The differences in the rankings were primarily based on how scientists explained the data gaps in the Arctic, which is warming faster than the rest of the world.
“It’s like the movie ‘Groundhog Day.’ Another year, the same story – record global heat, “said Pennsylvania State University climate scientist Michael Mann, who was not part of the measurement teams.
“As we continue to generate carbon pollution, we expect the planet to warm. And that is precisely what we are seeing.”
The scientists said that all you had to do was look outside.
“We saw the heat waves. We saw the fires. We saw the Arctic (melted),” said NASA climate scientist Gavin Schmidt.
“We hope it’s warmer and that’s exactly what happened.”
NOAA said 2020 averaged 58.77 degrees (14.88 degrees Celsius), a few hundredths of a degree less than 2016.
NASA viewed 2020 as warmer than 2016, but so close that they are essentially tied.
The European group Copernicus also called it an essential tie for the hottest year, with 2016 warmer by a negligible fraction.
Japan’s meteorological agency calculated 2020 as warmer than 2016, but a separate calculation by Japanese scientists placed 2020 at a close third to 2016 and 2019.
The World Meteorological Organization, the British weather agency and the Berkeley Earth monitoring team had 2016 ahead.
The first or second classification doesn’t really matter, “but the key to clarify is that the long-term trends in temperature are very clear,” said Schmidt, who heads NASA’s Goddard Institute for Space Studies. that tracks temperatures.
“We are in a position where we are pushing the climate system out of the bounds that it has been in for tens of thousands of years, if not millions of years.”
All monitoring agencies agree that the six warmest years on record have been the six years since 2015.
The 10 warmest have occurred since 2005, and scientists say the warming is driven by burning coal, oil, and natural gas.
The temperatures of the last six or seven years “really point to an acceleration in the rise of global temperatures,” said Russ Vose, chief of the analysis branch of NOAA’s National Centers for Environmental Information.
While temperature increases have clearly accelerated since the 1980s, it is too early to discern a second and more recent acceleration, Schmidt said.
Last year’s exceptional heat “is another stark reminder of the relentless pace of climate change, which is destroying lives and livelihoods across our planet,” United Nations Secretary-General António Guterres said in a statement.
“Making peace with nature is the defining task of the 21st century.”
The United States, which had its fifth warmest year, broke the record for the number of weather disasters that cost at least $ 1 billion with 22 of them in 2020, including hurricanes, wildfires, tornadoes and a Midwest right.
The old record of 16 was set in 2011 and 2017.
This was the sixth consecutive year with 10 or more billion dollar weather disasters, adjusted for inflation.
The Earth has now warmed 1.2 degrees Celsius since pre-industrial times and is adding another 0.2 degrees Celsius per decade.
That means the planet is approaching an international warming threshold set in Paris in 2015, Vose and Schmidt said.
The nations of the world set a goal of preventing at least two degrees Celsius (3.6 degrees Fahrenheit) of warming, with a more stringent secondary goal of limiting warming to 1.5 degrees (2.7 degrees Fahrenheit).
“We can’t avoid 1.5 C above pre-industry right now, it’s too late to turn things around,” University of Oklahoma meteorology professor Jason Furtado, who was not on either team, said in an email. measurement.
“I’m also afraid that the 2C threshold is eluding us as well unless the changes become much more immediate in the United States and other nations.”
The Earth has warmed 0.9 degrees Celsius since 1942, when President-elect Joe Biden was born, and 0.6 degrees Celsius since 1994, when pop star Justin Bieber was born, according to NOAA data.
The main reason agencies have varying numbers is because there are relatively few temperature gauges in the Arctic.
NOAA and the British meteorological agency take a conservative approach in extrapolating the missing data, while NASA estimates that the Arctic is warming much faster than the rest of the world, reaching 38 degrees Celsius in the Russian Arctic last June. said Schmidt of NASA.
The pandemic may have added slightly to last year’s warming, enough to surpass 2020 beyond 2016 in NASA calculations, Schmidt said.
Across the world, people were driving less, and that reduced short-term aerosol pollution, which acts as a cooling agent by reflecting heat.
Schmidt said that fewer cooling aerosols could be responsible for a warming of 05 to .1 degrees Celsius during the year.
NOAA’s Vose and Schmidt expect 2021 to be among the five hottest years, but probably not a record due to natural temporary cooling in parts of the Pacific called La Niña.
Fire, Snow, Heat Waves, and Storms: The Weather Extremes of 2020
NOAA and NASA measurements date back to 1880, while the UK Met Office has readings dating back to 1850.