Warming Arctic may be responsible for world’s extreme weather

Melting of Arctic is triggering changes in global wind patterns and causing more frequent heatwaves and downpours in northern hemisphere, says research

By Rajit Sengupta
Last Updated: Saturday 04 July 2015


Scientists have blamed the rapid rise in Arctic temperatures over the past two decades for the increase in weather extremes in the northern hemisphere. From heatwaves in the US to flooding in Europe, the number of extreme weather events has almost doubled since 2000. Also, over the past two decades, the Arctic has been growing warmer twice as fast as the rest of the world, which, a new research says, could have triggered changes to global wind patterns. This has brought extreme weather to lower latitudes, the researchers from the Potsdam Institute for Climate Impact Research in Germany say.

The researchers believe that the loss of sea ice in the Arctic may be resulting in the appearance of wide north-south swings in the high-altitude winds flowing globally west to east around the polar region. When the high-altitude winds swing north it brings warm air from the tropics over Europe, Russia or North America, and when it swings south it brings in frigid air from the Arctic, leading to weather extremes in northern hemisphere. 

“The large number of recent high-impact extreme weather events has struck and puzzled us. Of course we are warming out atmosphere by emitting CO2 from fossil fuels, but the increase in devastating heat waves in regions like Europe or the US seems disproportionate,” said Dim Coumou of the Potsdam institute, the lead author of the study.

“Evidence for actual changes in planetary wave activity was so far not clear. But by knowing what patterns to look for, we have now found strong evidence for an increase in these resonance events,” says Stefan Rahmstorf, a climate researcher at the Potsdam institute. “There is a subtle resonance mechanism that traps waves in the mid latitudes and amplifies them strongly,” said Dr Rahmstorf, one of the co-authors of the study, published in the journal Proceedings of the National Academy of Sciences.


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