Process-scale investigation of the exchange of greenhouse gases and aerosol precursors with terrestrial surfaces is needed to improve mechanistic understanding of biogeochemical processes and the ability to predict responses of the Earth system to nutrient supply, land use changes, and climatic perturbations. Soil microbiological processes control atmosphere-surface exchange of greenhouse gases, like nitrous oxide and methane, and also aerosol precursors, like nitric oxide and ammonia. Aerosol precursors react in the atmosphere to form fine aerosol that influence direct and indirect radiative forcing of climate. The exchange of CO2 with vegetation and forest emissions of terpenes that are precursors to organic aerosols depend on the atmospheric supply of nitrogen because the carbon and nitrogen cycles are inextricably linked by the composition of living phytomass. Research challenges and opportunities that lie ahead in understanding the role of atmosphere-biosphere exchange in climate change will be discussed.