How much of the warming can be attributed to natural and manmade causes remains little understood.
The planet is warming. That we’ve known. It is warming much fastest near the poles. That we’ve also known. Yet just how fast that warming has been still comes as a surprise.
The Arctic has warmed by 0.75 degrees Celsius over the last decade alone, which is a rate much faster than the global average, according to a recent study.
Now comes a new study with some bad news for the southernmost regions. The South Pole, too, is warming much faster than the global average: more than three times faster over the past three decades.
The main authors of the study, a professor of meteorology at the Scalia Laboratory for Atmospheric Analysis in the United States and a climate scientist at Victoria University of Wellington in New Zealand, attributed the rapid pace of warming mainly to natural tropical climate variability intensified by increases in the atmospheric levels of greenhouse gases.
The researchers, who analyzed data collected from weather stations at the South Pole and relied on climate models, found that between 1989 and 2018, this southernmost region of the planet warmed by about 1.8 degrees Celsius at a rate of +0.6 degrees Celsius per decade, which is three times the global average.
“The warming resulted from a strong cyclonic anomaly in the Weddell Sea caused by increasing sea surface temperatures in the western tropical Pacific,” the scientists explain. “This circulation, coupled with a positive polarity of the Southern Annular Mode, advected warm and moist air from the South Atlantic into the Antarctic interior. These results underscore the intimate linkage of interior Antarctic climate to tropical variability.”
During each year much of Antarctica undergoes extreme swings in temperature with marked regional variations. Yet most of West Antarctica and the Antarctic Peninsula has experienced significant warming in recent decades, which has led to the thinning of local ice sheets. The South Pole in the remote interior, too, has warmed significantly since the 1980s, the scientists say.
How much of this warming can be attributed to natural causes and now much of it to manmade ones remains little understood so far. Yet the authors of the study argue that the pronounced warming trends in Antarctica cannot be down simply to natural causes. Rather, our greenhouse gas emissions are likely intensifying these trends.