The release in August of the Intergovernmental Panel on Climate Changes sixth assessment report on climate change and its summary for policymakers, has prompted the media to report that it is code red for the planet. The reaction from many people was one of genuine alarm. But does the report really provide anything new or alarming? Several of the most overstated findings have been presented already in one form or another since the fifth assessment report came out in 2014.
The summary follows the pattern of those in past assessment reports by presenting results meant to get the maximum attention from politicians and the media. One of the first findings in the latest one is that the previous decades mean global temperature was 0.8 1.3 degrees Celsius warmer than the late 19th century temperatures, with a best estimate of 1.07 degrees Celsius. But this result is not newsworthy. Weve heard it many times in relation to the 1.5 degree Celsius so-called target for limiting global warming as given by the IPCC. Almost everyone concedes it is warmer today than it was in the late 19th century, but we still cannot be entirely sure how much warmer. The report presents the finding as likely, with 66 -100 percent confidence if you read the fine print. The lower end of the likely confidence range would not pass peer review.