Atmospheric Methane Levels are Increasing, but Why?

methane_eoe_atmosphere

by Emil Morhardt

Methane (CH4) is a much stronger—30 times as strong—greenhouse gas than CO2 in the short term, but has a much shorter atmospheric lifetime, being oxidized to CO2 by another atmospheric chemical entity, the hydroxyl radical (OH-). But either the production of CH4 has been increasing, or that of OH- decreasing, because since 2007 atmospheric levels of CH4 have increased by 3% after years of being flat. Why?

Is it the large amounts of CH4 now known to have been released by fracking? This has seemed a likely candidate, but Paul Voosen (2016) writing about a session in the American Geophysical Union annual meeting in San Francisco in December, indicates that the data are not compelling. Continue reading