Category: RT Newswire

EurekAlert! AAAS

NASA/Goddard Space Flight Center
Public release date: 15-Nov-2007

Contact: Lynn Chandler
lynn.chandler-1@nasa.gov
301-286-2806

Forests damaged by Hurricane Katrina become major carbon source

With the help of NASA satellite data, a research team has estimated that Hurricane Katrina killed or severely damaged 320 million large trees in Gulf Coast forests, which weakened the role the forests play in storing carbon from the atmosphere. The damage has led to these forests releasing large quantities of carbon dioxide to the atmosphere.

The August 2005 hurricane affected five million acres of forest across Mississippi, Louisiana and Alabama, with damage ranging from downed trees, snapped trunks and broken limbs to stripped leaves.

Young growing forests play a vital role in removing carbon dioxide, a greenhouse gas, from the atmosphere by photosynthesis, and are thus important in slowing a warming climate. An event that kills a great number of trees can temporarily reduce photosynthesis, the process by which carbon is stored in plants. More importantly, all the dead wood will be consumed by decomposers, resulting in a large carbon dioxide release to the atmosphere as the ecosystem exhales it as forest waste product. The team’s findings were published Nov. 15 in the journal Science.

“The loss of so many trees will cause these forests to be a net source of carbon dioxide to the atmosphere for years to come,” said the study’s lead author Jeffrey Chambers, a biologist at Tulane University in New Orleans, La. “If, as many believe, a warming climate causes a rise in the intensity of extreme events like Hurricane Katrina, we’re likely to see an increase in tree mortality, resulting in an elevated release of carbon by impacted forest ecosystems.”

Young forests are valued as carbon sinks, which remove carbon dioxide from the atmosphere and store it in growing vegetation and soils. In the aftermath of a storm as intense as Katrina, vegetation killed by the storm decomposes over time, reversing the carbon storage process, making the forest a carbon source.

“The carbon cycle is intimately linked to just about everything we do, from energy use to food and timber production and consumption,” said Chambers. “As more and more carbon is released to the atmosphere by human activities, the climate warms, triggering an intensification of the global water cycle that produces more powerful storms, leading to destruction of more trees, which then act to amplify climate warming.”

Chambers and colleagues from the University of New Hampshire in Durham, N.H., studied Landsat 5 satellite data captured before and after Hurricane Katrina to pull together a reliable field sampling of tree deaths across the entire range of forests affected by Katrina. They found that some forests were heavily damaged while others like the cypress-tupelo swamp forests fared remarkably well.

The NASA-built Landsat 5, part of the Landsat series of Earth-observing satellites, takes detailed images of the Earth’s surface. Chambers combined results from the Landsat image sampling with data from the Moderate Resolution Imaging Spectroradiometer instrument on NASA’s Terra satellite to estimate the size of the entire forested area affected by Katrina. The instrument can detect minute changes in the color spectrum on the land below, enabling it to measure differences in the percentage of live and dead vegetation. This helps researchers improve their estimates of changes in carbon storage and improves their ability to track the location of carbon sinks and sources.

The field samples and satellite images, along with results from computer models that simulate the kind of vegetation and other traits that make up the forests, were used to measure the total tree loss the hurricane inflicted. The scientists then calculated total carbon losses to be equivalent to 60-100 percent of the net annual carbon sink in U.S. forest trees.

“It is surprising to learn that one extreme event can release nearly as much carbon to the atmosphere as all U.S. forests can store in an average year,” said Diane Wickland, manager of the Terrestrial Ecology Program at NASA Headquarters in Washington. “Satellite data enabled Chambers’ research team to pin down the extent of tree damage so that we now know how these kinds of severe storms affect the carbon cycle and our atmosphere. Satellite technology has really proven its worth in helping researchers like Chambers assess important changes in our planet’s carbon cycle.”

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http://www.nasa.gov/mission_pages/hurricanes/archives/2007/katrina_carbon.html

Written by:
Gretchen Cook-Anderson
Goddard Space Flight Center
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13/11/2007

Primary rain forest is irreplaceable

As world leaders prepare to discuss conservation-friendly carbon credits in Bali and a regional initiative threatens a new wave of deforestation in the South American tropics, new research from the University of East Anglia and Brazil’s Goeldi Museum highlights once again the irreplaceable importance of primary rain forest.

Working in the north-eastern Brazilian Amazon the international team of scientists undertook the single-largest assessment of the biodiversity conservation value of primary, secondary and plantation forests ever conducted in the humid tropics. The study was partly funded by the UK Government’s Darwin Initiative and their findings are reported in the latest edition of the Proceedings of the National Academy of Sciences (PNAS).

Over an area larger than Wales, the UEA and museum researchers surveyed five primary rain forest sites, five areas of natural secondary forest and five areas planted with fast-growing exotic trees (Eucalyptus), to evaluate patterns of biodiversity.

Following an intensive effort of more than 20,000 scientist hours in the field and laboratory, they collected data on the distribution of 15 different groups of animals (vertebrates and invertebrates) and woody plants, including well-studied groups such as monkeys, butterflies and amphibians and also more obscure species such as fruit flies, orchid bees and grasshoppers.

“We know that different species often exhibit different responses to deforestation and so we sought to understand the consequences of land-use change for as many species as possible,” said Dr Jos Barlow, a former post-doctoral researcher at UEA.

At least a quarter of all species were never found outside native primary forest habitat – and the team acknowledges that this is an underestimate. “Our study should be seen as a best-case scenario, as all our forests were relatively close to large areas of primary forests, providing ample sources for recolonisation,” said Dr Barlow.

“Many plantations and regenerating forests along the deforestation frontiers in South America and south-east Asia are much further from primary forests, and wildlife may be unable to recolonise in these areas.

“Furthermore, the percentage of species restricted to primary forest habitat was much higher (40-60%) for groups such as birds and trees, where we were able to sample the canopy species as well as those that live in the forest under-storey.”

These results clearly demonstrate the unique value of undisturbed tropical forests for wildlife conservation. However, they also show that secondary forests and plantations offer some wildlife benefits and can host many species that would be unable to survive in intensive agricultural landscapes such as cattle ranching or soybean plantations.

“Although the protection of large areas of primary forest is vital for native biodiversity conservation, reforestation projects can play an important supplementary role in efforts to boost population sizes of forest species and manage vast working landscapes that have already been heavily modified by human-use” explained Dr Carlos Peres, who leads the UEA team.

But, when carbon-credits from Reduced Emissions from Deforestation and Degradation (REDDS) are tabled for the first time at the Bali meeting next month, decision makers should beware of seeing fast-growing exotics such as eucalyptus as a carbon sink solution to the world’s emissions problems. If agreed upon by world leaders REDDs offer an extraordinary opportunity to generate funds to support the long-term protection of large areas of intact forest habitat

Pristine forests are home to over half of all terrestrial species in the world and their loss would impoverish the planet. Far better to save primary forest from deforestation in the first place,” added Dr Peres. “That way we maximize both the biodiversity and carbon value of whole landscapes.”

For years now, skeptics have tried to blame all global heating on variations in solar output. And, yes, fluctuations of solar output can make a real difference.

But the real story here is that we’ve made increases in solar output more dangerous than ever before because, now, they will come in addition to heating that we’ve forced upon ourselves by our consumption of fossil fuels and forests.

Lance Olsen

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University of Colorado at Boulder
Public release date: 13-Nov-2007

Satellite shows regional variation in warming from sun during solar cycle

SORCE satellite.

A NASA satellite designed, built and controlled by the University of Colorado at Boulder is expected to help scientists resolve wide-ranging predictions about the coming solar cycle peak in 2012 and its influence on Earth’s warming climate, according to the chief scientist on the project.

Senior Research Associate Tom Woods of CU-Boulder’s Laboratory for Atmospheric and Space Physics said the brightening of the sun as it approaches its next solar cycle maximum will have regional climatic impacts on Earth. While some scientists predict the next solar cycle–expected to start in 2008–will be significantly weaker than the present one, others are forecasting an increase of up to 40 percent in the sun’s activity, said Woods.

Woods is the principal investigator on NASA’s $88 million Solar Radiation and Climate Experiment, or SORCE, mission, launched in 2003 to study how and why variations in the sun affect Earth’s atmosphere and climate. In August, NASA extended the SORCE mission through 2012. The extension provides roughly $18 million to LASP, which controls SORCE from campus by uploading commands and downloading data three times daily to the Space Technology Building in the CU Research Park.

Solar cycles, which span an average of 11 years, are driven by the amount and size of sunspots present on the sun’s surface, which modulate brightness from the X-ray to infrared portion of the electromagnetic spectrum. The current solar cycle peaked in 2002.

Solar activity alters interactions between Earth’s surface and its atmosphere, which drive global circulation patterns, said Woods. While warming on Earth from increased solar brightness is modest compared to the natural effects of volcanic eruptions, cyclical weather patterns like El Nino or human emissions of greenhouse gases, regional temperature changes can vary by a factor of eight.

During the most recent solar maximum, for example, the global mean temperature rise on Earth due to solar-brightness increases was only about 0.2 degrees Fahrenheit, said Woods. But parts of the central United States warmed by 0.7 degrees F, and a region off the coast of California even cooled slightly. A paper on the coming decade of solar activity by Woods and Judith Lean of the Naval Research Laboratory in Washington, D.C., was published online Oct. 30 in the scientific newsletter, Eos.

“It was very important to the climate change community that SORCE was extended, because it allows us to continue charting the solar irradiance record in a number of wavelengths without interruption,” Woods said. “Even relatively small changes in solar output can significantly affect Earth because of the amplifying affect in how the atmosphere responds to solar changes.”

With mounting concern over the alteration of Earth’s surface and atmosphere by humans, it is increasingly important to understand natural “forcings” on the sun-Earth system that impact both climate and space weather, said Woods. Such natural forcing includes heat from the sun’s radiation that causes saltwater and freshwater evaporation and drives Earth’s water cycle.

Increases in UV radiation from the sun also heat up the stratosphere–located from 10 miles to 30 miles above Earth–which can cause significant changes in atmospheric circulation patterns over the planet, affecting Earth’s weather and climate, he said. “We will never fully understand the human impact on Earth and its atmosphere unless we first establish the natural effects of solar variability.”

SORCE also is helping scientists better understand violent space weather episodes triggered by solar flares and coronal mass ejections that affect the upper atmosphere and are more prevalent in solar maximum and declining solar cycle phases, said Woods. The severe “Halloween Storms” in October and November 2003 disrupted GPS navigation and communications, causing extensive and costly rerouting of commercial “over-the-poles” jet flights to lower latitudes, he said.

Woods also is the principal investigator on a $30 million instrument known as the Extreme Ultraviolet Variability Experiment, or EVE, one of three solar instruments slated for launch on NASA’s Solar Dynamic Observatory in December 2008. Designed and built at LASP and delivered to NASA’s Goddard Space Flight Center in Maryland last September, EVE will measure precise changes in the sun’s UV brightness, providing space weather forecasters with early warnings of potential communications and navigation outages.

About one-third of the annual SORCE budget goes for commanding and controlling the satellite, roughly one-third for producing public data sets and one-third for analyzing how and why the sun is changing, he said. “CU-Boulder students are our lifeblood,” said Woods. “They are involved in all aspects of the SORCE mission, from uploading commands to the spacecraft to analyzing data.”

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A podcast on SORCE featuring Woods can be accessed on the Web at:

http://www.colorado.edu/news/podcasts/.

For more information on SORCE, visit the Web at:

http://lasp.colorado.edu/sorce/news_letter.html.
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Scientific American
October 26, 2007

The World Is Not Enough for Humans

Humanity’s environmental impact has reached an unprecedented scope,
and it’s getting worse.

Since 1987 annual emissions of carbon dioxide-the leading greenhouse
gas warming the globe-have risen by a third, global fishing yields
have declined by 10.6 million metric tons and the amount of land
required to sustain humanity has swelled to more than 54 acres (22
hectares) per person. Yet, Earth can provide only roughly 39 acres
(15 hectares) for every person living today, according to the United
Nation’s Environmental Program’s (UNEP) Global Environment Outlook,
released this week. “There are no major issues,” the report’s authors
write of the period since their first report in 1987, “for which the
foreseeable trends are favorable.”

Despite some successes-such as the Montreal Protocol’s 95 percent
reduction in chemicals that damage the atmosphere’s ozone layer and a
rise in protected reserves of habitat to cover 12 percent of the
planet-humanity’s impact continues to grow. For example:

Biodiversity-The planet is in the grips of the sixth great extinction
in its 4.5-billion-year history, this one largely man-made. Species
are becoming extinct 100 times faster than the average rate in the
fossil record. More than 30 percent of amphibians, 12 percent of
birds and 23 percent of our own class, mammals, are threatened.

Climate-Average temperatures have climbed 1.4 degrees Fahrenheit
(0.76 degree Celsius) over the past century and could increase as
much as 8.1 degrees F (4.5 degrees C) over the next unless “drastic”
steps are taken to reduce greenhouse gas emissions from, primarily,
burning fossil fuels. Developed countries will need to reduce this
globe-warming pollution by 60 to 80 percent by mid-century to stave
off dire consequences, the report warns. “Fundamental changes in
social and economic structures, including lifestyle changes, are
crucial if rapid progress is to be achieved.”

Food-The amount of food grown per acre has reached one metric ton,
but such increasing intensity is also driving rapid desertification
of formerly arable land as well as reliance on chemical pesticides
and fertilizers. In fact, four billion out of the world’s 6.5 billion
people could not get enough food to eat without such fertilization.
Continuing population growth paired with a shift toward eating more
meat leads the UNEP to predict that food demand may more than triple.

Water-One in 10 of the world’s major rivers, including the Colorado
and the Rio Grande in the U.S., fail to reach the sea for at least
part of the year, due to demand for water. And that demand is rising;
by 2025, the report predicts, demand for fresh water will rise by 50
percent in the developing world and 18 percent in industrialized
countries. At the same time, human activity is polluting existing
fresh waters with everything from fertilizer runoff to
pharmaceuticals and climate change is shrinking the glaciers that
provide drinking water for nearly one third of humanity. “The
escalating burden of water demand,” the report says, “will become
intolerable in water-scarce countries.”

The authors-388 scientists reviewed by roughly 1,000 of their
peers-view the report as “an urgent call for action” and decry the
“woefully inadequate” global response to problems such as climate
change. “The amount of resources needed to sustain [humanity] exceeds
what is available,” the report declares.

“The systematic destruction of the earth’s natural and nature-based
resources has reached a point where the economic viability of
economies is being challenged,” Achim Steiner, UNEP’s executive
director, said in a statement. “The bill we hand our children may
prove impossible to pay.”

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