Multifold increase in heat extremes by 2040
http://www.pik-potsdam.de/news/press-releases/multifold-increase-in-heat-extremes-by-2040[font face=Serif][font size=5]Multifold increase in heat extremes by 2040[/font]
[font size=4]08/15/2013 - Extremes such as the severe heat wave last year in the US or the one 2010 in Russia are likely to be seen much more often in the near future. A few decades ago, they were practically absent. Today, due to man-made climate change monthly heat extremes in summer are already observed on 5 percent of the land area. This is projected to double by 2020 and quadruple by 2040, according to a study by scientists of the Potsdam Institute for Climate Impact Research (PIK) and the Universidad Complutense de Madrid (UCM). A further increase of heat extremes in the second half of our century could be stopped if global greenhouse-gas emissions would be reduced substantially.[/font]
[font size=3]In many regions, the coldest summer months by the end of the century will be hotter than the hottest experienced today thats what our calculations show for a scenario of unabated climate change, says Dim Coumou of PIK. We would enter a new climatic regime. The scientists focus on heat waves that exceed the usual natural variability of summer month temperatures in a given region by a large margin, namely so called 3-sigma events. These are periods of several weeks that are three standard deviations warmer than the normal local climate often resulting in harvest losses, forest fires, and additional deaths in heat-struck cities.
Information for developing short-term adaptation measures
Such heat extremes might cover 85 percent of the global land area in summer by 2100, if CO[font size="1"]2[/font] continues to be emitted as it is today, the study shows. In addition to this, even hotter extremes that are virtually non-existent today would affect 60 percent of the global land area.
While climate change mitigation could prevent this, the projected increase up to mid-century is expected to happen regardless of the emissions scenario. Therere already so much greenhouse-gases in the atmosphere today that the near-term increase of heat extremes seems to be almost inevitable, Coumou says. This is important information for developing adaptation measures in the affected sectors.
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http://dx.doi.org/10.1088/1748-9326/8/3/034018