5 July 2016, Washington Post, This new Antarctica study is bad news for climate change doubters. or a number of years now, climate change skeptics have argued that there’s a key part of the Earth’s climate system that upends our expectations about global warming, and that is showing trends that actually cut in the opposite direction. This supposed contrary indicator is the sea ice that rings the Antarctic continent, and that reached a new all-time record extent of 7.78 million square miles in September 2014 (see above). As that record suggests, this vast field of ice has been expanding in recent years, rather than shrinking. That means it’s doing the opposite of what is happening in the Arctic, where sea ice is declining rapidly — and also that it’s doing the opposite of what we might expect in a warming world. [Climate change skeptics may be about to lose one of their favorite arguments] Scientists don’t fully understand why Antarctic sea ice is growing — suggested explanations have posited more glacial melt dumping cold fresh water into the surrounding seas, or the way the Antarctic ozone hole has changed the circulation of winds around the continent. In a new study in Nature Geoscience, though, researchers with the National Center for Atmospheric Research (NCAR) in Boulder, Colo., along with colleagues from the University of Washington in Seattle and Australia, suggest that the phenomenon is simply the result of natural variability of the climate system — driven, in this case, by changes in the tropical Pacific Ocean that reverberate globally. Read more here
Tag Archives: Antarctica
16 June 2016, Climate Inside News, Antarctica’s CO2 Level Tops 400 PPM for First Time in Perhaps 4 Million Years. The concentration of heat-trapping CO2 pollution in the atmosphere has passed the 400 parts per million (ppm) threshold in Antarctica for the first time in at least 800,000 years, and possibly as long as four million years, scientists reported this week. The new measurements, reported by British and U.S. research stations, show that every corner of the planet is being affected by the burning of fossil fuels, according to British Antarctic Survey (BAS) scientists who track environmental changes on the frozen continent. “CO2 is rising faster than it was when we began measurements in the 1980s. We have changed our planet to the very poles,” sad British Antarctic Survey scientist Dr. David Vaughn, who reported on the readings from the Halley VI Research Station. Independently, researchers with the National Oceanic and Atmospheric Administration this week also reported a similar reading from the Amundsen-Scott South Pole Station. Read More here
8 June 2016, Climate News Network, Puzzle of Antarctica’s long-term ice loss. Analysis of satellite data records reveals that the worrying loss of hundreds of square kilometres of ice along West Antarctica’s coastline has been occurring for decades. Parts of Antarctica are not only losing ice to the ocean, they have been doing so for 40 years. Geoscientists from the University of Edinburgh and a US colleague report in Geophysical Research Letters that they looked at satellite imagery of West Antarctica’s coastline along a 2,000 km stretch and found that the region has lost 1,000 square kilometres of ice in four decades. The surprise is not that melting occurs, but that it has been happening for such a long time. Frazer Christie, a PhD student, and partners analysed data from NASA, the US Geological Survey and the European Space Agency to find that ice has been retreating along almost the entire coast of Antarctica’s Bellingshausen Sea since satellite records began. Some of the largest changes – where ice has thinned rapidly and retreated several kilometres since 1975 – matched those places where the ice front is deepest. “We knew that ice had been retreating from this region recently, but now, thanks to a wealth of freely available satellite data, we know this has been occurring pervasively along the coastline for almost half a century,” Christie says. Colder water He and his colleagues blame warmer ocean waters, rather than warmer atmosphere.But, paradoxically, a study from the University of Washington in Seattle, US, reports that the waters lapping the continent are not warming substantially − because of a steady upwelling of much colder water from the depths of the Southern Ocean. Read More here
21 May 2016, Climate News Network, Antarctic glacier melt could raise sea level by 3m. A huge glacier in the frozen wastes of East Antarctica, a region previously thought stable, could melt much faster than expected, scientists say. One of Antarctica’s great glaciers could become unstable if global warming continues at the present pace. As warm seas wash the ice shelf, the land-based mass of ice could begin to retreat, cross a critical threshold in the present century and then withdraw 300 kilometres inland. In the course of doing so it would spill tremendous quantities of water into the oceans: enough to raise global sea levels by 2.9 metres and threaten cities that are home to billions. And here is the bad news: glaciologists have known for decades that West Antarctica’s ice sheets are unstable. But the Totten glacier is part of the East Antarctic Ice Sheet, a mass of ice most researchers had believed to be stable and highly unlikely to lose much of its ice, even in a warming world. Scientists from Australia, New Zealand, the US and Britain report in Nature that they explored the underlying geology of the Totten glacier to build up a picture of its advance and retreat over many millions of years. Greater vulnerability “The evidence coming together is painting a picture of East Antarctica being much more vulnerable to a warming environment than we thought,” said Martin Siegert, co-director of the Grantham Institute at Imperial College London. “This is something we should worry about. “Totten Glacier is losing ice now, and the warm ocean water that is causing this loss has the potential to also push the glacier back to an unstable place.” The identification of a weak spot in the bastion of frozen water that embraces East Antarctica is new. But alarm about the rate of melting and the potential for change across the world’s last largely uninhabited continent is not. In the past few years researchers have pinpointed the insidious effect of warming sea currents, and identified immediate hazards to the glaciers of the fast-warming West Antarctic region. Read More here