12 October 2017, BBC News, Ozone layer recovery could be delayed by 30 years. Rising global emissions of some chlorine-containing chemicals could slow the progress made in healing the ozone layer.A study found the substances, widely used for paint stripping and in the manufacture of PVC, are increasing much faster than previously thought. Mainly produced in China, these compounds are not currently regulated. Experts say their continued use could set back the closing of the ozone hole by up to 30 years. Scientists reported last year that they had detected the first clear evidence that the thinning of the protective ozone layer was diminishing. The Montreal Protocol, which was signed 30 years ago, was the key to this progress. It has progressively helped governments phase out the chlorofluorocarbons and the hydrochlorofluorocarbons that were causing the problem. However, concern has been growing over the past few years about a number of chemicals, dubbed “very short-lived substances”. Antarctic ozone hole starts to ‘heal’ How Arctic ozone hole was avoided Weather ‘behind ozone hole changes’ Dichloromethane is one of these chemicals, and is used as an industrial solvent and a paint remover. Levels in the atmosphere have increased by 60% over the past decade. Read More here
Tag Archives: Antarctica
12 October 2017, BBC News, Ozone layer recovery could be delayed by 30 years. Rising global emissions of some chlorine-containing chemicals could slow the progress made in healing the ozone layer.A study found the substances, widely used for paint stripping and in the manufacture of PVC, are increasing much faster than previously thought. Mainly produced in China, these compounds are not currently regulated. Experts say their continued use could set back the closing of the ozone hole by up to 30 years. Scientists reported last year that they had detected the first clear evidence that the thinning of the protective ozone layer was diminishing. The Montreal Protocol, which was signed 30 years ago, was the key to this progress. It has progressively helped governments phase out the chlorofluorocarbons and the hydrochlorofluorocarbons that were causing the problem. However, concern has been growing over the past few years about a number of chemicals, dubbed “very short-lived substances”. Antarctic ozone hole starts to ‘heal’ How Arctic ozone hole was avoided Weather ‘behind ozone hole changes’ Dichloromethane is one of these chemicals, and is used as an industrial solvent and a paint remover. Levels in the atmosphere have increased by 60% over the past decade. Read More here
12 July 2017, New York Times, An iceberg the size of Delaware just broke away from Antarctica. A chunk of floating ice that weighs more than a trillion metric tons broke away from the Antarctic Peninsula, producing one of the largest icebergs ever recorded and providing a glimpse of how the Antarctic ice sheet might ultimately start to fall apart. A crack more than 120 miles long had developed over several years in a floating ice shelf called Larsen C, and scientists who have been monitoring it confirmed on Wednesday that the huge iceberg had finally broken free. There is no scientific consensus over whether global warming is to blame. But the landscape of the Antarctic Peninsula has been fundamentally changed, according to Project Midas, a research team from Swansea University and Aberystwyth University in Britain that had been monitoring the rift since 2014. “The remaining shelf will be at its smallest ever known size,” said Adrian Luckman, a lead researcher for Project Midas. “This is a big change. Maps will need to be redrawn.” Read More here
28 May 2017, Climate News Network, Antarctica heights settle polar warming puzzle. Computer simulation shows that Antarctica is warming far slower than the Arctic region because of its much greater height. Scientists believe they have settled one of the great polar puzzles − why Antarctica is warming at a rate so much slower than the Arctic region. And the answer is a simple one: Antarctica is so much higher. To ram the point home, they used a computer simulation to hammer the entire southern continent until it was no more than a metre above sea level. At which point, in their simulation, warming at the South Pole became much more dramatic. The two poles are very different: the Arctic is an ocean almost entirely surrounded by land, while Antarctica is a vast continent entirely surrounded by frozen ocean. Landmass of ice As the north polar ocean ice melts, dark seas begin to absorb more radiation. In the southern hemisphere, the landmass of ice reflects radiation back into space to insulate the continent and keep its temperatures far below freezing. But the new study published in Earth System Dynamics journal shows that what makes the biggest difference is the elevation of the surface. Antarctica is not just an enormous continent: thanks to many millions of years of snowfall at very low temperatures, it is banked high with ancient ice. Its average elevation is 2,500 metres − far higher than the highest peaks in the UK, for example − and its highest mountain, Mount Vinson, reaches 4,892 metres, which is higher than any alpine peak in Europe. Evidence from the distant past and climate models both show that, in a warming world, the poles should warm faster than the rest of the planet. But while the Arctic is warming at twice the rate of the rest of the globe, change in Antarctica has been much more sluggish. Read More here