Antarctica Is Stealing Australia’s Thunder
Australia's Millennium Drought, which started in the mid-1990s and continued until 2012, was considered to be the worst on record, and resulted in huge losses for farmers and other economies dependent on rain. Many parts of Southern Australia still experience frequent droughts, and researchers from Australian National University have discovered a possible reason why. As increasing carbon dioxide levels in the atmosphere cause stronger winds in the Southern Ocean, rain clouds meant for Australia are being pushed toward Antarctica. This process could also explain why global warming is occurring at a slower pace in the Arctic region.
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"With greenhouse warming, Antarctica is actually stealing more of Australia's rainfall," lead researcher Nerilie Abram, from the university's Research School of Earth Sciences, said in a press release. "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."
These strong winds passing through the Drake Passage - extending from the tip of South America to the Southern Ocean - are warming the climate at an accelerated rate, causing rapid increases in summer ice melt, glacier retreat, and ice shelf collapses in the Antarctic Peninsula. Information on climate change in the Arctic had been fairly inaccessible before this study, with records only dating as far back as the middle of last century. But by analyzing indicators like ice cores, tree rings, and lakes in South America, Abram and her colleagues were able to create a timeline for the westerly winds as far back as 1,000 years.
"The Southern Ocean winds are now stronger than at any other time in the past 1,000 years," Abram said in the release. "The strengthening of these winds has been particularly prominent over the past 70 years, and by combining our observations with climate models, we can clearly link this to rising greenhouse gas levels."
Other researchers involved in the study said that climate change in Antarctica can now be understood to a greater extent. "Strengthening of these westerly winds helps us to explain why large parts of the Antarctic continent are not yet showing evidence of climate warming," Dr. Robert Mulvaney, of the British Antarctic Survey, said in the release.
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