The climate crisis affects every place on the planet but some are more affected than others. For a long time, Antarctica appeared to be fairly stable in the face of our warming world. Some regions experienced unexpected cooling, which gave us reasons to be optimistic. Unfortunately, recent observations paint a more concerning picture.
The latest research, published in Nature Climate Change, shows that the South Pole has experienced a record warming of 1.8°C (3.3°F) over the last 30 years. That’s three times higher than the expected temperature increase due to anthropogenic global warming. The work highlights a complexity regarding Antarctica’s temperature variations we are yet to fully comprehend.
Data for the study links the increase in temperature around the South Pole to phenomena further north. In 2018, the region was 2.4°C (4.3°F) warmer than the decades 1981-2010. This was due to a strong cyclonic anomaly in the Weddell Sea around Antarctica. This anomaly was caused by high sea-surface temperatures in the western tropical Pacific Ocean, which in turn led warm, moist air to move toward the Antarctic interior, reaching the South Pole.
“This shows how intimately linked the climate of Antarctica is to tropical variability. Our study also shows how atmospheric internal variability can induce extreme regional climate change throughout the Antarctic interior, which has masked any anthropogenic warming signal there during the 21st century,” lead author Dr Kyle Clem from the University of Wellington said in a statement.
“In fact, the South Pole over the past 30 years has warmed more than three times faster than the global average warming, while over the same period the warming on the Antarctic Peninsula and across West Antarctica stopped and even reversed.”
This research really brings home how complex it is to model Antarctica's changing climate. Strong variations in temperature in the region are certainly possible without the effect of human activities, but the comparison to models suggests that there is only a remote possibility that it is unrelated to greenhouse gas emissions.
The team is interested in continuing to study how anomalies in the atmosphere around the southernmost continent affect its ice sheet and its surrounding seas.
“So while our study identified the likely cause of the strong cyclone and its impact on interior Antarctic temperature, what else has this unusual circulation done to the local sea ice and cryosphere, and will it continue in the future?” Clem concluded.