2020 was officially one of the warmest years on record, a sign of inevitable global warming, according to a handful of analyzes published worldwide by scientists over the past week.
The heat record comes after a year of climate disasters: historic heat waves, hurricanes and wildfires.
“This is a clear indication that the global signal of climate change by humans is now just as powerful as the force of nature,” Petteri Taalas, secretary general of the World Meteorological Organization, said in a statement.
The analyzes do not agree on whether 2020 was the hottest year ever recorded. A NASA report published on Thursday found that 2020 beat 2016 as the hottest year ever, effectively tying the record. Another analysis, published by the National Oceanic and Atmospheric Administration on Thursday, concluded that 2020 was a short cut for 2016. And last week, the European Union’s Copernicus Climate Change Service determined that 2020 with 2016 would be the hottest year.
The conclusions differ slightly because research groups apply different techniques to compile a worldview of temperatures based on temperature observations of thousands of weather stations.
The 2020 heat record is just the latest in a series of years hit with more heat.
“The past seven years have been the warmest seven years recorded,” said Lesley Ott, a NASA researcher. So, no matter where individual years fall, ‘the consistency that the most recent years are the warmest on record is very, very clear,’ she said.
For all of these analyzes, ‘the difference between 2020 and 2016 is smaller than the uncertainty in the record,’ Zeke Hausfather, a climate scientist at independent research group Berkeley Earth, told BuzzFeed News in an email. “So it’s a tie for the hottest.”
2020 was characterized by heat for most of the year, and was just blunted towards the end by the natural cooling phenomenon, La Niña.
“The extraordinary heat of 2020 is despite a La Niña event, which has a temporary cooling effect,” Taalas said.
Climate change has set other major heat records in 2020.
Siberia experienced a month-long heat wave and the Arctic city of Verkhoyansk recorded the hottest day on June 20, reaching 100 degrees Fahrenheit on June 20.
According to the Copernicus analysis, 2020 was the warmest year in Europe that was 1.6 degrees Celsius above the average temperature, from 1981 to 2010. 2019 held this record previously, where observed temperatures were 0.4 degrees Celsius higher than the same period .
Last year was also the busiest hurricane season in the Atlantic, as well as a historically damaging series of wildfires in the western US. As a result, the US experienced its biggest billion-dollar disaster in 2020. The year also began with some of the worst forest fires in Australia’s history. In addition, carbon dioxide levels continued to rise in the atmosphere, reaching a new maximum of 413 parts per million last May.
Meanwhile, the pandemic caused an economic shock that caused US emissions to fall by an estimated 10.3% in 2020, according to a preliminary analysis by research organization Rhodium Group, which was part of a larger trend of declining emissions worldwide last year. But a short-term reduction in emissions will not be enough to curb the global warming trend – it will require long-term reductions.
“The vast majority of the warming we are seeing is due to the emission of greenhouse gases by humans,” Ott said.