The World Just Experienced the Four Hottest Years on Record

2018 was hotter than any year in the 19th century. It was hotter than any year in the 20th century. It was hotter than any year in the first decade of this century. In fact, with only three exceptions, it was the hottest year on Earth since 1850.

Those three exceptions: 2018 was slightly cooler than 2015, 2016, and 2017. The past four years, in other words, have been the four hottest years ever reliably measured.

That’s according to Berkeley Earth, a nonprofit research group that published its annual temperature analysis on Thursday. The new finding “remains consistent with a long-term trend toward global warming,” the report says.

Berkeley Earth is a respected scientific organization, but it’s unusual that this news should come from it alone. Normally, Americans hear about these milestones from their own government. NASA and the National Oceanic and Atmospheric Administration were both due to publish their version of this analysis last week, on January 17. The United Kingdom’s Met Office and Berkeley Earth also planned to release their own findings that day.

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But the report contains plenty of records worth noting in their own right. 2018 was the hottest year ever recorded in Antarctica, a finding with worrisome implications for sea-level rise. Twenty-nine countries—including France, Germany, Italy, Greece, and the United Arab Emirates, where temperatures hit 123 degrees Fahrenheit in June—experienced their warmest year ever last year, too.

The report also underscores that climate change has already begun—and that we are running out of time to keep it under control. It finds that Earth was about 1.16 degrees Celsius warmer in 2018 than it was during the late-19th century. Last year, the Intergovernmental Panel on Climate Change (IPCC) warned that if global warming exceeds 1.5 degrees Celsius—just 0.4 degrees Celsius above where we are now—then widespread environmental upheaval could result.