The last eight years have been the eight hottest years on record, NASA and the National Oceanic Administration (NOAA) confirmed today. 2021 ranks as the sixth hottest year on record, the agencies said, as global average temperatures trend upward. Rankings aside, there were plenty of red flags throughout 2021 to show us how remarkable the year was for temperature extremes.
“The fact is that we’ve now kind of moved into a new regime ... this is likely the warmest decade in many, many hundreds, maybe 1000s of years,” says Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies. “There’s enough change that it’s having impacts locally.”
In North America, those local impacts included epically bad summer heat, even for typically cool regions. In late June and early July, the Pacific Northwestern US and Western Canada struggled with record-smashing temperatures that buckled roads and melted power cables. In the desert further south, California’s Death Valley reached a blazing 130 degrees Fahrenheit (54.4 degrees Celsius) in July, potentially breaking the world record for the hottest temperature ever recorded on the planet — for the second year in a row.
Across the Atlantic, Europe experienced sweltering heat, too. A reading of 119.8 degrees Fahrenheit (48.8 degrees Celsius) in Sicily might have broken the European record for maximum temperature. (The World Meteorological Organization is still working to vet those records.) All told, July 2021 was the hottest month humans have ever recorded, according to NOAA.
More than a discomfort, the heat took a serious toll on communities. Emergency department visits spiked in the Pacific Northwest as a result of the extreme heat wave, the CDC reported. Further north, an inferno all but wiped out the small town of Lytton, British Columbia soon after it recorded Canada’s highest temperature on record. The event stood out as one of the most shocking of 2021 for Schmidt. “The scale of human tragedy there, you know, even if people don’t die, that’s a community destroyed,” he says.
Heat trapped in the world’s oceans also reached record levels in 2021, according to research published this week. Ocean heatwaves are likely twice as common now as they were in the early 1980s, and they can be devastating for marine life and coastal communities. They kill coral, take a toll on fishing and crabbing industries, and can even make droughts worse onshore.
Temperatures might have been even hotter in 2021, were it not for a La Niña event. La Niña is a recurring climate phenomenon defined by cooler-than-average waters in the eastern equatorial Pacific, which has predictable effects on weather patterns worldwide.
Earlier this week, the European Union’s Copernicus Climate Change Service released its own data on global temperature records, which vary slightly from NASA and NOAA because the agencies use somewhat different methods to make their calculations. Copernicus determined that 2021 was fifth warmest year on record. It also confirmed that the world has warmed by more than a degree Celsius since the preindustrial era, a result of greenhouse gases released by burning fossil fuels. Experts are urging a transition to clean energy because global warming needs to stay well below two degrees Celsius to prevent catastrophic climate change — as this year’s heat extremes illustrate.
“We are unfortunately, reaping what we have sown,” Schmidt says.