Climate change made the stifling heat that enveloped parts of Europe last week much more likely and hotter, researchers said Friday.

The heat wave, the second to hit Europe since late June, set temperature records in Paris, as well as in Germany, the Netherlands and other countries. Nuclear reactors in France and Germany were forced to reduce output or shut down because the water used to cool them was too warm.

The hot air, which was trapped over Europe after traveling from northern Africa, lingered for about four days. It has since moved north over Greenland, causing the surface of the island’s vast ice sheet to melt at near-record levels.

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World Weather Attribution, a group that conducts rapid analyses of weather events to see if they are influenced by climate change, said that for France and the Netherlands, the four days of extreme heat last week were a rare event even for a warming world. But it said climate change had made the heat wave at least 10 times more likely. In Germany, the heat wave was at least eight times more likely because of climate change, the group found, and in Britain, where the heat did not linger as long, it was at least two times more likely.