From introduction: Wildfire is a majoar natural disaster in the United States. In 2002, for example, tens of thousands of wildfires occurred that consumed nearly seven million acres of forest and other land cover (NIFC, 2003). Wildfires contribute to increasing atmospheric CO2 concentration and, therefore, intensifying the greenhouse effect. The perturbation of atmospheric chemistry induced by global biomass burning is comparable in magnitude to the effect of fossil fuel burning (Lindesay et al., 1996). Climate is a major environmental factor for wildfire frequency and intensity (Pyne et al., 1996). Thus, the trends in CO2 emissions from wildfire are largely determined by future climate change. A number of climate models (e.g., Mitchell et al. 1995) have projected significant changes in the U.S. regional climate in response to the greenhouse effect, suggesting a great impact on future wildfire emissions of CO2. This study seeks to understand the role of wildfire in the carbon cycle and possible disturbance due to the greenhouse effect over the U.S.