PLEA Network

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