By Somini Sengupta
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The hottest summers in Europe in the last 500 years have all come in the last 17 years. Several of those heat waves bear the fingerprints of human-caused climate change. In years to come, scientists say, many more are likely to batter what is naturally one of the world’s temperate zones.
“It is quite clear one has to treat it as an emergency,” said Kai Kornhuber, a climate scientist doing postdoctoral research at the Earth Institute at Columbia University.
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Extreme weather events have always happened, and heat waves would occur even without global warming. But a growing field of research called attribution science allows experts to assess how much global warming has stacked the deck in favor of any given weather event. These studies typically use computer models that compare the world as it is now to one in which greenhouse-gas emissions had never occurred.
The 2018 heat wave across Northern Europe, for example, was made five times more likely by climate change, according to an assessment by a group of scientists called World Weather Attribution. The year before, in 2017, a heat wave nicknamed Lucifer, which devastated the Mediterranean, was made at least 10 times more likely by climate change.
For the 2010 heat wave scientists found an 80 percent probability that it would not have happened without climate change. And, in 2003, when temperatures in some parts of France hovered around 37 Celsius for more than a week, a later attribution study found that climate change had doubled the risk.
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