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Scientists and NGOs: Deforestation and Degradation Responsible for Approximately 15 Percent of Global Warming Emissions

Nov 06, 2009 - Union of Concerned Scientists

As Fossil Fuel Emissions Rise, Deforestation Makes up Smaller Percent, Still Significant Problem

BARCELONA, SPAIN (November 6, 2009) — Scientists and non-governmental organizations at the United Nations climate negotiations commented today on the percentage of global warming emissions that is due to tropical deforestation, in light of a new analysis published earlier this week in Nature Geoscience. The group, which included most of the leading experts on deforestation emissions, released the following statement:

'The new paper, other papers and Intergovernmental Panel on Climate Change reports published in the last few years lead us to conclude that the percentage of global carbon dioxide (CO2) emissions from deforestation and forest degradation is less than the commonly used figure of 'about 20 percent.' The best current estimate would be about 15 percent if peat degradation is included. Given the uncertainties involved one can not rely on estimates to the nearest 1 percent.

The change in the estimate is due to several factors, including increases in fossil fuel emissions, as well as revision of the estimates of deforestation emissions, due to new data and scientific analyses. The change is not due to a decrease in deforestation since the 1990s, and in fact the analyses agree that global deforestation in the early 2000s has been similar to that in the 1990s. So, this new estimate is not a sign of progress.

This figure includes deforestation, forest degradation, and peat emissions from deforestation and degradation (including later decomposition and fires in peat from previously deforested areas).

These changes and the new paper are typical of how science advances, and reflect our improved ability to measure the emissions due to deforestation. They reinforce the point that reducing emissions from tropical deforestation is critical to slowing global warming. These emissions are comparable to the emissions of all of the European Union, and are greater than those of all cars, trucks, planes, ships and trains worldwide.

Reducing tropical forest emissions remains a relatively cost-effective option to reduce emissions. We would highlight some important lines from the new paper:

'…reducing fossil fuel emissions remains the key element for stabilizing atmospheric CO2 concentrations. Nevertheless, efforts to mitigate emissions from tropical forests and peatlands, and maintain existing terrestrial carbon stocks, remain critical….'"

The Union of Concerned Scientists is the leading U.S. science-based nonprofit organization working for a healthy environment and a safer world. Founded in 1969, UCS is headquartered in Cambridge, Massachusetts, and also has offices in Berkeley, Chicago and Washington, D.C.