The pattern is likely to revert to drier summers and may do so suddenly, according to Professor Rowan Sutton, at the University of Reading, who led the work. "I can't guarantee it but it is likely," he said. "However we are not sure of the timing, which is what every one wants to know – but we are working on this now." Sutton added that when the switch occurs, it could happen as rapidly as over two to three years.
The summer of 2012 was the wettest in a century and follows a series of above average years for summer rainfall. Sutton's team, who published their study in Nature Geoscience, examined over a century of data and found that the temperature of the North Atlantic remains above or below the long term average for decades at a time. The periods of warmer temperature, the latest of which started in the late 1990s, were found to correlate with wet summers in Northern Europe and hotter, drier summers in the Mediterranean. The team used existing detailed climate simulations to demonstrate a causal link between the warmer oceans and the change in the weather.
Sutton said these shifts have been occurring for many hundreds of years, but that global warming was also having an impact. "It is not now purely natural or purely a manifestation of human-induced climate change," he said. "There is lot of evidence to show that climate change is changing the timing and amplitude of the temperature changes." For example, he said, the cooler period from the 1960s to the 1980s occurred when soot and other pollution from dirty power stations cooled the planet....
A rain in 2008, ruining a silage crop in Devon, shot by paul dickson, Wikimedia Commons via Geograph UK, under the Creative Commons Attribution-Share Alike 2.0 Generic license
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