The role of soils and biogeochemistry in the Climate and Earth System

Soils play a central role throughout the climate system, through regulating the atmospheric abundance of key trace gases including, carbon dioxide, methane and nitrous oxide exchange, tropospheric and stratospheric ozone and some halogens, i.e. methyl bromide and methyl flouride. The Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) concluded “warming is unequivocal” based on many lines of observational evidence. Humans are forcing the climate system in a new way with the release of carbon dioxide to the atmosphere by fossil fuel burning. Atmospheric carbon dioxide concentrations have not been this high in more than a half a million years. The AR4 was the first Earth System IPCC report because of the inclusion of a fully interactive carbon cycle and was the first Working Group 1 report to address the changing global nitrogen cycle. Soils and their sustained productivity remain a critical ethical discussion for the future of Earth System modeling and for the future of life on our Earth.