Ice loss from Canada’s Arctic glaciers has transformed them into a major contributor to sea level change, new research by University of California, Irvine glaciologists has found.
From 2005 to 2015, surface melt off ice caps and glaciers of the Queen Elizabeth Islands grew by an astonishing 900 percent, from an average of three gigatons to 30 gigatons per year, according to results published today in the journal Environmental Research Letters.
“In the past decade, as air temperatures have warmed, surface melt has increased dramatically,” said lead author Romain Millan, an Earth system science doctoral student.
The team found that in the past decade, overall ice mass declined markedly, turning the region into a major contributor to sea level change. Canada holds 25 percent of all Arctic ice, second only to Greenland.
Scientists have long viewed the Amundsen sea embayment as the Achilles heel of West Antarctica, with papers in the 1970s and ‘80s describing it as “uniquely vulnerable,” “unstable,” and the “weak underbelly” of the continent. The fear, then and now, was that warm ocean waters lapping against the foot of the glaciers could cause the ice to pop up off of its rocky floor, like ice cubes rising as a soft drink is poured into a glass. When ice detaches from its so-called “grounding line,” it kickstarts a chain reaction that can trigger a lot of melting.
“When water gets between ice and land, it moves quickly, bringing lots of heat in, and melting the ice above it more rapidly,” said Thomas Wagner, the director of NASA’s polar science program. “The Amundsen sea embayment is a place where we know this is happening.”
Indeed, satellite and radar data show that two of West Antarctica’s largest glaciers, Pine Island and Thwaites, have seen their grounding line retreat many miles since 2000, causing fresh water to pour off the ice and into the ocean. This process is so effective that glaciologists recently declared the total collapse of the Amundsen sea embayment—whose glaciers contain enough water to raise global sea levels by four feet—to be “unstoppable.”
New York Times / Justin Gillis / 03 September 2016
For decades, as the global warming created by human emissions caused land ice to melt and ocean water to expand, scientists warned that the accelerating rise of the sea would eventually imperil the United States’ coastline.
Now, those warnings are no longer theoretical: The inundation of the coast has begun. The sea has crept up to the point that a high tide and a brisk wind are all it takes to send water pouring into streets and homes.
Federal scientists have documented a sharp jump in this nuisance flooding — often called “sunny-day flooding” — along both the East Coast and the Gulf Coast in recent years. The sea is now so near the brim in many places that they believe the problem is likely to worsen quickly. Shifts in the Pacific Ocean mean that the West Coast, partly spared over the past two decades, may be hit hard, too.
Earth Institute Columbia University / James Hansen et al / 21 March 2016
Continued high fossil fuel emissions this century are predicted to yield: (1) cooling of the Southern Ocean, especially in the Western Hemisphere, (2) slowing of the Southern Ocean overturning circulation, warming of the ice shelves, and growing ice sheet mass loss, (3) slowdown and eventual shutdown of the Atlantic overturning circulation with cooling of the North Atlantic region, (4) increasingly powerful storms, and (5) nonlinearly growing sea level rise, reaching several meters over a time scale of 50-150 years. These predictions, especially the cooling in the Southern Ocean and North Atlantic with markedly reduced warming or even cooling in Europe, differ fundamentally from existing climate change assessments.
The Transition Towns movement aims toward veering away from excessive consumption – to deal with the conjoined problems of peak oil and climate change – but also in the belief that we may create an essentially more contented society, through building strong and resilient local communities. We will get to know our neighbours better, because we shall all need one another in the time to come.
So they go on in strange paradox, decided only to be undecided, resolved to be irresolute, adamant for drift, solid for fluidity, all-powerful to be impotent… Owing to past neglect, in the face of the plainest warnings, we have entered upon a period of danger…. The era of procrastination, of half measures, of soothing and baffling expedience of delays, is coming to its close. In its place we are entering a period of consequences…. We cannot avoid this period, we are in it now….