Terrifying assessment of a Himalayan melting

Terrifying assessment of a Himalayan melting

SOURCE: Nepali Times DATE: February 4, 2019 SNIP: While the global media’s attention is on the Greenland ice sheet, the Arctic and eastern Antarctica, a landmark report released this week shows that the Himalaya will face catastrophic meltdown during this century if there is no immediate effort to reduce the world’s carbon emissions. [E]ven in the best-case scenario, the Himalayan mountains will lose more than one-third of their ice by the end of the century. But that would happen only if global average temperatures can be capped at a 1.5oC increase above pre-industrial levels. Most scientists agree that target is unlikely to be met. If current emission trends continue, the world will actually be hotter by between 4.2-6.5oC by 2100 – in which case two-thirds of Himalayan glaciers will be gone. Himalayan peaks are warming between 0.3 to 0.7oC faster than the global average, and the loss of Himalayan ice would have devastating consequences for 1.6 billion people living in the mountains and downstream countries. Climate models show that summer flow in the Indus, Ganges, Brahmaputra and their snow-fed tributaries will actually rise till 2050 as the glaciers melt away, but will start decreasing after that because there will be no more ice...
A landscape unseen in over 40,000 years

A landscape unseen in over 40,000 years

SOURCE: Phys.org DATE: January 25, 2019 SNIP: Glacial retreat in the Canadian Arctic has uncovered landscapes that haven’t been ice-free in more than 40,000 years and the region may be experiencing its warmest century in 115,000 years, new University of Colorado Boulder research finds. The study, published today in the journal Nature Communications, uses radiocarbon dating to determine the ages of plants collected at the edges of 30 ice caps on Baffin Island, west of Greenland. The island has experienced significant summertime warming in recent decades. In August, the researchers collected 48 plant samples from 30 different Baffin ice caps, encompassing a range of elevations and exposures. They also sampled quartz from each site in order to further establish the age and ice cover history of the landscape. Once the samples were processed and radiocarbon dated back in labs at the Institute of Arctic and Alpine Research (INSTAAR) at CU Boulder and the University of California Irvine, the researchers found that these ancient plants at all 30 ice caps have likely been continuously covered by ice for at least the past 40,000...
North American glaciers melting much faster than 10 years ago

North American glaciers melting much faster than 10 years ago

SOURCE: The Guardian DATE: January 19, 2019 SNIP: Glaciers in western North America, excluding Alaska, are melting four times faster than in the previous decade, with changes in the jet stream exacerbating the longer-term effects of climate change, according to a new study. The jet stream – the currents of fast-flowing air in the atmosphere that affect weather – has shifted, causing more snow in the north-western US and less in south-western Canada, according to the study released in Geophysical Research Letters, a publication of the American Geophysical Union. Changes in the northern hemisphere jet stream are increasingly firmly linked to global warming. That warming from humans burning fossil fuels is also expected to continue to melt alpine glaciers, even under scenarios for more moderate greenhouse gas levels. While some of the fourfold increase in the melting rate in western North America is related to manmade climate change, the researchers can’t say with certainty how...
Antarctica losing six times more ice mass annually now than 40 years ago

Antarctica losing six times more ice mass annually now than 40 years ago

SOURCE: Science Daily and PNAS DATE: January 14, 2019 SNIP: Antarctica experienced a sixfold increase in yearly ice mass loss between 1979 and 2017, according to a study published today in Proceedings of the National Academy of Sciences. Glaciologists from the University of California, Irvine, NASA’s Jet Propulsion Laboratory and the Netherlands’ Utrecht University additionally found that the accelerated melting caused global sea levels to rise more than half an inch during that time. “That’s just the tip of the iceberg, so to speak,” said lead author Eric Rignot, Donald Bren Professor and chair of Earth system science at UCI. “As the Antarctic ice sheet continues to melt away, we expect multi-meter sea level rise from Antarctica in the coming centuries.” The team was able to discern that between 1979 and 1990, Antarctica shed an average of 40 gigatons of ice mass annually. (A gigaton is 1 billion tons.) From 2009 to 2017, about 252 gigatons per year were lost. The pace of melting rose dramatically over the four-decade period. From 1979 to 2001, it was an average of 48 gigatons annually per decade. The rate jumped 280 percent to 134 gigatons for 2001 to...
Discovery of recent Antarctic ice sheet collapse raises fears of a new global flood

Discovery of recent Antarctic ice sheet collapse raises fears of a new global flood

SOURCE: Science DATE: December 18, 2018 SNIP: Some 125,000 years ago, during the last brief warm period between ice ages, Earth was awash. Temperatures during this time, called the Eemian, were barely higher than in today’s greenhouse-warmed world. Yet proxy records show sea levels were 6 to 9 meters higher than they are today, drowning huge swaths of what is now dry land. Scientists have now identified the source of all that water: a collapse of the West Antarctic Ice Sheet. Glaciologists worry about the present-day stability of this formidable ice mass. Its base lies below sea level, at risk of being undermined by warming ocean waters, and glaciers fringing it are retreating fast. The discovery, teased out of a sediment core and reported last week at a meeting of the American Geophysical Union in Washington, D.C., validates those concerns, providing evidence that the ice sheet disappeared in the recent geological past under climate conditions similar to today’s. If the finding holds up, the world may need to prepare for sea level to rise farther and faster than expected: Once the ancient ice sheet collapse got going, some records suggest, ocean waters rose as fast as some 2.5 meters per...