Berkeley have been
painstakingly counting animals in Yosemite, Lassen and other wilderness areas in
California as part of an ambitious project to retrace the steps of the museum’s
first director, Joseph Grinnell, who set out to count and catalogue the state’s
wildlife more than 80 years ago.
His team took thousands of pages of field notes, snapped thousands of photos and
collected thousands of animal specimens from more than 700 sites across the state;
all of the specimens are still housed in the museum.
Grinnell’s aim was to document what was living where in California in the early part
of the century so that future scientists would be able to recognize the changes he
was sure would occur. His foresight is paying off for UC Berkeley biologists John
Perrine and Jim Patton who have been revisiting the spots that Grinnell surveyed to
see if things have changed.
They have.
During four years of surveying animals in Yosemite National Park, Patton has seen
some of the changes predicted as a response to warming. In particular, several
high-elevation species appear to have retracted their ranges upward.
The alpine chipmunk, found only in California’s high Sierra, was spotted by Grinnell
at an elevation of 7,700 feet. Patton’s team hasn’t found the chipmunk lower than
9,700 feet.
“Since they can’t go any higher than the tops of these mountains, if they keep
retracting upward, eventually they’re going to go extinct,” Patton said. “Is that
something that’s of concern to people? I would hope so.”
Belding’s ground squirrels have also withdrawn their range upward by around 1,500
feet and the golden mantle ground squirrel has lost several hundred feet of
elevation at the lower end of its range as well.
Patton found that the pika, a hamsterlike cousin of the rabbit, has withdrawn the
lower limit of its range up 1,500 feet, a change seen in pika populations in
mountain ranges throughout the west, resulting in local extinctions of some
populations.
“These are animals that are apparently very sensitive to temperature increase, and a
few degrees of temperature increase in the summer can cause death of individuals,”
Patton said.
At the same time, species typically found at lower elevations are appearing at much
higher elevations than before. The pinion mouse, which didn’t exist in Yosemite
National Park in Grinnell’s day, has expanded the upper limit of its range from
outside of the park around 7,800 feet up into the park as high as 10,500 feet.
“I trapped the first one up on Mt. Lyell,” Patton said. “When I saw it, I thought,
‘What in the world is this animal doing up here? It’s not even close to its
habitat.’ That was a real surprise.”
It’s possible that for any of these species, Grinnell and Patton happened to survey
them at opposite ends of a natural fluctuation in population size. But as more and
more species appear to follow the same pattern over a series of years, the
likelihood of the shifts being natural diminishes.
Last year, Perrine began retracing Grinnell’s trek through Lassen Volcanic National
Park and early indications are that the pattern of habitat shifts will berepeated
there.
“We are seeing a few little signals that appear consistent,” Perrine said. For
example, the California ground squirrel has expanded its range to higher elevations
in both parks. But heavy winter snows made surveying at higher elevations difficult
and Perrine hopes to revisit the area in 2008 to get a better picture.
Patton has already moved on to the White Mountains east of Mono Lake. And the team
was recently granted $570,000 for four years from the National Science Foundation to
survey more than 50 sites along the spine of California’s mountains from Mt. Shasta,
the Trinity Alps and the Warner Mountains in the north, through Lassen and Tahoe, to
Yosemite and the Sequoia and Kings Canyon National Parks in the south.
“That will really tell us if some of the Yosemite patterns are statewide,” Perrine
said.
And if the high-altitude range retractions are pervasive, that will be another clue
global warming is the likely cause.
“I don’t know what else would explain that,” Patton said.
© 2007 ContraCostaTimes.com and wire service sources. All Rights Reserved.
GULF NEWS (Dubai, United Arab Republics)
January 24, 2007
Let us make peace with our planet
http://archive.gulfnews.com/opinion/columns/world/10099181.html
By Koichiro Matsuura, Special to Gulf News
We know now that our civilisation, our species and even our planet may not be
immortal. This is not the first ecological crisis that humanity has lived through,
to be sure; but there can be no doubt it is the first that is so wide – indeed,
world-wide – in scope. What are we doing to safeguard the future of the Earth and
its biosphere? What are the challenges to be met? What solutions can we offer? These
were the questions under discussion in the latest session of our 21st Century
Dialogues organized by Jereme Binde at the Unesco Headquarters on the theme “What
future for the human species? What prospects for the planet?”, with contributions
from some 15 leading experts.
First and foremost, climate change and global warming: by the end of the century
this planet could be hotter by an amount between 1.5ˆÃc®’C and 5.8ˆÃc®’C. Such a
warming of the climate threatens many parts of the world and is liable to provoke
further disasters from the proliferation of tropical storms to the drowning of whole
island states or coastal
regions.
Next comes desertification, already affecting a third of the world’s land. At the
end of the 20th century almost one billion people in 110 countries were threatened
by encroaching deserts: the figure might well double by 2050, when two billion could
be affected.
Deforestation is continuing, too, though primary and tropical forests are home to
the greater part of the world’s biodiversity, and we know they help to combat
climate change as well as slowing soil erosion.
The whole biosphere is threatened by pollution: pollution of air and water, oceans
and soils, chemical pollution and invisible pollution. In Asia alone, the World Bank
estimates the cost in human life of atmospheric pollution at 1.56 million deaths a
year.
There is a world water crisis that cannot be ignored. Two billion people will face
water shortages in 2025 – three billion, in all likelihood, by 2050.
Lastly, biodiversity is endangered: species are becoming extinct a hundred times
faster than the mean natural rate, and 50 per cent of all species could be gone by
2100. Yet biodiversity is essential to the cycle of life, to human health and to the
security of our food supply.
This situation brings a serious risk of war and other conflicts and demands a global
response. Sustainable development concerns us all: it is a necessary condition for
any effective fight against poverty, not least because it is the poorest who will
suffer the worst of the droughts and other natural disasters to come.
Today, though, we understand that our war on nature is a world war. That is the
meaning of the Stern Report on the economic consequences of climate change. If we do
not take immediate action to combat global warming, we can expect to forgo between 5
per cent and 20 per cent of world GDP by 2150: the bill comes to some 5,500 billion
euros. Who says sustainable development costs too much?
“Business as usual” is what threatens to ruin us! Javier Perez de Cuellar began our
21st Century Dialogues with a clear warning: “How can we know, yet be unable – or
unwilling – to act?”.
There are difficult questions that we have to answer now, with courage and lucidity.
It can no longer be argued that “sustainability” and “development” are conflicting
goals, nor that tackling poverty is incompatible with conserving ecosystems. We are
going to have to fight on every front at once.
We shall also have to invent new and far more wisely restrained modes of growth and
consumption. As Haroldo Mattos de Lemos emphasized in the 21st Century Dialogues,
“we humans are no longer living off nature’s interest, but off its capital”. The
idea is not, of course, to stop growth entirely, but, as Mustafa Tolba suggested, to
bring about the quickest possible shift in its nature towards less material forms of
wealth, reducing our consumption of raw materials in every area of production. There
must also be far greater awareness of the devastating potential of global warming;
and that awareness must result in compliance with the measures laid down in the
Kyoto protocol.
It would also be useful to promote a right to clean drinking water, laying a proper
foundation for the ethical governance of water so that it becomes possible both to
control demand and to manage it better, as well as improving water quality through
careful use, proper treatment and recycling.
The call for us, today, to put an end to the war on nature is a call for an
unprecedented solidarity with future generations. Perhaps, in order to achieve this,
humanity needs to make a new pact, a “Natural Contract” of co-development with the
planet, and an armistice with nature.
Koichiro Matsuura is the director-general of Unesco.
VOICE OF AMERICA
05 January 2007
Kenya Experiencing the Effects of Deforestation, Climate Change
By Cathy Majteny
Nairobi – The U.N. Climate Change Conference, held recently in Nairobi, Kenya,
renewed the world’s attention to what is commonly known as global warming, which
most scientists say is caused by carbon dioxide and other greenhouse gas emissions
largely coming from rich countries. But experts say deforestation in developing
countries such as those in Africa also exacerbates the effects of climate change.
The Lake Naivasha area of Kenya is experiencing many of the effects of climate
change, as Cathy Majtenyi reports.
Giraffes, wildebeest, and other animals graze lazily on a plain in Kenya’s Rift
Valley, about an hour north-west of the capital Nairobi.
There was a time when the light green plain in the distance was under water, as an
inlet of Lake Naivasha - one of several lakes in the Rift Valley.
Sarah Higgins, a farmer and environmentalist with the Lake Naivasha Riparian
Association, says she has seen many changes in her farm’s landscape since moving
here 36 years ago.
“We have seen the area that we work in drying up – definitely,” she said. “We used
to guarantee our rain every year, so we could guarantee our crop. But now this is
not happening; now we are drying up.”
Lake Naivasha normally has cycles of rising and falling water levels, but Higgins
says she and other farmers in the area have observed that these cycles have been
disrupted.
The water that fills Lake Naivasha comes from rivers and streams originating from
the Abederes mountain range that forms the eastern wall of the Rift Valley.
The Aberdares used to be covered by thick forests that trapped moisture, kept
temperatures cool, and performed other functions including supplying plentiful
rainfall to the area.
But massive deforestation has taken place in the Aberdares range and other wooded
areas in Kenya over the past few decades.
The deforestation has come about from people clearing the land for farms, timber
merchants over-logging, government selling or giving away large tracts of forest in
corrupt deals, and other forms of mismanagement.
This has caused many of the rivers and streams feeding Lake Naivasha and other lakes
to shrink or dry up, leading to a drop in water levels.
There is also less rain in the area, in part because there is less forest cover to
trap moisture and attract cloud cover.
John Njoroge, a farmer and conservationist in the Aberdares area, points out grassy
plains in the nearby hills that once were forested,
but have since been burned and cleared by the local community.
Njoroge says he has noticed less rain and changing rainfall patterns.
“We have just now witnessed a change for about one-and-a-half years near Kinangop
[forest] without rain,” he said. “And some years back, it was just raining about
three times a year. We are just expecting [rains] now in March and October, but now
we are just getting one season rain around in December, which is just raining
accidentally.”
Deforestation is one of several human activities that experts say contribute to
climate change.
They are especially worried that the emissions of carbon dioxide, methane, and other
gases into the air are forming a barrier that prevents the sun’s energy from
radiating back into space, thus raising the earth’s temperature.
These scientists blame climate change for causing more intense and frequent
droughts, floods, hurricanes, rising sea levels, and other negative effects in
different parts of the world.
In a poor country like Kenya, the cheapest and most efficient way to mitigate the
harmful effects of climate change is to have lots of trees. Trees absorb excess
carbon dioxide and other harmful gases from the atmosphere. But when trees are cut
down, this process is halted.
The effects of deforestation and changes to the atmosphere, in turn, have caused
hardship for the local population.
Kenya Wildlife Service scientist James Mathenge describes what he has witnessed in
the Aberdares and another water catchment area called the Mau forest.
“The effects of climate change that I have seen in this area is that there is, one,
loss of species, that is both plants and animals due to drought, it’s prolonged
drought, and these ones, they are really causing this ecosystem to lose a lot of
biodiversity in terms of big
mammals and small mammals and also in terms of the plants,” said Mathenge.
Experts agree that planting trees is the best way to restore forest cover in Kenya
and other parts of Africa. Trees, in turn, are expected to mitigate some of the
local effects of climate change.
Kenyan Environment Minister Kivutha Kibwana admits that deforestation is a huge
problem in his country – but says a new forestry law has just been enacted.
“We are in the process of really reversing previous policy so that people know that
you can’t destroy forests and get away with it,” said Kibwana. “The government will
not dish out forest land to you.”
In the meantime, people like conservationist John Njoroge are planting seedlings and
doing what they can to tackle the menace of climate change, one tree at a time.
3. Oceans of the World in Extreme Danger
Oceanic problems once found on a local scale are now pandemic. Data from
oceanography, marine biology, meteorology, fishery science, and glaciology reveal
that the seas are changing in ominous ways. A vortex of cause and effect wrought by
global environmental dilemmas is changing the ocean from a watery horizon with
assorted regional troubles to a global system in alarming distress.
According to oceanographers the oceans are one, with currents linking the seas and
regulating climate. Sea temperature and chemistry changes, along with contamination
and reckless fishing practices, intertwine to imperil the world’s largest communal
life source.
In 2005, researchers from the Scripps Institution of Oceanography and the Lawrence
Livermore National Laboratory found clear evidence the ocean is quickly warming.
They discovered that the top half-mile of the ocean has warmed dramatically in the
past forty years as a result of human-induced greenhouse gases.
One manifestation of this warming is the melting of the Arctic. A shrinking ratio of
ice to water has set off a feedback loop, accelerating the increase in water
surfaces that promote further warming and melting. With polar waters growing fresher
and tropical seas saltier, the cycle of evaporation and precipitation has quickened,
further invigorating the greenhouse effect. The ocean’s currents are reacting to
this freshening, causing a critical conveyor that carries warm upper waters into
Europe’s northern latitudes to slow by one third since 1957, bolstering fears of a
shut down and cataclysmic climate change. This accelerating cycle of cause and
effect will be difficult, if not impossible, to reverse. Atmospheric litter is also
altering sea chemistry, as thousands of toxic compounds poison marine creatures and
devastate propagation. The ocean has absorbed an estimated 118 billion metric tons
of carbon dioxide since the onset of the Industrial Revolution, with 20 to 25 tons
being added to the atmosphere daily. Increasing acidity from rising levels of CO2 is
changing the ocean’s PH balance. Studies indicate that the shells and skeletons
possessed by everything from reef-building corals to mollusks and plankton begin to
dissolve within forty-eight hours of exposure to the acidity expected in the ocean
by 2050. Coral reefs will almost certainly disappear and, even more worrisome, so
will plankton. Phytoplankton absorb greenhouse gases, manufacture oxygen, and are
the primary producers of the marine food web. Mercury pollution enters the food web
via coal and chemical industry waste, oxidizes in the atmosphere, and settles to the
sea bottom. There it is consumed, delivering mercury to each subsequent link in the
food chain, until predators such as tuna or whales carry levels of mercury as much
as one million times that of the waters around them. The Gulf of Mexico has the
highest mercury levels ever recorded, with an average of ten tons of mercury coming
down the Mississippi River every year, and another ton added by offshore drilling.
Alfred Wegener Institute for Polar and Marine Research
Public release date: 4-Jan-2007
Contact: Dr. Ude Cieluch
Ude.Cieluch@awi.de
49-471-483-12007
How fish species suffer as a result of warmer waters
Ongoing global climate change causes changes in the species composition of marine
ecosystems, especially in shallow coastal oceans. This applies also to fish
populations. Previous studies demonstrating a link between global warming and
declining fish stocks were based entirely on statistical data. However, in order to
estimate future changes, it is essential to develop a deeper understanding of the
effect of water temperature on the biology of organisms under question. A new
investigation, just published in the scientific journal Science, reveals that a
warming induced deficiency in oxygen uptake and supply to tissues is the key factor
limiting the stock size of a fish species under heat stress.
Scientists of the Alfred Wegener Institute for Polar and Marine Research in
Bremerhaven investigated the relationship between seasonal water temperature and
population density using eelpout (Zoarces viviparus), a fish species from the
Southern North Sea. The goal of the study was to identify those physiological
processes exhibiting the most immediate response to warming in the field. Comparing
ecological field data with laboratory investigations of the eelpout’s physiology,
the authors were able, for the first time, to demonstrate a direct link between
temperature dependent oxygen limitation experienced by the eelpouts and warming
induced changes in their population density.
During evolution, animals have specialised on environmental conditions and are often
very limited in their tolerance to environmental change. In this context, fish
species from the North Sea which experience large seasonal temperature fluctuations,
are more tolerant to higher temperatures and display wider thermal windows than, for
instance, fishes from polar regions living at constant low temperatures. The latter
are able to grow and reproduce only within a very limited thermal tolerance window.
Investigations at the Alfred Wegener Institute show the key importance of oxygen
uptake and distribution – through respiration and blood circulation – in setting the
animals’ thermal tolerance range, in that these processes are optimised to only a
limited temperature window. With increasing temperature, the organism’s oxygen
supply is the first to deteriorate, followed by other biochemical stress responses.
Finally, oxygen supply fails entirely, leaving the organism to perish. These results
represent a significant step forward towards understanding the mechanisms involved
in climate-induced alterations in marine ecosystems.
The paper ‘Climate change affects marine fishes through the oxygen limitation of
thermal tolerance’ is published on January 5, 2007 in the scientific journal
Science.
###
Bremerhaven, 4th January 2007
NEWS RELEASE
OHIO STATE UNIVERSITY
MIDGES SEND UNDENIABLE MESSAGE: PLANET IS WARMING
COLUMBUS, Ohio – Small insects that inhabit some of the most remote parts of the
United States are sending a strong message about climate change. New research
suggests that changes in midge communities in some of these areas provide additional
evidence that the globe is indeed getting warmer.
Researchers created a history of changing midge communities for six remote mountain
lakes in the western United States. Midges, which resemble mosquitoes but usually
don’t bite, can live nearly anywhere in the world where there is fresh water.
The insect remains revealed a dramatic shift in the types of midges inhabiting these
lakes in the last three decades, said David Porinchu, the study’s lead author and an
assistant professor of geography at Ohio State University.
“Climate change has had an overriding influence on the composition of the midge
communities within these lakes,” he said. “The data suggest that the rate of warming
seen in the last two decades is greater than any other time in the previous
century.”
The data suggest that, starting around 25 years ago, warmer-water midges began to
edge out cooler-water midge species around these remote lakes.
“People would like to believe that these mountainous environments may be immune to
climate change, but these are some of the first areas to feel the impact of warmer
temperatures,” Porinchu said.
He and his colleagues presented their findings December 15 in San Francisco at the
annual meeting of the American Geophysical Union.
The researchers gathered sediment from six small lakes in the Great Basin of the
western United States – a vast watershed bounded roughly by the Sierra Nevada and
Rocky Mountain ranges. Since the lakes are accessible only by foot trail, the
researchers carried in an inflatable raft during the summer months in order to
collect sediment samples from the middle of the lakes. The lakes range from 8.2 feet
(2.5 meters) to 34.5 feet (10.5 meters) deep.
The scientists collected sediment in cylindrical plastic tubes, gathering several
samples from each lake. They didn’t need much sediment – just four inches (10 cm) of
lake-bottom residue can represent nearly 100 years’ worth of sedimentation, Porinchu
said.
“The amount of sediment that trickles out of the water column to the bottom of these
lakes every year is so low because these lakes are at such high elevations – few, if
any, trees grow at these elevations,” he said. “There just isn’t much material
entering the lakes.”
Once they were back in the laboratory, the researchers sliced the sediment cores
into thin slivers about 0.2 inches (0.5 cm) thick. Each sliver represents a five or
10-year span, Porinchu said. They calculated the age of single sediment layers by
using lead-210, an isotope of lead that decays at a constant rate and, therefore,
can serve as a chronological aid.
Using a microscope, the researchers then searched the sediment for larval remains of
the midges. Specifically, they were looking for larval head capsules, which are made
of a hard, semi-transparent material called chitin. These head capsules become
embedded in sediment once they are shed. Chitin, also a component of insect
exoskeletons and the shells of crustaceans, doesn’t readily degrade in the sediment
of these lakes.
The researchers determined the type of midges that lived in the lakes based on
specific variations in certain head capsule structures, such as differences in the
number, size, shape and orientation of teeth.
“In the upper layers of most of the sediment samples – those representing the last
25 to 30 years – we see head capsules from midges that normally thrive in slightly
warmer water temperatures,” Porinchu said. “And the cooler-water midges have nearly,
or completely, disappeared.”
Surface water temperatures in these lakes have risen anywhere from 0.5 to 1 degree
since the 1980s.
“Although that doesn’t seem to be a huge increase, just a slight fluctuation in
water temperatures can significantly affect the rate of egg and larval development,”
Porinchu said.
And the majority of midge species living in these six lakes in the last 30 years
thrive in temperatures ranging from 58.8 to 60 degrees F (14.9 to 15.6C), while
cooler-water midges prefer temperatures in the 57 to 58.1F (13.9 to 14.5C) range.
“Above-average surface water temperatures typified the late 20th century in all of
the lakes that we studied,” Porinchu said. “It’s clearly an indication that
something is happening that is already affecting aquatic ecosystems in these
fragile, high-elevation lakes.”
Porinchu conducted the study with researchers from the National University of
Ireland in Galway; the University of California, Los Angeles; the University of
Western Ontario in London, Ontario; and Middlebury College in Middlebury, Vt.
Contact: David Porinchu, (614) 247-2614; Porinchu.1@osu.edu
Written by Holly Wagner, (614) 292-8310; Wagner.235@osu.edu
—
EU: Climate change will transform the face of the continent
By Michael McCarthy and Stephen Castle
Europe, the richest and most fertile continent and the model for the modern world,
will be devastated by climate change, the European Union predicts today.
The ecosystems that have underpinned all European societies from Ancient Greece and
Rome to present-day Britain and France, and which helped European civilisation gain
global pre-eminence, will be disabled by remorselessly rising temperatures, EU
scientists forecast in a remarkable report which is as ominous as it is detailed.
Much of the continent’s age-old fertility, which gave the world the vine and the
olive and now produces mountains of grain and dairy products, will not survive the
climate change forecast for the coming century, the scientists say, and its wildlife
will be devastated.
Europe’s modern lifestyles, from summer package tours to winter skiing trips, will
go the same way, they say, as the Mediterranean becomes too hot for holidays and
snow and ice disappear from mountain ranges such as the Alps – with enormous
economic consequences. The social consequences will also be felt as heat-related
deaths rise and extreme weather events, such as storms and floods, become more
violent.
The report, stark and uncompromising, marks a step change in Europe’s own role in
pushing for international action to combat climate change, as it will be used in a
bid to commit the EU to ambitious new targets for cutting emissions of greenhouse
gases.
The European Commission wants to hold back the rise in global temperatures to 2C
above the pre-industrial level (at present, the level is 0.6C). To do that, it wants
member states to commit to cutting back emissions of carbon dioxide, the principal
greenhouse gas, to 30 per cent below 1990 levels by 2020, as long as other developed
countries agree to do the same.
Failing that, the EU would observe a unilateral target of a 20 per cent cut.
The Commission president, José Manuel Barroso, gave US President George Bush a
preview of the new policy during a visit to the White House this week.
The force of today’s report lies in its setting out of the scale of the
continent-wide threat to Europe’s “ecosystem services”.
That is a relatively new but powerful concept, which recognises essential elements
of civilized life – such as food, water, wood and fuel – which may generally be
taken for granted, are all ultimately dependent on the proper functioning of
ecosystems in the natural world. Historians have recognized that Europe was
particularly lucky in this respect from the start, compared to Africa or
pre-Columbian America – and this was a major reason for Europe’s rise to global
pre-eminence.
“Climate change will alter the supply of European ecosystem services over the next
century,” the report says. “While it will result in enhancement of some ecosystem
services, a large portion will be adversely impacted because of drought, reduced
soil fertility, fire, and other climate change-driven factors.
“Europe can expect a decline in arable land, a decline in Mediterranean forest
areas, a decline in the terrestrial carbon sink and soil fertility, and an increase
in the number of basins with water scarcity. It will increase the loss of
biodiversity.”
The report predicts there will be some European “winners” from climate change, at
least initially. In the north of the continent, agricultural yields will increase
with a lengthened growing season and a longer frost-free period. Tourism may become
more popular on the beaches of the North Sea and the Baltic as the Mediterranean
becomes too hot, and deaths and diseases related to winter cold will fall.
But the negative effects will far outweigh the advantages. Take tourism. The report
says “the zone with excellent weather conditions, currently located around the
Mediterranean (in particular for beach tourism) will shift towards the north”. And
it spells out the consequences.
“The annual migration of northern Europeans to the countries of the Mediterranean in
search of the traditional summer ‘sun, sand and sea’ holiday is the single largest
flow of tourists across the globe, accounting for one-sixth of all tourist trips in
2000. This large group of tourists, totalling about 100 million per annum, spends an
estimated ?100bn (£67bn) per year. Any climate-induced change in these flows of
tourists and money would have very large implications for the destinations
involved.”
While they are losing their tourists, the countries of the Med may also be losing
their agriculture. Crop yields may drop sharply as drought conditions, exacerbated
by more frequent forest fires, make farming ever more difficult. And that is not the
only threat to Europe’s food supplies. Some stocks of coldwater fish in areas such
as the North Sea will move northwards as the water warms.
There are many more direct threats, the report says. The cost of taking action to
cope with sea-level rise will run into billions of euros. Furthermore, “for the
coming decades, it is predicted the magnitude and frequency of extreme weather
events will increase, and floods will likely be more frequent and severe in many
areas across Europe.”
The number of people affected by severe flooding in the Upper Danube area is
projected to increase by 242,000 in a more extreme 3C temperature rise scenario, and
by 135,000 in the case of a 2.2C rise. The total cost of damage would rise from
?47.5bn to ?66bn in the event of a 3C increase.
Although fewer people would die of cold in the north, that would be more than offset
by increased mortality in the south. Under the more extreme scenario of a 3C
increase in 2071-2100 relative to 1961-1990, there would be 86,000 additional deaths.
—
NEW YORK TIMES
January 23, 2007
A Radical Step to Preserve a Species: Assisted Migration
http://www.nytimes.com/2007/01/23/science/23migrate.html?_r=1&oref=slogin
By CARL ZIMMER
The Bay checkerspot butterfly’s story is all too familiar. It was once a common
sight in the San Francisco Bay area, but development and invasive plants have wiped
out much of its grassland habitat.
Conservationists have tried to save the butterfly by saving the remaining patches
where it survives. But thanks to global warming, that may not be good enough.
Climate scientists expect that the planet will become warmer in the next century if
humans continue to produce greenhouse gases like carbon dioxide. The California
Climate Change Center projects the state’s average temperature will rise 2.6 to 10.8
degrees Fahrenheit. Warming is also expected to cause bigger swings in rainfall.
Studies on the Bay checkerspot butterfly suggest that this climate change will push
the insect to extinction. The plants it depends on for food will shift their growing
seasons, so that when the butterfly eggs hatch, the caterpillars have little to eat.
Many other species may face a similar threat, and conservation biologists are
beginning to confront the question of how to respond. The solution they prefer would
be to halt global warming. But they know they may need to prepare for the worst.
One of the most radical strategies they are considering is known as assisted
migration. Biologists would pick a species up and move it hundreds of miles to a
cooler place.
Assisted migration triggers strong, mixed feelings from conservation biologists.
They recognize that such a procedure would be plagued by uncertainties and risk. And
yet it may be the only way to save some of the world’s biodiversity.
“Some days I think this is absolutely, positively something that has to be done,”
said Dr. Jessica Hellmann of the University of Notre Dame. “And other days I think
it’s a terrible idea.”
Conservation biologists are talking seriously about assisted migration because the
effects of climate change are already becoming clear. The average temperature of the
planet is 1.6 degrees Fahrenheit higher than it was in 1880. Dr. Camille Parmesan, a
biologist at the University of Texas, reviewed hundreds of studies on the ecological
effects of climate change this month in the journal Annual Review of Ecology,
Evolution, and Systematics. Many plant species are now budding earlier in the spring. Animals migrate earlier as well. And the ranges of many species are shifting to higher latitudes, as they track the climate that suits them best.
This is hardly the first time that species have moved in response to
climate change. For over two million years, the planet has swung between ice ages
and warm periods, causing some species to shift their ranges hundreds of miles. But
the current bout of warming may be different. The earth was already relatively warm
when it began. “These species haven’t seen an earth as warm as this one’s going to be in
a long,long time,” said Dr. Mark Schwartz, a conservation biologist at the University of
California, Davis.
It’s also going to be more difficult for some species to move, Dr. Schwartz added.
When the planet warmed at the end of past ice ages, retreating glaciers left behind empty landscapes. Today’s species will face an obstacle course made of cities, farms and other human settlements.
Animals and plants will also have to move quickly. If a species cannot keep up with
the shifting climate, its range will shrink. Species that are already limited to
small ranges may not be able to survive the loss.
In 2004, an international team of scientists estimated that 15 percent to 37 percent
of species would become extinct by 2050 because of global warming. “We need to limit
climate change or we wind up with a lot of species in trouble, possibly extinct,”
said Dr. Lee Hannah, a co-author of the paper and chief climate change biologist at
the Center for Applied Biodiversity Science at Conservation International.
Some scientists have questioned that study’s methods. Dr. Schwartz calls it an
overestimate. Nevertheless, Dr. Schwartz said that more conservative estimates would
still represent “a serious extinction.”
Many conservation biologists believe that conventional strategies may
help combat extinctions from global warming. Bigger preserves, and corridors
connecting them, could give species more room to move.
Conservation biologists have also been talking informally about assisted migration.
The idea builds on past efforts to save endangered species by moving them to parts
of their former ranges. The gray wolf, for example, has been translocated from
Canada to parts of the western United States with great success.
When Dr. Jason McLachlan, a Notre Dame biologist, gives talks on global warming and
extinction, “someone will say, ‘It’s not a problem, since we can just FedEx them to
anywhere they need to go,'” he said.
No government or conservation group has yet begun an assisted migration for global
warming. But discussions have started. “We’re thinking about these issues,” said Dr.
Patrick Gonzalez, a climate scientist at the Nature Conservancy.
The conservancy is exploring many different ways to combat extinctions from global
warming, and Dr. Gonzalez says that assisted migration “could certainly be one of
the options.” For now, the conservancy has no official policy on assisted migration.
As Dr. McLachlan began hearing about assisted migration more often, he became
concerned that conservation biologists were not weighing it scientifically. He
joined with Dr. Schwartz and Dr. Hellmann to lay out the terms of the debate in a
paper to be published in the journal Conservation Biology.
Dr. McLachlan and his colleagues argue that assisted migration may indeed turn out
to be the only way to save some species. But biologists need to answer many
questions before they can do it safely and effectively.
The first question would be which species to move. If tens of thousands are facing
extinction, it will probably be impossible to save them all. Conservation biologists
will have to make the painful decision about which species to try to save. Some
species threatened by climate change, including polar bears and other animals
adapted to very cold climates, may have nowhere to go.
The next challenge will be to decide where to take those species. Conservation
biologists will have to identify regions where species can survive in a warmer
climate. But to make that prediction, scientists need to know how climate controls
the range of species today. In many countries, including the United States, that
information is lacking.
“We don’t even know where species are now,” Dr. McLachlan said.
Simply moving a species is no guarantee it will be saved, of course. Many species depend intimately on other species for their survival. If conservation biologists move the Bay checkerspot butterfly hundreds of miles north to Washington, for example, it may not be able to feed on the plants there. Conservation biologists may have to move entire networks of species, and it may be hard to know where to
draw the line.
Assisted migration is plagued not only with uncertain prospects of success, but
potential risks as well. A transplanted species would, in essence, be an invasive
one. And it might thrive so well that it would start to harm other species. Invasive
species are among the biggest threats to biodiversity in some parts of the world.
Many were accidentally introduced but some were intentionally moved with great
confidence that they would do no harm. Cane toads were introduced in Australia to
destroy pests on sugar plantations, and they proceeded to wipe out much of the continent’s wildlife.
“If you’re trying to protect a community of species, you’re not going to want
someone to introduce some tree from Florida,” Dr. Hellmann said. “But if you’re
someone watching that tree go extinct, you’re going to want to do it.”
Dr. Hellmann and her colleagues do not endorse or condemn assisted migration in their new paper. Instead, they call for other conservation biologists to join in a debate. They hope to organize a meeting this summer to have experts share their ideas.
“There really needs to be a clear conversation about this, so that we can lay all
the chips on the table,” Dr. Schwartz said.
Other experts on global warming and extinctions praised the new paper for framing
the assisted migration debate. “It’s certainly on everybody’s mind, and people are
discussing it quite a lot,” Dr. Hannah said. “This paper’s a breakthrough in that
sense.”
Dr. Hannah for one is leery of moving species around. “I’m not a huge fan of assisted migration, but there’s no question we’ll have to get into it to some degree,” he said. “We want to see it as a measure of last resort, and get into it as
little as possible.”
It is possible that conservation biologists may reject assisted migration in favor
of other strategies, Dr. McLachlan said. But the hard questions it raises will not go away. As species shift their ranges, some of them will push into preserves that are refuges for endangered species.
“Even if we don’t move anything, they’re going to be moving,” Dr. McLachlan said.
“Do we eradicate them? All of these issues are still relevant.”
—