Last year was one of the the warmest on record, according to data released Thursday by two U.S. government agencies, and was marked by numerous instances of severe weather around the globe, many of which are exacerbated by global warming.
The Earth’s average global surface temperature was 0.86 degrees Celsius above the 20th century average in 2022, according to the National Oceanic and Atmospheric Administration (NOAA) and the National Aeronautics and Space Administration (NASA). This made it the sixth-warmest year on record by NOAA’s reckoning, and the fifth-warmest by NASA’s. (The discrepancy between the two is the result of a measurement difference of a tiny fraction of a degree.)
The high temperatures in 2022 were particularly remarkable because of the presence of a major weather phenomenon over the Pacific Ocean called La Niña, which drove global temperatures down by approximately 0.06 degrees, Gavin A. Schmidt, chief of NASA’s Goddard Institute for Space Studies, said in a conference call with journalists.
Russell Vose, chief of the analysis and synthesis branch at NOAA’s National Centers for Environmental Information, said the individual rankings of specific years are less important than the overall trend of a warming planet. Each of the past eight years has been among the eight hottest years on record.
“It’s clear that each of the past four decades has been warmer than the decade that preceded it,” said Vose. “There's really been a steady rise in temperature since at least the 1960s.”
He added, “It's certainly warmer now than at any time in at least the past 2,000 years, and probably much longer.”
Regional differences
Differences in global surface temperature were not evenly distributed, with some regions experiencing much higher-than-average temperatures, while others had lower temperatures. While Central Europe experienced significantly higher temperatures than normal, for example, the temperatures of the U.S. Midwest were lower than average. The Northern Hemisphere, for example, was 1.1 degrees Celsius above average last year, while the Southern Hemisphere was up only 0.61 degrees.
Asia experienced its second-hottest year on record, as did Europe. In Africa, though, 2022 was only the tenth-hottest year on record. It was the 12th-hottest year recorded in South America, the 15th-hottest in North America and in the top 20 for Oceania.
Much of the increased heat was focused on the polar regions, which led to significant loss of sea ice. In 2022, average sea ice cover in the Antarctic was near record lows, at 10.5 square kilometers. In the Arctic, sea ice covered 10.6 square kilometers, the 11th-lowest total on record.
In addition, average ocean surface temperatures, which are measured up to a depth of 2,000 meters, were the highest on record. The four highest average global ocean temperatures ever recorded have all occurred in the four years since 2019.
Major weather events
Last year also saw a large number of extreme weather events, including crippling droughts in the western U.S., East Africa and much of Europe, while Pakistan, China and Australia all battled devastating floods.
While major storm systems were not more common than average in 2022, North America suffered a series of extremely damaging hurricanes, while East Asia was battered by several destructive typhoons.
The scientists presenting the NOAA/NASA data declined to blame severe weather events specifically on climate change, but they noted that warmer temperatures create conditions that allow storms to become more damaging than they might otherwise be.
‘Flirting’ with 1.5 degrees Celsius
Countries around the world have reached a number of agreements meant to try to keep average global temperature increases limited to 1.5 degrees Celsius above pre-industrial levels (a different, lower baseline than the 20th century average cited above).
Vose said the Earth is already “flirting” with a 1.5-degree increase now, adding that it would not be surprising for a single year in the 2020s to top that number. That would not be the same as reaching a multiyear average increase of 1.5 degrees, though.
Schmidt said the Earth’s average temperature currently stands at between 1.1 and 1.2 degrees above the preindustrial average, and is climbing.
He said the current rate of warming is just over 0.2 degrees Celsius per decade. If that rate remains unchanged, within 20 years, the global average will hit 1.5 degrees.
However, he added, continued increases are not inevitable.
“Future warming is a function of future emissions of carbon dioxide. So, we as a society, collectively, we still have agency,” Schmidt said. “So, what we are going to do in the future is going to determine what happens in the future. And so, if we continue to emit at the rate that we are emitting right now, then we are going to continue to warm, and we would be pretty much rushing past 1.5. If we collectively reduce emissions quite quickly, then we can avoid the higher temperatures.”
Climate activists frustrated
Climate activists saw Thursday’s report as further confirmation of the dire effects of global warming and the insufficiency of past efforts to slow it.
“It's a lot of what we already know — just more confirmation,” said Cherelle Blazer, senior director of the International Climate and Policy Campaign at the Sierra Club. “We're already at 1.1 degrees warming. All the world's scientists say that we need to stick to 1.5 in order to not see the worst of the climate catastrophe happen. And no one seems to be willing to do what's necessary to achieve that. I find it very disheartening.”
Blazer said she hopes the NOAA/NASA report will spur the new Congress into action, particularly in efforts to fully implement the many carbon-reduction efforts included in the recently passed Inflation Reduction Act, to finance the Green Climate Fund, and to take steps to compensate low-income countries for the disproportionate damage they face from global warming.
“I'm hoping that the Biden administration, our new Senate and our new House — our newly elected officials — are ready to roll up their sleeves and stop playing around with people's lives,” she said.
