Global warming’s influence grows despite the presence of a cooling influence in the tropical Pacific
By Andrew FreedmanDec. 7, 2020 at 7:00 a.m. ESTAdd to list
The planet just had its hottest November on record, and 2020 may end up beating 2016 for the ignominious title of the warmest calendar year.
Scientists have linked most, if not all, of the global warming in recent decades to human emissions of greenhouse gases.
The numbers come from the Copernicus Climate Change Service, a program of the European Commission, which is the first of several temperature tracking agencies to report temperature data for November and the first 11 months of the year.
According to Copernicus scientists, global average temperatures during November were 1.4 degrees (0.77 Celsius) above 1981-2010 levels, beating the previous warmest November by a large margin. Australia had its hottest November, which featured multiple severe heat waves, and persistently above-average temperatures continued in Siberia and the Arctic. Meanwhile, Norway, Sweden and England set national records for their hottest November, Copernicus stated in data released
Cooler-than-average temperatures were seen in parts of Africa, Kazakhstan, Canada, West Antarctica and parts of the tropical Pacific Ocean, where a La Niña event is underway.
The presence of La Niña tends to put a damper on global average surface temperatures, and the fact 2020 is headed toward a record or near-record finish anyway can be viewed as an indication of global warming’s increasingly overt influence. Each La Niña year is turning out warmer than the last, as is each El Niño year, on average.
“Record warm years have usually coincided with a strong El Niño event, as was the case in 2016,” World Meteorological Organization Secretary General Petteri Taalas said in a Dec. 2 statement. “We are now experiencing a La Niña, which has a cooling effect on global temperatures, but has not been sufficient to put a brake on this year’s heat. Despite the current La Niña conditions, this year has already shown near record heat comparable to the previous record of 2016.”
It’s “almost certain” that 2020 will be Europe’s hottest calendar year, Copernicus stated in its report, noting the continent had its hottest fall season by a large margin, beating the previous record-holder of 2006.
Globally, the year to beat to set an annual record is 2016, which got a boost from an unusually strong El Niño, which feature above-average sea surface temperatures in the tropical Pacific Ocean.
Copernicus found that for the year-to-date, 2020 and 2016 are showing nearly the same amount of unusual warmth. Given that November 2020 had a higher temperature anomaly than December 2016 did, Copernicus stated, “it would take a large but not unprecedented fall” in global average temperature departures from average between November and December for 2020 to turn out anything other than “similar to or even marginally warmer than 2016.”
In coming weeks, other temperature tracking agencies, including the National Oceanic and Atmospheric Administration and NASA, will report their monthly and year-to-date rankings. Because of differences in the ways they process temperature information from data-sparse regions, such as the rapidly warming Arctic, among other reasons, agencies may rank 2020 slightly differently even though the temperature readings are similar.