For a long time, climatologists thought that, despite the great variability of temperatures on the Antarctic continent, the entire South Pole globally maintained temperatures lower than the rest of the world. However, a recent analysis of 60 years of meteorological measurements has shown that this is not the case. Not only is the South Pole warming, but it is doing it three times faster than the rest of the planet. A rate of warming, according to the researchers, most likely accelerated by greenhouse gases of human origin.
The South Pole has warmed three times faster than the rest of the planet in the past 30 years due to the warmer temperatures of the tropical oceans. The temperature of Antarctica varies considerably by season and region, and for years it was believed that the South Pole had remained cool even as the continent warmed.
A 1.83 ° C increase in just thirty years
Researchers from New Zealand, Britain and the United States analyzed 60 years of weather station data and used computer modelling to show what was causing accelerated warming. They found that warmer ocean temperatures in the western Pacific had, over the decades, lowered atmospheric pressure over the Weddell Sea in the South Atlantic.
In turn, this had increased the flow of hot air directly above the South Pole, warming it by more than 1.83 ° C since 1989. The authors of the research explain that the trend towards natural warming was probably amplified by emissions greenhouse gases of human origin and could mask the warming effect of carbon pollution on the South Pole.
“ As temperatures were known to warm up across West Antarctica and the Antarctic Peninsula during the 20th century, the South Pole was getting colder. It was suspected that this part of Antarctica could be immune/isolated from global warming. We found that this was no longer the case, ”says Kyle Clem, a researcher at Victoria University of Wellington.
Global warming three times faster than the rest of the world
Data has shown that the South Pole is now warming at a rate of about 0.6 ° C per decade, compared to about 0.2 ° C for the rest of the planet. The study authors, published in the journal Nature Climate Change, attribute this change to a phenomenon known as the Inter-Channel Pacific Oscillation (IPO).
The IPO cycle lasts approximately 15 to 30 years and alternates between a positive state – in which the tropical Pacific is warmer and the North Pacific colder than the average – and a negative state, where the temperature anomaly is reversed. The IPO switched to a negative cycle at the beginning of the century, causing greater convection and more extreme pressures at high latitudes, leading to a strong flow of warmer air just above the South Pole.
Clem indicates that the warming level of 1.83 ° C exceeds 99.99% of all warming trends modelled over 30 years. ” While warming was in the natural variability of climate models, it is very likely that human activity has contributed to it .”