Scientists set off on a voyage to Antarctica today to see if the icesheets at the edge of the vast continent are melting faster and whether the Southern Ocean is soaking up less climate-warming carbon dioxide.
The Southern Ocean absorbs a large amount of the CO2 emitted by industry, power stations and transport, acting as a brake on climate change. "Some recent results suggest the Southern Ocean is becoming less effective at absorbing CO2 than it used to be," said Steve Rintoul of Australia's government-backed research arm the CSIRO. "If it were to become less effective in absorbing it, that would tend to accelerate the rate of climate change," he said. "Our measurements of how much carbon dioxide is accumulating in the ocean will provide a critical test of this hypothesis." Mr Rintoul is leading an international team of researchers aboard the Aurora Australis that left the southern Australian city Hobart, in Tasmania, today. The scientists from Australia, Britain, France and the United States, will spend nearly a month taking measurements of the Southern Ocean between Antarctica and Hobart to see how the ocean is changing and what those changes might mean for the world's climate. The Southern Ocean is also a key part of the global system of ocean currents that shift heat around the planet, a key driver of the world's weather. Past voyages led by Rintoul have detected changes in the ocean that could mean ice is melting faster in Antarctica. The latest voyages aims to test that theory and the scientists will take a variety of measurements, including salinity, temperature and ocean chemistry, such as carbon dioxide and CFC concentrations.