20 July 2016, Carbon Brief, In the latter half of the 20th century, the tip of the Antarctic Peninsula was among the fastest warming places on Earth. But since the late 1990s, this fast-paced warming has been tempered by extreme natural forces, according to new research. So much so, that some parts have switched to cooling. In many ways, the results are unsurprising. Scientists know that natural variability superimposes temporary ups and downs on top of greenhouse gas-induced warming everywhere on Earth. Prof Robert Mulvaney, part of the team of British Antarctic Survey scientists who carried out the research, tells Carbon Brief: “The results are as we would expect.” The authors of the study, published today in Nature, also stress their findings are restricted to a small part of the Antarctic Peninsula, and do not imply cooling across the ice sheet as a whole. Read More here
Category Archives: Antarctica
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
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