Charts of the Day

Methane (CH₄) is a greenhouse gas which, because of its greater potential to trap heat, worries enviros even more than CO₂. So are methane concentrations rapidly rising (prompting calls for emission reductions and offsets) or substantially stable?

World Climate Report recently answered:

source: The Ups and Downs of Methane

Figure 1. Atmospheric methane concentrations, 1985-2008, with the IPCC methane projections overlaid (adapted from: Dlugokencky et al., [Observational constraints on recent increases in the atmospheric CH₄ burden. Geophysical Research Letters, 36, L18803, doi:10.1029/2009GL039780] 2009)


source: The Ups and Downs of Methane

Figure 2 shows the year-over-year change in the methane concentration of the atmosphere, and indicates not only that the growth rate of methane has been declining, but also that on several occasions during the past decade or so, it has dropped to very near zero (or even below) indicating that no increase in the atmospheric methane concentration (or a even a slight decline) occurred from one year to the next.

BTW, U.S. government data from Alaska is similar.

World Climate Report concludes:

This behavior is quite perplexing. And while we are not sure what processes are behind it, we do know one thing for certain--the slow growth of methane concentrations is an extremely cold bucket of water dumped on the overheated claims that global warming is leading to a thawing of the Arctic permafrost and the release of untold mega-quantities of methane (which, of course, will lead to more warming, more thawing, more methane, etc., and, of course, to runaway catastrophe).

(via Watts Up With That?)