The last nine years now rank in the top 10 hottest years since records began and 2021 was the sixth joint hottest year, tying with 2018, according to NASA and the National Oceanic and Atmospheric Administration (NOAA)'s 2021 Annual Global Climate Update.
The detailed report shows the 2021 global land and ocean temperature was 1.04°C (1.87°F) above the pre-industrial average. The goal of the Paris Agreement is to keep the warming below 2°C (3.6°F) although the aspirational goal is actually 1.5°C (2.7°F). Currently, none of the world's largest emitters of greenhouse gases are meeting these requirements.
Earlier this week, the European climate watch counterpart reported 2021 was the fifth hottest on record, highlighting how close this year’s average temperature was to both 2018 and 2015. Different datasets and analyses might have a slightly different ranking, but both analyses agree that the seven hottest years on record all happened in the last seven years.
“The complexity of the various analyses doesn’t matter because the signals are so strong,” Gavin Schmidt, director of GISS, NASA’s leading center for climate modeling and climate change research, said in a statement. “The trends are all the same because the trends are so large.”
The analysis also showed that 2021 was the fourth warmest year for the continental United States since 1895. Several countries have recorded their warmest temperature, a large number was much warmer than average. The report also shows that about 60 percent of the US was in drought or abnormally dry.
In the Northern Hemisphere, the land surface temperature was the third-highest on record after 2020 (warmest) and 2016 (second warmest). It reached 1.09°C (1.96°F) above the 20th-century average. For the Southern Hemisphere surface temperature was the ninth highest on record. Australia tied for hottest day in the Southern Hemisphere on record at 50.5°C (123°F).
In perfect agreement with the European analysis, record temperatures were seen across northern Africa, southern Asia, and southern South America. The analysis also showed that oceans are storing a record-breaking amount of heat, breaking the record set by 2020. This agrees with the analysis published this week showing the world’s ocean heat records have been broken every year for six years straight.
La Niña was also present this year meaning cooler temperatures in the Eastern Pacific. However, 2021 was the 45th consecutive year on record with global temperatures above the 20th-century average.
“Science leaves no room for doubt: Climate change is the existential threat of our time,” said NASA Administrator Bill Nelson. “Eight of the top 10 warmest years on our planet occurred in the last decade, an indisputable fact that underscores the need for bold action to safeguard the future of our country – and all of humanity. NASA’s scientific research about how Earth is changing and getting warmer will guide communities throughout the world, helping humanity confront climate and mitigate its devastating effects.”