Abstract

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 less... Show moreMethane (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. Show less