Pandemic-related shutdowns could have spared Earth’s ambiance some greenhouse fuel emissions final 12 months, however the world continued to heat.
Water temperature measurements from across the globe point out that the full quantity of warmth saved within the higher oceans in 2020 was higher than any other year on record dating back to 1955, researchers report on-line January 13 in Advances in Atmospheric Sciences. Monitoring ocean temperature is essential as a result of hotter water melts more ice off the edges of Greenland and Antarctica, which raises sea ranges (SN: 4/30/20) and supercharges tropical storms (SN: 11/11/20).
Researchers estimated the full warmth vitality saved within the higher 2,000 meters of Earth’s oceans utilizing temperature knowledge from moored sensors, drifting probes called Argo floats, underwater robots and different devices (SN: 5/19/10). The workforce discovered that higher ocean waters contained 234 sextillion, or 1021, joules extra warmth vitality in 2020 than the annual common from 1981 to 2010. Warmth vitality storage was up about 20 sextillion joules from 2019 — suggesting that in 2020, Earth’s oceans absorbed about sufficient warmth to boil 1.3 billion kettles of water.
This evaluation could overestimate how a lot the oceans warmed final 12 months, says examine coauthor Kevin Trenberth, a local weather scientist with the U.S. Nationwide Middle for Atmospheric Analysis who’s at present based mostly in Auckland, New Zealand. So the researchers additionally crunched ocean temperature knowledge utilizing a second, extra conservative technique for estimating complete annual ocean warmth and located that the bounce from 2019 to 2020 may very well be as little as 1 sextillion joules. That’s nonetheless 65 million kettles delivered to boil.
The three different warmest years on file for the world’s oceans had been 2017, 2018 and 2019. “What we’re seeing here’s a variant on the film Groundhog Day,” says examine coauthor Michael Mann, a local weather scientist at Penn State. “Groundhog Day has a contented ending. This gained’t if we don’t act now to dramatically scale back carbon emissions.”