28 March, Science Daily, Climate change: Greenland melting tied to shrinking Arctic sea ice. Vanishing Arctic sea ice. Dogged weather systems over Greenland. Far-flung surface ice melting on the massive island. These dramatic trends and global sea-level rise are linked, according to a study coauthored by Jennifer Francis, a research professor in Rutgers University’s Department of Marine and Coastal Sciences. During Greenland summers, melting Arctic sea ice favors stronger and more frequent “blocking-high” pressure systems, which spin clockwise, stay largely in place and can block cold, dry Canadian air from reaching the island. The highs tend to enhance the flow of warm, moist air over Greenland, contributing to increased extreme heat events and surface ice melting, according to the study. That, in turn, fuels sea-level rise, said Francis, who called rising seas a “monstrous” issue for coastal communities around the world. The increased melting on the Greenland ice sheet in recent years may also be linked to cooler-than-normal ocean temperatures south of the island, slowing ocean circulation. The study, published online in the Journal of Climate last month, tapped computer models and measurements in the field. “I think this study does a good job of pinning down the fact that the [Arctic sea] ice is disappearing for a whole bunch of reasons — and that is causing the surface of Greenland’s melt area to increase,” Francis said. The Greenland ice sheet holds an enormous volume of frozen water, and the global sea level would rise about 20 to 23 feet if it all melted, the study notes. Surface melting of the ice sheet has increased dramatically since the relative stability and modest snow accumulation in the 1970s, the study also notes. Read More here
Category Archives: The Science
28 March 2016, NASA, 2016 Arctic sea ice wintertime extent hits another record low. Arctic sea ice appears to have reached a record low wintertime maximum extent for the second year in a row, according to scientists at the NASA-supported National Snow and Ice Data Center (NSIDC) and NASA. Every year, the cap of frozen seawater floating on top of the Arctic Ocean and its neighboring seas melts during the spring and summer and grows back in the fall and winter months, reaching its maximum yearly extent between February and April. On March 24, Arctic sea ice extent peaked at 5.607 million square miles (14.52 million square kilometers), a new record low winter maximum extent in the satellite record that started in 1979. It is slightly smaller than the previous record low maximum extent of 5.612 million square miles (14.54 million square kilometers) that occurred last year. The 13 smallest maximum extents on the satellite record have happened in the last 13 years. The new record low follows record high temperatures in December, January and February around the globe and in the Arctic. The atmospheric warmth probably contributed to this lowest maximum extent, with air temperatures up to 10 degrees Fahrenheit above average at the edges of the ice pack where sea ice is thin, said Walt Meier, a sea ice scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Read More here
25 March 2016, Climate News Network, Past emissions cause mounting climate havoc. Despite signs that the world will cut its future fossil fuel use, greenhouse gases already emitted are still driving accelerating climate change.Climate change has reached the point where it may outstrip the quickening efforts to slow it by reducing emissions of carbon dioxide and other greenhouse gases, scientists say. They say humans are now releasing CO2 into the atmosphere 10 times faster than natural processes have ever done in the last 66 million years, before the extinction of the dinosaurs. The disclosure comes in the World Meteorological Organisation’s State of the Climate report, published in the journal Nature Geoscience. The lead author, Professor Richard Zeebe of the University of Hawaii, said: “Our carbon release rate is unprecedented over such a long time period [and] means that we have effectively entered a ‘no-analogue’ state. “The present and future rate of climate change and ocean acidification is too fast for many species to adapt, which is likely to result in widespread future extinctions.” “The window of opportunity for limiting global temperature rise to well below 2°C . . . is narrow and rapidly shrinking. The effects of a warming planet will be felt by all” The UN secretary-general, Ban Ki-moon, said: “Climate change is accelerating at an alarming rate. The window of opportunity for limiting global temperature rise to well below 2°C – the threshold agreed by world governments in Paris in December last year – is narrow and rapidly shrinking. The effects of a warming planet will be felt by all.” The WMO secretary-general, Petteri Taalas, said the present “alarming” rate of climate change as a result of greenhouse gas emissions was “unprecedented in modern records”. “The future is now”, he said. Yet less than a week ago the International Energy Agency announced that global energy-related emissions of carbon dioxide had shown no increase for the second year in a row. The announcement was widely hailed as significant good news, with the IEA’s executive director, Fatih Birol, describing it as “yet another boost to the global fight against climate change”.Read More here
18 March 2016, The Guardian, Welcome to the climate emergency: you’re about 20 years late February 2016 saw global warming records tumble with new data suggesting more Australians think humans are the cause. Everywhere you look right now, the Earth’s climate system seems to be breaking records. To choose the most inappropriate metaphor possible, February 2016 would have been enough to bring a lot of climate watchers out in a cold sweat. Figures from Nasa using thermometers and ocean temperature readings showed February was the hottest month on record, by quite a margin. According to satellite data, the amount of Arctic sea ice also hit an all-time low for this time of year since measurements began in 1979. Scientists also use satellite data to calculate air temperatures. Climate science contrarians and denialists like these readings because they have not shown as much warming as the more reliable readings on the surface. But February also set a new record for global temperatures from satellites. As Joe Romm at Climate Progress noted, “climate science deniers need a new meme”. These heat records have been variously described as “terrifying”, “jawdropping” and “shocking”. One climate scientist in particular, Professor Stefan Rahmstorf, appeared to capture the mood with a quote repeated in stories around the world, including here on the Guardian. “We are in a kind of climate emergency now,” said Rahmstorf, of Germany’s Potsdam Institute for Climate Impact Research. But here’s the rub. Global warming is proceeding pretty much exactly as predicted. Professor Stefan Rahmstorf. To climate scientists like Rahmstorf, the temperature records being broken right now are not a surprise and, at least according to Rahmstorf, they shouldn’t be seen as an entry point to some terrifying new era (at least not as terrifying as things already are). “The media’s view is too short-term,” he told me. “As scientists we want to keep an overview of all the data and the knowledge of how the whole system works.” Read More here