2020 just shy of Earth’s hottest year
The year is part of trend alarming climate experts
Global warming didn’t take the year off in 2020: The planet was near record-hot again last year, climate groups announced Thursday.
While NASA said 2020 essentially tied with 2016 as the Earth’s warmest year on record, other groups, such as the National Oceanic and Atmospheric Administration, said it was the secondwarmest year.
“Whether one year is a record or not is not really that important – the important things are long-term trends,” said NASA climate scientist Gavin Schmidt. “The last seven years have been the warmest seven years on record, typifying the ongoing and dramatic warming trend.”
Also, according to NOAA, 2020 was the 44th consecutive year (since 1977) with global temperatures above the 20th-century average.
NOAA and NASA measurements go back to 1880.
“With these trends, and as the human impact on the climate increases, we have to expect that records will continue to be broken,” said Schmidt, director of NASA’s Goddard Institute for Space Studies.
The burning of fossil fuels such as oil, natural gas and coal releases greenhouse gases such as carbon dioxide and methane into the Earth’s atmosphere, causing the globe to warm to levels that cannot be explained by natural causes.
“We’re in a position where we’re
pushing the climate system out of the bounds that it’s been in for tens of thousands of years, if not millions of years,” Schmidt said.
Overall, Earth’s average temperature has risen more than 2 degrees since the 1880s, NASA said.
And although carbon emissions were down in 2020 amid the global COVID-19 pandemic, they continue to accumulate in the atmosphere.
The amount of warming the world experiences is based on total emissions since pre-industrial times, rather than emissions in 2020, according to Zeke Hausfather, a climate scientist and director of climate and energy at the Breakthrough Institute in California.
In fact, surprisingly, the pandemic may have added ever so slightly to last
year’s warming, because people were driving less.
That reduced the short-term aerosol pollution that acts as a cooling agent by reflecting heat.
“What matters for the climate is not the leaderboard of individual years,” Hausfather tweeted Thursday. “Rather, it is the long-term upward trend in global temperatures driven by human emissions of greenhouse gases. Until the world reduces emissions down to netzero, the planet will continue to warm.”
The previous record warm year, 2016, received a significant boost from a strong El Niño. The lack of a similar assist from El Niño this year is evidence that the background climate continues to warm because of greenhouse gases, Schmidt said. La Niña, a natural cooling of Pacific Ocean water that was present toward the end of 2020, tends to lower the global temperature, while El Niño does the opposite.
“It is rather remarkable that a La Niña year could match the warmth of one of the strongest El Niños on record just a few years ago – illustrating the powerful impact that human greenhouse gas emissions are having on global temperatures,” Hausfather wrote on the Carbon Brief website.
Last year’s exceptional heat “is yet another stark reminder of the relentless pace of climate change, which is destroying lives and livelihoods across our planet,” U.N. Secretary-General António Guterres said in a statement.
World Meteorological Organization Secretary-General Petteri Taalas, in a statement in December, said that “2020 has, unfortunately, been yet another extraordinary year for our climate. We saw new extreme temperatures on land, sea and especially in the Arctic.”
“Wildfires consumed vast areas in Australia, Siberia, the U.S. West Coast and South America, sending plumes of smoke circumnavigating the globe,” he said. “We saw a record number of hurricanes in the Atlantic, including unprecedented back-to-back Category 4 hurricanes in Central America in November. Flooding in parts of Africa and Southeast Asia led to massive population displacement and undermined food security for millions.”
In the U.S., the record for the number of weather disasters that cost at least $1 billion was smashed. There were 22 such disasters in 2020, including hurricanes, wildfires, tornadoes and a Midwest derecho.