South Pole warming three times faster than global average due to atmospheric pressure, rise in greenhouse gases
The analysis of weather station data shows it has warmed by 1.8℃ between 1989 and 2018, changing more rapidly since the start of the 2000s
At the South Pole, which lies within the coldest region on Earth -- the Antarctic plateau where average temperatures range from -60℃ during winter to -20℃ during summer -- warming has been increasing rapidly. The South Pole has been one of the fastest-changing places on Earth over the past 30 years, warming more than three times more quickly than the rest of the world, researchers now warn. The study, published in Nature Climate Change, throws new light on the most remote region on Earth and shows how global warming is making its way to these places. The rising temperature could have implications for the melting of Antarctic ice sheets, sea-level rise as well as marine life in the region.
“Climate scientists long thought Antarctica’s interior may not be very sensitive to warming, but our research shows a dramatic change. These warming trends are unlikely the result of natural climate variability alone. The effects of human-made climate change appear to have worked in tandem with the significant influence natural variability in the tropics has on Antarctica’s climate. Together they make the South Pole warming one of the strongest warming trends on Earth,” writes the lead author of the study Kyle R Clem, research fellow in climate science at the Victoria University of Wellington, New Zealand.
The research team from New Zealand, the US, and the UK analyzed 60 years of weather station data and used computer modeling to show what was causing accelerated warming. They looked at changes to air temperatures from data at the Amundsen-Scott South Pole Station, a US research base at the South Pole. It is the world’s most southerly point that has been maintaining temperature records since 1957. The analysis of weather station data shows that the South Pole has warmed by 1.8℃ between 1989 and 2018, changing more rapidly since the start of the 2000s. This warming happened at a rate of +0.61°C per decade -- over three times the global average. Over the same period, the warming in West Antarctica suddenly stopped and the Antarctic Peninsula began cooling.
The scientists explain that one of the dominant reasons for the South Pole warming was stronger low-pressure systems and stormier weather east of the Antarctic Peninsula in the Weddell Sea. With clockwise flow around the low-pressure systems, this has been transporting warm, moist air onto the Antarctic plateau. “Our study also shows the ocean in the western tropical Pacific started warming rapidly at the same time as the South Pole. We found nearly 20% of the year-to-year temperature variations at the South Pole were linked to ocean temperatures in the tropical Pacific, and several of the warmest years at the South Pole in the past two decades happened when the western tropical Pacific ocean was also unusually warm,” says Clem.
To understand whether warming was driven by human activity, the researchers used models that simulate the climate of the Earth with greenhouse gas concentrations. The team examined over 200 climate model simulations with observed greenhouse gas concentrations over the period between 1989 and 2018. They found that recent increases in greenhouse gases have possibly contributed around 1℃ of the total 1.8℃ of warming at the South Pole. The scientists also investigated temperature rise under a scenario minus human-induced greenhouse gas emissions. “We also used the models to compare the recent warming rate to all possible 30-year South Pole temperature trends that would occur naturally without human influence. The observed warming exceeds 99.9% of all possible trends without human influence -- and this means the recent warming is extremely unlikely under natural conditions, albeit not impossible. It appears the effects from tropical variability have worked together with increasing greenhouse gases,” says the research team.