South Pole is warming three times faster than the rest of the globe
While the general picture of global warming shows a regular rise in overall temperatures, some parts of the Earth are heating faster than others, with the Arctic a prime example. Scientists have now uncovered a similar accelerated trend taking place at the opposite end of the globe, with 30 years of weather data revealing the South Pole has warmed at more than three times the global rate since 1989.
The research was carried out by an international team of scientists who examined weather station data, gridded observations and climate models to assess the impact of global warming at the South Pole.
Temperatures can vary greatly over the Antarctic continent. Most of West Antarctica and the Antarctic Peninsula, where sea ice loss has recently begun to greatly accelerate, were known to be experiencing a warming trend since the late 20th century, but the South Pole was thought to be different.
This is because of its location on the remote, high-altitude region known as the Antarctic plateau, one of the coldest places on Earth. While the surrounding areas warmed up throughout the late 20th century, the South Pole actually cooled until the 1980s. But the new study shows that change is in the air.
According to the team’s analysis, the South Pole warmed by a total of 1.8 °C (3.24 °F) between 1989 and 2018, and has begun to accelerate since the start of the 2000s. For comparison, the combined land and ocean temperatures across the planet have increased at an average rate of 0.18 °C (0.32 °F) per decade since 1981, according to the National Oceanic and Atmospheric Administration.
The researchers say this is the result of number of elements, though the exact contribution of each is difficult to determine. One factor in this trend, however, is warmer ocean temperatures in the tropical Pacific Ocean, which has lowered atmospheric pressure over parts of the Atlantic and in turn driven warmer air onto the plateau where the South Pole is situated.
The team found that several of the South Pole’s warmest years correlated with unusually warm temperatures in the tropics, and nearly 20 percent of the temperature variations at the South Pole across the period studied could be linked to ocean temperatures in that region.
To understand the role that greenhouse gases and anthropogenic climate change has played in this trend, the team analyzed more than 200 climate model simulations. These factored in the concentrations of greenhouse gases over the 30-year period, and allowed the team to compare the rate of warming to all possible warming trends that would have occurred naturally without human activity.
The researchers say the actual observed warming exceeds 99.9 percent of all possible scenarios free of human influence, so while it is possible it could have occurred naturally, it is “extremely unlikely.” They conclude that increasing greenhouse gas levels have worked in tandem with tropical variability to generate one of the “strongest warming trends on the planet," even greater than that observed in the Arctic, which is warming at almost twice the rate of the rest of the planet.
The research was published in the journal Nature Climate Change.