When related climate affects are taken into account, methane's overall climate impact is nearly half that of carbon dioxide. (noaanews.noaa.gov)
One cold (or warm) year or season has little to do with overall climate. (livescience.com)
More than 3 billion years ago, the planet's overall climate began to cool and dry out, but these zones show warming over a shorter period of time. (newscientist.com)