The World Is Having Its Hottest Year Ever—Again

For the second year in a row, Earth will almost certainly be the hottest it’s ever been. And for the first time, the globe this year reached more than 1.5 degrees Celsius (2.7 degrees Fahrenheit) of warming compared to the pre-industrial average, the European climate agency Copernicus said Thursday.

“It’s this relentless nature of the warming that I think is is worrying,” said Carlo Buontempo, director of Copernicus.

Buontempo said the data...