Last month was the hottest November in history, European researchers said Monday as the relentlessly warming climate proved too much for even the possible effects of cooler ocean temperatures in the tropical Pacific.
Scientists from the Copernicus Climate Change Service said global temperatures in November were 0.1 degrees Celsius (about 0.2 degrees Fahrenheit) above previous record-holders in 2016 and 2019. November 2020 was 0.8 degrees Celsius (or 1.5 degrees Fahrenheit) higher than the 1981-2010 average.
Warm conditions continued to prevail over large parts of the planet, with temperatures in northern Europe and Siberia as well as in the Arctic Ocean being above average. Much of the United States was also warmer than average.
The Copernicus service said temperatures so far this year have been at 2016 levels, the hottest year in existence. Subject to a significant drop in global temperatures in December, 2020 is likely to remain linked to 2016, or even to be marginally the warmest in history, the service said.
“These records are consistent with the long-term warming trend of the global climate,” the service’s director Carlo Buontempo said in a statement. “All policy makers who prioritize mitigating climate risks should view these records as alarm bells.”
In September, the world entered La Niña, a phase of the climate pattern that also brings El Niño and affects weather around the world. La Niña is characterized by cooler sea surface temperatures in the eastern and central tropical Pacific. Last month, scientists with the National Oceanic and Atmospheric Administration said La Niña had intensified, meaning surface temperatures continued to drop.
While La Niña can bring warmer conditions to certain regions – especially the southern US – it is generally cooler overall. When the organization’s general secretary, Petteri Taalas, published a climate report from the World Meteorological Organization last week, which stated, among other things, that 2020 will be one of the three warmest years of all time, he said that La Niña’s cooling effect “is not enough to curb this year’s heat. “
Marybeth Arcodia, a graduate student studying climate dynamics at the University of Miami, said there are other elements that affect climate, including natural vibrations of wind, precipitation, barometric pressure, and sea temperatures over various time scales. “There are just so many different climatic factors that could mask the signal from La Niña,” Ms Arcodia said.
The biggest element, however, is man-made climate change.
“It should be noted that the global average temperature is rising at an unprecedented rate due to human influences,” she said. “That’s the main factor here.”
“We’ll see these record-breaking temperatures even when we have climates like La Niña that could bring cooler temperatures.”
The Copernicus Service scientists said the warm conditions in the Arctic last month slowed the freezing of ice in the Arctic Ocean. The extent of sea ice cover was the second lowest in November since satellite observation of the region began in 1979. A slower freeze could result in thinner ice and thus melt more in late spring and summer.
The Arctic was extraordinarily warm for most of the year, part of a long-term trend where the region is warming significantly faster than other regions of the world. The warmth contributed to widespread forest fires in Siberia in the summer and resulted in the second lowest minimum sea ice extent in September, the end of the summer melting season.
The Copernicus Climate Change Service is part of the European Center for Medium-Range Weather Forecasts, which is supported by the European Union. In the United States, NOAA also reports monthly and yearly temperature data, usually later than the European agency. Although the analysis techniques differ, the results are often very similar.