We study interactions between atmospheric chemistry and the climate system. Our goal is to understand the impacts of the short-lived climate forcers on air quality and climate in past, present and future worlds. The main tools are Earth system modeling and multiple observational datasets, especially from satellites and flux towers. Current research areas include: plant volatile organic carbon emissions, wildfire emissions, and human land use change and land-based climate mitigation impacts on air quality and climate. Our policy-relevant research projects provide results that support effective environmental management and decision-making.