Methane (CH4) is the second most important greenhouse gas that humans directly influence, carbon dioxide (CO2) being first. Concerns about methane’s role in abrupt climate change stem primarily from (1) the large quantities of methane stored as solid methane hydrate on the sea floor and to a lesser degree in terrestrial sediments, and the possibility that these reservoirs could become unstable in the face of future global warming, and (2) the possibility of large-scale conversion of frozen soil in the high- latitude Northern Hemisphere to methane producing wetland, due to accelerated warming at high latitudes. This chapter summarizes the current state of knowledge about these reservoirs and their potential for forcing abrupt climate change.
U.S. Climate Change Science Program and the Subcommittee on Global Change Research
Brook E, Archer D, Dlugokencky E, Frolking S, Lawrence D. 2008. Potential for abrupt changes in atmospheric methane, pp. 163-201 in U.S. Climate Change Science Program Synthesis and Assessment Product 3.4: Abrupt Climate Change. A report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research, U.S. Geological Survey, Reston VA.