Pandemic-related strikes may save the Earth’s atmosphere some greenhouse gas emissions last year, but the world has continued to heat up.
Measurements of water temperature around the world indicate that the total amount of heat stored in the upper oceans in 2020 was higher than any other year recorded in 1955, online researchers report on Jan. 13 in Advances in Atmospheric Sciences. Monitoring ocean temperature is important because warmer water melts more ice on the shores of Greenland and Antarctica, raising sea levels (SN: 30/04/20) and overcoming tropical storms (SN: 11/11 / 20).
The researchers estimated the total heat energy stored in the upper 2,000 meters of Earth's oceans using temperature data from moored sensors, drifting probes called Argo floats, underwater robots, and other instruments (SN: 5/19/10). The team found that the waters of the upper ocean contained 234 sextillion, or 1021, more joules of heat energy in 2020 than the annual average from 1981 to 2010. Thermal energy storage increased by about 20 sextillion joules from 2019, the which suggests that by 2020 the Earth’s oceans have absorbed approximately enough heat to boil 1.3 billion kettles of water.
This analysis may overestimate how much the oceans warmed last year, according to study co-author Kevin Trenberth, a climate scientist at the U.S. National Center for Atmospheric Research and currently based in Auckland, New Zealand. Thus, the researchers also analyzed ocean temperature data using a second more conservative method to estimate annual total ocean heat and found that the jump from 2019 to 2020 could be as low as 1 sextillion of July. There are still 65 million boilers boiling.
The other three warmest years recorded for the world’s oceans were 2017, 2018, and 2019. “What we’re seeing here is a variation on the movie Groundhog Day,” says study co-author Michael Mann, a climate scientist at Penn State . “Groundhog Day has a happy ending. That is not if we do not act now to drastically reduce carbon emissions. "