Global Warming Moves Costa Rica Coffee Land Higher
Tue Jun 24, 2008 7:22pm EDT By John McPhaul
SAN JOSE, Costa Rica (Reuters) – Costa Rican coffee farmers are facing threats from climate change but the rising temperatures are also expanding high-altitude regions where the country’s most prized beans are grown.
Human emissions of greenhouse gases could cause the earth’s surface temperature to rise anywhere between one and six degrees Celsius (1.8 and 10.8 degrees Fahrenheit) over the next 100 years, according to the United Nations, forcing growers of all crops to adapt to new weather conditions.
In Costa Rica, the temperature increases may help transform mountainous land that was once too chilly for delicate coffee trees into prime coffee-planting territory.
The strictly hard-bean Arabica coffee sought by specialty roasters is only found at high altitudes, so the shift could mean more opportunities for a country already known for its quality coffee.
“We can now plant at 2,000 meters (6,562 feet). We didn’t plant there before,” said Daniel Urena, an agronomist for the Coopedota coffee cooperative, which sells its high-altitude coffee to buyers such as Starbucks Corp.
Urena said the cooperative’s coffee plants traditionally have not survived above 1,800 meters (5,906 feet).
DRY SPELLS, NEW PESTS
But while farmers in Costa Rica’s highlands maybe able to develop into new areas, climate change could bring blight to the crop with unseasonable dry spells, unusual cold snaps and more difficulties growing coffee at lower elevations.
A recent U.N. study in Uganda found an increase of just two degrees Celsius (3.6 degrees Fahrenheit) would drastically cut back the land area suitable for coffee.
In the coffee-growing regions that survive, global warming could leave stressed coffee trees susceptible to new diseases and some coffee pests thriving in the warmer weather.
“Increases in the frequency of dry cycles that reduce the effect of cold on plants could favor the proliferation of fungus like the leaf rust coffee fungus,” said Patricia Ramirez, a scientist working for inter-governmental Central American Integration System.
The rust infects mainly leaves, but also attacks young fruit and buds, and hit Brazil’s coffee crop in 1970.
Strong winds that unexpectedly affected production in Guatemala and a severe drought in Brazil — the world’s leading coffee producer — last year are examples of how global climate change can damage crops and reduce yields, said Jorge Ramirez, head of the Costa Rican Coffee Institute’s research center.
He said growers can take measures to mitigate the effects of climate change by planting more shade trees in coffee fields to protect cherries from stronger-than-usual rains or creating protective windbreaks around farms with fast-growing trees.
“We have to educate farmers to use (these methods) more,” he said.
(Additional reporting and writing by Mica Rosenberg; Editing by Christian Wiessner)
Climate change to create “plant refugees”
Wed Jun 25, 2008 1:06am EDT By Julie Steenhuysen
CHICAGO (Reuters) – Climate change may turn many of California’s native plants into “plant refugees” in the next century as they seek more suitable habitats, U.S. researchers said on Tuesday.
They said changes in climate arising from heat-trapping greenhouse gasses would affect hundreds of native plant species including the state’s famed Coast Redwoods, which are among the tallest trees on earth.
“Many species may have to move to cooler areas in order to survive,” climate scientist Katharine Hayhoe of Texas Tech University, one of a team of researchers whose work appears in the Public Library of Science journal PLoS ONE, said in a statement.
“In some of these cases, for example when a plant grows near the top of a mountain, there’s nowhere to go,” Hayhoe said.
The researchers tracked 5,500 plants native to California and used computer models to predict how climate change would affect their distribution.
They concluded that a warming climate and changes in rainfall would force many plants to range north or to higher elevations or possibly become extinct in the next 100 years.
“We found the extent of climate change impact can be very broad,” Hayhoe said in a telephone interview.
“In two-thirds of the 5,500 plants we studied, the area where you can find them shrank by 80 percent,” Hayhoe said.
She said about 40 percent of the plants they studied exist only in California. “Preserving them is very important.”
They predict Coast Redwoods would be forced farther north, while California oaks might disappear from central California in favor of the Klamath Mountains along the California-Oregon border.
The researchers used two different climate models that predict changes in temperature and rainfall through 2100 to make their projections — one that assumes higher and another that assumes lower greenhouse gas emissions.
“In nearly every scenario we explored, biodiversity suffers — especially if the flora can’t disperse fast enough to keep pace with climate change,” Scott Loarie, a Ph.D candidate at Duke University, said in a statement.
What the models did suggest, however, is that reducing greenhouse gases would have a significant impact on native species, Hayhoe said. And it pointed to steps conservationists could take to preserve California’s native species.
“We were able to identify some specific locations that are refuges where these plants would be able to survive,” Hayhoe said. “That helps us to plan ahead to protect these important plant species.”
Brent Mishler of the University of California, Berkeley said conservationists will need to keep in mind what plants are at risk of becoming plant refugees. “Planning for refugees will become a new but important concept for natural reserves to think about,” he said in a statement.
Maps showing the impact of climate change on California’s plant species are available here . The article can be downloaded from the PLoS ONE Web site here .
(Editing by Maggie Fox and Todd Eastham)