Unseasonably warm and even dangerous temperatures this week were up to 30F above average for the time of year

The record-breaking heatwave scorching the US west this week would have been “virtually impossible” if not for the climate crisis, a team of scientists has determined.

Millions of Americans from the Pacific coast to the Rockies baked under unseasonably warm and even dangerous temperatures this week, with temperatures up to 30F (17C) above average for the time of year.

The climate crisis, caused primarily by the burning of fossil fuels, has made this kind of heatwave four times more likely to occur over the last decade, according to a new rapid analysis released Friday.