WASHINGTON –– Global average temperatures reached their sixth highest of all-time in 2021, NASA and the National Oceanic and Atmospheric Administration announced on Thursday.
“We’ve reached a point where this global warming data that we’re talking about is no longer an esoteric or academic measure of what’s going on, but it’s been reflected in the weather,” said Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies in New York.
The agencies conducted separate, independent analyses, both finding that last year’s temperatures rose above their baseline averages – NASA by 1.52 degrees Fahrenheit, NOAA by 1.51. The past eight years now rank among the eight hottest on record, according to NOAA and NASA data.
“We expect to see more of these types of extremes in a warming world,” said Russell Vose, chief of climate monitoring at NOAA’s National Centers for Environmental Information, referring to weather events such as an above-average hurricane season in the Atlantic Ocean, intense summer heat waves in the northwestern U.S. and Europe and destructive cyclones Rai and Surigae in Asia.
The U.S. alone had 20 climate disasters that recorded at least $1 billion in damage, according to Vose. Additionally, 680 people lost their lives during climate events – the highest in a decade.
“Some of the events this year were probably not even possible without global warming,” he said.
However, global temperatures fell from 2020 to 2021, which Schmidt said was likely the result of several factors. The year began with a La Niña event which scientists estimate may have cooled the Earth by .06 degrees Fahrenheit during 2021. But La Niña alone didn’t cause the reduced temperatures. Schmidt said unrelated weather events and resumption of aerosol-producing activities following lockdowns in 2020 may also have driven temperatures down.
Among the most affected regions in 2021 was the Arctic Circle, he said. Over the past 30 years, temperatures in the Arctic have increased at over three times the rate of the rest of the world. But these changes aren’t isolated. Schmidt noted that melting glaciers and ice sheets can contribute to rising sea levels and thawing permafrost leads to greater carbon dioxide and methane in the atmosphere.
“What happens in the Arctic doesn’t stay in the Arctic, and the changes there are extremely dramatic,” Schmidt said.
Looking forward, Vose said there is a 99 percent chance that 2022 will rank among the top 10 hottest years and a 50 percent chance it will place in the top five. Increasing amounts of heat-trapping gases like carbon dioxide in the atmosphere will drive this, he added.
Both Schmidt and Vose said it would be difficult to make predictions about what exactly extreme weather events will look like or where they will occur over the next two years. But they agreed that these events are likely to increase in frequency as global temperatures continue to rise.
“We can predict with some confidence that we will see more and more extreme heat waves and intense rainfall and coastal flooding,” Schmidt said. “Exactly where those will happen and what the impacts will be are unclear, but in a statistical sense, I think we can make those predictions.”