A new report has warned that climate change may make forests release huge quantities of carbon and create a situation in which they do more to accelerate warming than to slow it down.
The report, titled "Adaptation of Forests and People to Climate Change - A Global Assessment", will be formally presented at the next session of the United Nations Forum on Forests (UNFF) taking place 20 April-1 May 2009 at the UN Headquarters in New York City.
Authored by 35 of the world's top forestry scientists, it provides the first global assessment to date of the ability of forests to adapt to climate change and is expected to play a key role in next week's UNFF discussions.
The report presents the state of scientific knowledge regarding the current and projected future impacts of climate change on forests and people along with options for adaptation.
"We normally think of forests as putting the brakes on global warming, but in fact over the next few decades, damage induced by climate change could cause forests to release huge quantities of carbon and create a situation in which they do more to accelerate warming than to slow it down," said Risto Seppala, who chaired the expert panel that produced the report.
Scientists hope the new assessment will inform international climate change negotiations, set to resume in December in Copenhagen, where forest-related deliberations thus far have focused mainly on carbon emissions from deforestation.
The analysis shows that officials also must consider how the world's forests are likely to suffer-and perhaps severely-as the earth gets warmer.
While deforestation is responsible for about 20 percent of greenhouse gases, overall, forests currently absorb more carbon than they emit.
The trees and soils of the world's forests are capturing and storing more than a quarter of the world's carbon emissions.
The problem, according to scientists, is that this critical carbon-regulating service could be lost entirely if the earth heats up 2.5 degrees Celsius or more relative to pre-industrial levels, which is expected to occur if emissions are not substantially reduced.
The study notes that the higher temperatures, along with the prolonged droughts, more intense pest invasions, and other environmental stresses that could accompany climate change, would lead to considerable forest destruction and degradation.
This could create a dangerous feedback loop in which damage to forests from climate change significantly increases global carbon emissions, which then exacerbate the greenhouse effect.