How Do Emissions Over Global Forests Impact Climate?

With increasing global temperatures, wildfires have become more intense and frequent, emitting significant amounts of trace gases and aerosols. However, there is still uncertainty about how these increasing emissions will impact local and global climate systems. While most studies have focused on how climate change affects wildfire frequency and intensity or how to predict wildfire occurrences, limited research exists on how wildfire-related emissions influence climate. An open question remains regarding which forest regions have the greatest impact or whether these impacts are similar across different forests.

To address these gaps, we used the Community Earth System Model version 2 (CESM2) to conduct a series of comprehensive numerical experiments. The experimental design included a baseline control simulation to represent current climate conditions without additional emissions from forests. Sensitivity experiments were performed by doubling emissions across all global forests and separately over the Amazon and Boreal forests to evaluate their effects on temperature, precipitation, atmospheric circulation, radiative balance, and chemical interactions in the atmosphere. Additional targeted simulations were conducted to isolate the roles of black carbon (BC), a warming aerosol, and sulfates, a cooling aerosol, to determine their individual and combined impacts on cloud formation, albedo, radiation, and atmospheric chemistry.

Future research should aim to refine the understanding of these processes through more comprehensive modeling and observational studies, focusing on different regions and timescales to better capture the variability and uncertainties associated with wildfire impacts.