2020 was officially one of the hottest years on record, a sign of undiminished global warming. This emerges from a handful of analyzes published by scientists around the world over the past week.
The heat record comes after a year interrupted by climate disasters: historic heat waves, hurricanes and forest fires.
“This is a clear indication that the global signal of man-made climate change is now as strong as the force of nature,” said Petteri Taalas, general secretary of the World Meteorological Organization, in a statement.
The analyzes do not agree on whether 2020 was the hottest year ever recorded. A NASA report released on Thursday found that 2020 narrowly beat 2016 as the warmest year ever, effectively tying the record. Another analysis released Thursday by the National Oceanic and Atmospheric Administration concluded that 2020 is just behind 2016. Last week, the European Union’s Copernicus Climate Change Service determined that 2020 is the warmest year, making 2016 the warmest year.
The conclusions differ slightly as research groups use different techniques to compose a global temperature picture based on temperature observations from thousands of weather stations.
The heat record for 2020 is only the last in a number of years that have been more heat.
“The past seven years have been the warmest in seven,” said Lesley Ott, a NASA researcher. Regardless of where the years are, “the consistency of the last few years, which are the warmest in history, is very, very clear,” she said.
For all of these analyzes, “the difference between 2020 and 2016 is less than the uncertainty in the record,” Zeke Hausfather, climate researcher at the independent research group Berkeley Earth, told BuzzFeed News via email. “So it’s practically a draw for the warmest.”
The year 2020 was marked by scorching heat for most of the year, which was only dulled towards the end by the natural cooling phenomenon of La Niña.
“The exceptional heat of 2020 is despite a La Niña event that has a temporary cooling effect,” Taalas said.
Climate change has led to further important heat records in 2020.
Siberia experienced a month-long heat wave and the arctic city of Verkhoyansk celebrated its hottest day in existence on June 20, hitting 100 degrees Fahrenheit. “This event would have been virtually impossible without human-made climate change,” concluded a team of scientists.
2020 was the warmest year in Europe and, according to Copernicus’ analysis, was 1.6 degrees Celsius above the average temperature from 1981 to 2010. 2019 had previously held this record, in which the observed temperatures were 0.4 degrees Celsius higher than in same period.
Last year was also the busiest known hurricane season in the Atlantic, as well as a historically damaging series of wildfires in the western United States. The result was that in 2020, the US experienced the largest number of $ 1 billion worth of disasters. The year also began with some of the worst bush fires in Australian history. In addition, carbon dioxide levels in the atmosphere continued to rise, reaching a new maximum of 413 ppm last May.
Meanwhile, the pandemic sparked an economic shock that resulted in an estimated 10.3% decrease in U.S. emissions in 2020, according to a preliminary analysis by research organization Rhodium Group. This was part of a larger trend in global emissions declining over the past year. However, a brief drop in emissions will not be enough to curb the global warming trend – it will require long-term emissions reductions.
“The vast majority of the warming we see is due to human emissions of greenhouse gases,” Ott said.