'Mega-heatwaves' more likely
London - "Mega-heat waves" like the one that hit Russia and other parts of eastern Europe in 2010 are up to 10 times more likely to occur over the next 40 years and could have serious consequences, scientists said on Thursday.
In a study published in the journal Science, researchers from Portugal, Switzerland, Germany and Spain said the 2010 heat wave was hotter and more widespread than Europe's 2003 heat wave, but another one like it was unlikely until after 2050.
So-called "mega-heat waves" will probably become five to 10 times more likely over the next 40 years in Europe, they wrote, but "the magnitude of the 2010 event was so extreme that despite this increase, the occurrence... over the same region remains fairly unlikely until the second half of the 21st century."
Last year's heat wave hit Russia particularly hard, leading to average temperatures for Moscow of 7.6°C above normal in July.
The researchers, led by David Barriopedro at the University of Lisbon, cited preliminary estimates that in Russia alone, there were more than 55 000 heat-related deaths, extensive wildfires, an annual crop failure of about 25%, and economic losses of around 1% of gross domestic product.
Finland, Ukraine and Belarus also had extreme high temperatures around the same time.
To put the 2010 heat wave into perspective, Barriopedro's team compared it with other heat waves reaching back to 1871, in terms of length, spatial extent and temperature.
Their analysis found the 2010 heat wave was more severe than the one in 2003, and showed at least two summers in this decade have most likely been the warmest of the last 510 years in Europe.
"Our results reveal that... there is an increasing likelihood of 'mega-heat waves' over highly populated areas of Europe with magnitudes such that they would exceed the exceptional current seasonal maxima of western Europe within the next four decades and of eastern Europe afterward," the researchers concluded.
"Given the disastrous effects of the 2003 and 2010 events, these results venture serious risks of simultaneous adverse impacts over large areas if no adaptive strategies are adopted."