Global Warming Confirmed With 2˚C Threshold Close At Hand
New studies both confirm global warming and warn there is little time left to keep warming below 2˚C from pre-industrial levels, the target needed to avert dangerous climate change. Berkeley Earth has submitted four papers for peer review that confirm the amount of warming determined by earlier studies. Science Daily reports that previous studies by NOAA, NASA, and the Hadley Center found that the land has warmed by about 1˚C since the mid-1950s, and the Berkeley Earth study finds the same amount of warming. This study differs from previous studies in that it is the first to address the issue of data selection bias by including about five times as many station locations as previous groups.
What’s more, two new papers in Nature Climate Change determine that the 2˚C threshold of averting dangerous climate change may be very close at hand. The first study finds that to have a greater than 66% chance of staying below 2˚C, global emissions must peak before 2020. This means dropping emission levels to about 44 billion tons by 2020, which, according to The Independent, is ambitious considering last year’s emission levels were about 48 billion tons. The second study determines that in higher greenhouse-gas emission scenarios, the 2˚C threshold may be crossed by 2060, but that a lower emissions scenario could delay this by several decades allowing more time for planning. On regional scales, the threshold could be crossed by as early as 2040.