The numbers are in, and scientists can now confirm what month after month of extraordinary heat worldwide began signaling long ago. Last year was Earth’s warmest by far in a century and a half.
Global temperatures started blowing past records midyear and didn’t stop. First, June was the planet’s warmest June on record. Then, July was the warmest July. And so on, all the way through December.
Averaged across last year, temperatures worldwide were 1.48 degrees Celsius, or 2.66 Fahrenheit, higher than they were in the second half of the 19th century, the European Union climate monitor announced on Tuesday. That is warmer by a sizable margin than 2016, the previous hottest year.
To climate scientists, it comes as no surprise that unabated emissions of greenhouse gases caused global warming to reach new highs. What researchers are still trying to understand is whether 2023 foretells many more years in which heat records are not merely broken, but smashed. In other words, they are asking whether the numbers are a sign that the planet’s warming is accelerating.