Russian heat wave ‘had both manmade and natural causes’

The heat wave that struck western Russia in summer 2010, causing 55,000 deaths, was caused by a combination of manmade and natural factors. However, the frequency of occurrence of such heat waves has increased by a factor of three over recent decades, new research suggests.

A study, led by Oxford University scientists including Neil Massey of the Smith School of Enterprise and the Environment, reconciles apparently contradictory results from two separate 2011 studies attributing the extreme weather to natural variability and human-induced climate change.

The research is published in the journal Geophysical Research Letters and estimates that the risk of a heat wave of this magnitude has tripled due to the global warming trend since the 1960s, which is mostly attributable to manmade greenhouse gas emissions.

The 2010 Russian heat wave was a devastating extreme weather event, with monthly temperatures more than 5 degrees Celsius above average – daily temperatures peaked at up to 12 degrees above average, reaching over 40 degrees Celsius (104F). These conditions also caused a 25% drop in annual crop production and a total economic loss of more than $15 billion.

 Neil Massey commented:

“These results show that the same weather event can be both ‘mostly natural’ in terms of magnitude and ‘mostly human-induced’ in terms of probability. Thinking in these terms makes it possible to calculate, for instance, how much human-induced climate change cost the Russian economy in the summer of 2010.”

 To view the full press release, click here.