Carbon Offsets Not Good Enough, Says Report

Nov. 13, 2007 -- Only about a third of the climate-damaging carbon dioxide released into the atmosphere in North America is offset by carbon-removing activities, a government report said Tuesday.

Currently, North America produces more than one-fourth of the carbon dioxide released worldwide by burning fossil fuels and other activities, the U.S. Climate Change Science program said in the report.

The report comes as top climate researchers from around the world meet in Spain to work on a new analysis on climate change, an increasing concern to scientists and policymakers worried about warming temperatures.

According to the new U.S. study, North America released 1,856 million metric tons of carbon into the air in 2003 -- 85 percent from the United States, 9 percent from Canada and 6 percent from Mexico.

At the same time, growing vegetation and other sources took in about 500 million metric tons of carbon.

This is the first net carbon report for the region, said Tony King, lead researcher on the report and chief scientist at Oak Ridge National Laboratory.

The amount of carbon taken up by North America had not been closely studied, and some reports even suggested that enough was being absorbed to balance emissions, King said.

It is now clear that is not the case, and North America is contributing to the worldwide increase in carbon dioxide in the air, he said.

In addition, King said, the main source of carbon dioxide absorption is regrowth of forests that were cut for agriculture or timber about 150 years ago. Because this regrowth is relatively new it is taking in carbon rapidly, but that rate will decline as the forests age, he said.

"Actions to reduce fossil fuel emissions are going to be required if we are interested in mitigating the effects" of climate change, added Lisa Dilling of the University of Colorado, co-lead author of the report.