Preliminary IPCC report predicts increased weather extremes

There is at least a 2-in-3 probability that climate extremes have already worsened because of human-caused releases of heat-trapping gases like carbon dioxide, and some types of extreme weather events will increase in the coming decades as huge cost, says a preliminary draft of an international climate report leaked to the Associated Press (AP) this week. The Nobel Prize-winning United Nations Intergovernmental Panel on Climate Change (IPCC) issues reports on the state of the scientific knowledge of climate change every six years, with the next full report due out in 2013. However, the IPCC is working on a special report detailing the evidence that extreme weather events may be increasing due to climate change, and how we might best prepare for the coming increase in these costly and dangerous events. The IPCC Special Report on Managing the Risks of Extreme Events and Disasters (SREX) is due to be released later this month, after a meeting in Uganda, where diplomats will recommend changes to the preliminary document leaked to AP. The IPCC requires that all countries agree unanimously on the content of the official reports, so the language of the leaked report may undergo considerable change. In the AP article, University of Victoria climate scientist Andrew Weaver, who was not among the authors, is quoted as saying that the report was written to be “so bland” that it may not matter to world leaders. With the diplomats free to make changes to the report, I think it is likely that the already bland SREX report will be further watered down. Despite all the objections one hears about the extreme and dire predictions of the IPCC, the science in these reports is actually very conservative and watered down, due to the requirement that the language must be approved by every country (including oil producing nations such as Saudi Arabia.) So, it should grab our attention that the preliminary draft of the SREX report predicts that some regions of the world might suffer extremes so severe as to leave them "increasingly marginal places to live", heat waves could peak at 5°F hotter by 2050 and 9°F hotter by 2100, and intense single-day rainstorms that happen only once every twenty years now will happen up to once every five years by 2100. I'll have more on the SREX report after its official release.

Jeff Masters