Monthly temperature extremes have become much more frequent, as measurements from around the world indicate. On average, there are now five times as many record-breaking hot months worldwide than could be expected without long-term global warming, shows a study now published in Climatic Change. In parts of Europe, Africa and southern Asia the number of monthly records has increased even by a factor of ten. 80 percent of observed monthly records would not have occurred without human influence on climate, concludes the authors-team of the Potsdam Institute for Climate Impact Research (PIK) and the Complutense University of Madrid.
"The last decade brought unprecedented heat waves; for instance in the US in 2012, in Russia in 2010, in Australia in 2009, and in Europe in 2003," lead-author Dim Coumou says. "Heat extremes are causing many deaths, major forest fires, and harvest losses – societies and ecosystems are not adapted to ever new record-breaking temperatures." The new study relies on 131 years of monthly temperature data for more than 12.000 grid points around the world, provided by NASA. Comprehensive analysis reveals the increase in records.
The researchers developed a robust statistical model that explains the surge in the number of records to be a consequence of the long-term global warming trend. That surge has been particularly steep over the last 40 years, due to a steep global-warming trend over this period. Superimposed on this long-term rise, the data show the effect of natural variability, with especially high numbers of heat records during years with El Niño events. This natural variability, however, does not explain the overall development of record events, found the researchers.
If global warming continues, the study projects that the number of new monthly records will be 12 times as high in 30 years as it would be without climate change. "Now this doesn't mean there will be 12 times more hot summers in Europe than today – it actually is worse," Coumou points out. For the new records set in the 2040s will not just be hot by today's standards. "To count as new records, they actually have to beat heat records set in the 2020s and 2030s, which will already be hotter than anything we have experienced to date," explains Coumou. "And this is just the global average – in some continental regions, the increase in new records will be even greater."
"Statistics alone cannot tell us what the cause of any single heat wave is, but they show a large and systematic increase in the number of heat records due to global warming," says Stefan Rahmstorf, a co-author of the study and co-chair of PIK's research domain Earth System Analysis. "Today this increase is already so large that by far most monthly heat records are due to climate change. The science is clear that only a small fraction would have occurred naturally."
Coumou, D., Robinson, A., Rahmstorf, S. (2013): Global increase in record-breaking monthly-mean temperatures . Climatic Change(online) [doi:10.1007/s10584-012-0668-1]
Weblink to the article: http://link.springer.com/article/10.1007/s10584-012-0668-1
Potsdam Institute for Climate Impact Research (PIK): http://www.pik-potsdam.de
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Traditional knowledge and scientific study are helping us begin to understand what a changing Arctic means for the marine mammal
But its government has been cutting back on climate-change measures, even arguing for a reduction in renewable-energy targets
"Climate change can no longer be denied," Obama said. "It can't be edited out. It can't be omitted from the conversation. And action can no longer be delayed."
In Michigan's orchard country, extreme heat and cold can mean disaster for fruit growers. Now some are using a new twist on old technology to fool trees when sudden, unexpected weather changes occur.
Scientists develop new technique to probe electric fields inside thunderstorms
Bees have a preference for sugar solutions laced with the pesticides, scientists say, as a separate landmark field trial show neonicotinoids harm bee populationBees may become addicted to nicotine-like pesticides in the same way humans get hooked on cigarettes, according to a new study, which was released as a landmark field trial provided further evidence that such neonicotinoids harm bee populations.
This month, the National Oceanic and Atmospheric Administration is flying an airborne research lab over oil and gas producing states.
An effort is underway to figure out how the BP oil spill harmed the Gulf of Mexico ecosystem. The damage may not be as dire as feared, but researchers say it's too soon to know the long-term impacts.
New threats to Europe’s birds and habitats directives highlight broader tensions – and opportunities – at the interface between conservation science and policy.
Rivers filled with hippo faeces may sound disgusting, but the excrement provides nutrition for fish and aquatic insects