Carbon Dioxide pushing weather around in the southern hemisphere
So why is Antarctica is not warming as much as other continents, and why are there more droughts in southern Australia? According to new Antarctic ice core research published in Nature Climate Change, rising levels of carbon dioxide in the atmosphere are intensifying the Southern Ocean winds, which are known to deliver rain to southern Australia, but instead they are pushing them further south towards Antarctica.
British Antarctic Survey's Dr. Robert Mulvaney, and co-author of the study says: "The strengthening of these westerly winds helps us to explain why large parts of the Antarctic continent are not yet showing evidence of climate warming."
Lead researcher Nerilie Abram, from the Australian National University, said: "With greenhouse warming, Antarctica is actually stealing more of Australia's rainfall. It’s not good news — as greenhouse gases continue to rise we’ll get fewer storms chased up into Australia."
"As the westerly winds are getting tighter they're actually trapping more of the cold air over Antarctica," Abram said. "This is why Antarctica has bucked the trend. Every other continent is warming, and the Arctic is warming fastest of anywhere on earth."
While most of Antarctica is remaining cold, rapid increases in summer ice melt, glacier retreat and ice shelf collapses are being observed along the Antarctic Peninsula, where the stronger winds passing through Drake Passage are making the climate warm exceptionally quickly.
Until this study climate observations of the westerly winds were available only from the middle of the last century.
Dr. Abrams research has chronicled the westerly winds with data from tree rings and lakes in South America and now by analyzing ice cores from Antarctica. Dr. Abram and her colleagues have been able to extend the history of the westerly winds back over the last millennium.
She notes that, "The Southern Ocean winds are now stronger than at any other time in the past 1,000 years."
Read more from the British Antarctic Survey.
Antarctic ice field image via Shutterstock.