2010 Russia heat wave due to natural variability
The 2010 Russian heat wave that killed thousands and cut into that country's grain harvest was primarily due to natural variability, not human-spurred climate change, U.S. scientists said on Wednesday.
There was plenty of circumstantial evidence pointing to human-caused greenhouse gas emissions and the resulting rise in carbon dioxide in the atmosphere, but close investigation showed this was not a major factor, the scientists said in research published online in Geophysical Research Letters.
"It was an off-the-charts intensity event," Randall Dole of the U.S. National Oceanic and Atmospheric Administration said at a telephone news briefing. "It certainly was the most extreme event we had seen, dating back to at least 1880," when modern weather record-keeping began.
Temperatures soared above 100 degrees F (37.77C) in western Russia from July through mid-August 2010. In Moscow, where long-term daily average temperatures for July range from 65 to 67 degrees F (18.33 - 19.44C), daily average July 2010 temperatures climbed to 87 degrees F (30.55C).
Daily average temperatures include night time.
More severe heat waves, intense droughts and wildfires were among the predictions made for a warming world in the 2007 report by the U.N.'s Intergovernmental Panel on Climate Change. Also, the first six months of 2010 were the hottest, globally, on record.
However, Dole and his co-authors found that the kind of massive heat wave that hung over western Russia from July through mid-August was due mainly to a natural phenomenon called atmospheric blocking.
This occurs when high atmospheric pressure builds up and refuses to budge, forcing any cool air and rains to detour around it, like a traffic island on a busy street.
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