The South Pole has been warming rapidly at more than three times the rate of the global average over the past 30 years, according to a recent study published in Nature Climate Change.
Located in the remote and high-altitude continental interior, the South Pole cooled until the 1980s and has since warmed substantially. These trends are affected by natural and anthropogenic climate changes, but the individual contribution of each factor is not well understood.
According to an international team of climate scientists led by Ohio University professor Ryan Fogt and Ohio alumnus Kyle Clem, this warming period was mainly driven by natural tropical climate variability and was likely intensified by increases in greenhouse gases.
Clem and his team analysed weather station data at the South Pole, as well as climate models to examine the warming in the Antarctic interior. The team found that between 1989 and 2018, the South Pole had warmed by about 1.8 degrees Celsius over the past 30 years at a rate of +0.6 degrees Celsius per decade—three times the global average.
The study also found that the strong warming over the Antarctic interior in the last 30 years was mainly driven by the tropics, especially warm ocean temperatures in the western tropical Pacific Ocean that changed the winds in the South Atlantic near Antarctica and increased the delivery of warm air to the South Pole. The researchers suggest these atmospheric changes along Antarctica's coast are an important mechanism driving climate anomalies in its interior.
The Antarctic climate exhibits some of the largest ranges in temperature during the course of the year, and some of the largest temperature trends on the planet, with strong regional contrasts. Most of West Antarctica and the Antarctic Peninsula experienced warming and ice-sheet thinning during the late 20th century.
Clem and Fogt say that these warming trends were unlikely the result of natural climate change alone, emphasising the effects of added anthropogenic warming that have worked in tandem to make this one of the strongest warming trends worldwide.
Clem, a current postdoctoral research fellow in climate science at Victoria University at Wellington in New Zealand, is the lead author of the study and studied under Fogt for both his bachelor's and master's degrees at Ohio University.
"Working with Ryan, I learned all about Antarctic and Southern Hemisphere climate, specifically how West Antarctica was warming and its ice sheet was thinning and contributing to global sea level rise. I also learned that Antarctica experiences some of the most extreme weather and variability on the planet, and due to its remote location, we actually know very little about the continent, so there are constant surprises and new things to learn about Antarctica every year," said Clem.
