Decline in krill threatens Antarctic wildlife, from whales to penguins

Decline in krill threatens Antarctic wildlife, from whales to penguins

SOURCE: The Guardian DATE: February 14, 2018 SNIP: The Antarctic, one of the world’s last great wildernesses and home to animals such as whales, penguins and leopard seals, is being threatened by the plight of an animal just a few centimetres long, according to scientists. Researchers and environmental campaigners warn that a combination of climate change and industrial-scale fishing is threatening the krill population in Antarctic waters, with a potentially disastrous impact on larger predators. The report, published in the journal Plos One, warned that climate change could reduce krill size by up to 40% in some areas of Antarctica’s Scotia Sea causing a drastic reduction in predator numbers. Researchers also said that current permitted rates of krill fishing “increased the risk for depletion of some predator populations” although it had “less impact than ocean warming”. Krill populations have declined by 80% since the 1970s. Global warming has been blamed for part of that decrease because the ice that is home to the algae and plankton they feed on is retreating. Campaigners say recent developments in fishing technology are exacerbating the problem, allowing ‘suction’ harvesting by large trawlers which are now able to gather up vast quantities of krill. Krill are a key part of the delicate Antarctic food chain. They feed on marine algae and are a key source of food for whales, penguins and seals. They are also important in removing the greenhouse gas carbon dioxide from the atmosphere by eating carbon-rich food near the surface and excreting it when they sink to lower, colder...
Sea ice tracking low in both hemispheres

Sea ice tracking low in both hemispheres

SOURCE: National Snow and Ice Data Center (NSIDC) DATE: February 6, 2018 SNIP: January of 2018 began and ended with satellite-era record lows in Arctic sea ice extent, resulting in a new record low for the month. Combined with low ice extent in the Antarctic, global sea ice extent is also at a record low. The linear rate of decline for January is 47,700 square kilometers (18,400 square miles) per year, or 3.3 percent per...
Earth’s Ice Is Melting Much Faster Than Forecast.

Earth’s Ice Is Melting Much Faster Than Forecast.

SOURCE: Garn Press DATE: February 5, 2018 SNIP: The key question, as I see it, is how to project what the sea level will soon be due to ice sheet melting. But this is confounded by us not really knowing what to expect. We keep being surprised by nature being more sensitive and complex. As the science develops, we see more interconnection, where multiplying feedbacks produce surprisingly fast responses. Will there be some saving self-regulation of human-induced climate warming and its melting land ice consequences? The enormous increase of heat in our oceans, from past decades of enhanced greenhouse effect, negates any hope that negative feedbacks or even solar output will prevent a much warmer world. The few negative feedbacks we have found for ice — like more snow as a result of a warming climate, more reflective frost, more efficient sub-glacial water transmission — are clearly being outdone. And at the global scale, despite some negative feedbacks like more clouds, clearly we are not seeing net cooling. Feedbacks, whether positive or negative, only do their thing after the initial effect. Negative feedbacks don’t reverse the perturbation. Seemingly the biggest issue with abrupt sea level rise comes from the now unstoppable loss of key sectors of west Antarctic ice and the discovery of more marine instability than we thought elsewhere. Like glaciers thinning rapidly in east Antarctica. Or in Greenland where improved bedrock maps reveal a marine connection an average of 40 kilometers further inland than previously thought. Or like how new fjord underwater mapping reveals greater fjord depths, increasing the odds that deep warm ocean water can communicate...
Stanford researcher: Interacting Antarctic glaciers may cause faster melt and sea level contributions

Stanford researcher: Interacting Antarctic glaciers may cause faster melt and sea level contributions

SOURCE: Stanford University DATE: January 23, 2018 SNIP: A new study shows that a large and potentially unstable Antarctic glacier may be melting farther inland than previously thought and that this melting could affect the stability of another large glacier nearby – an important finding for understanding and projecting ice sheet contributions to sea-level rise. The findings, by a Stanford-led team of radar engineers and geophysical glaciologists, came from radar data collected at the same locations in 2004, 2012 and 2014, each revealing details of the glaciers miles below the surface. The surveys show that ocean water is reaching beneath the edge of the Pine Island Glacier about 7.5 miles further inland than indicated by previous observations from space. The team also found that the Southwest Tributary of Pine Island Glacier, a deep ice channel between the two glaciers, could trigger or accelerate ice loss in Thwaites Glacier if the observed melting of Pine Island Glacier by warm ocean water continues down the ice channel. This new perspective on the Southwest Tributary shows melting beneath Pine Island may be currently or imminently causing the melting of Thwaites and speeding the rate of sea-level...
Unstable East Antarctic Ice Sheet Could Spell Catastrophe

Unstable East Antarctic Ice Sheet Could Spell Catastrophe

SOURCE: Truthdig DATE: January 14, 2018 SNIP: New research has confirmed one of the worst nightmares of climate science: the instability of the East Antarctic ice sheet. [R]esearchers have confirmed that one stretch of the southern polar coastline has melted many times in the past: by enough to raise sea levels by three to five metres. US scientists report in the journal Nature that they went to what they called the Sabrina Coast of eastern Antarctica to look for geological and geophysical evidence of change. Although the western region, and the Antarctic peninsula, is warming swiftly, for decades scientists have assumed that the great mass of ice in the eastern Antarctic was stable. But last year a research team looked more closely at meltwater flow from one of the region’s glaciers and concluded that it was not stable, and that any melting could result in a dramatic rise in sea levels. The latest study confirms that suspicion. “It turns out that for much of the East Antarctic Ice Sheet’s history, it was not the commonly perceived large stable ice sheet with only minor changes in size over millions of years,” said Sean Gulick, of the University of Texas Institute for Geophysics, one of those who led the study. “Rather, we have evidence for a very dynamic ice sheet that grew and shrank significantly between glacial and interglacial periods. There were also often long intervals of open water along the Sabrina Coast, with limited glacial influence.” And his co-author Amelia Shevenell from the University of South Florida said: “As ice melts, global sea levels rise. Most of Florida is at...