The rising sea-level has two sources: runoff from the land (mostly glacial melt water) and thermal expansion of the ocean itself due to warming from excess solar energy accumulating from the global warming process.
The melt water in the rising sea-level comes from two primary sources, melting glaciers and ice cap on Greenland that has increased 6-fold over the last couple of decades; and melting glaciers and ice cap on Antarctica which has more than doubled over the same time. This is measured by the loss of mass variable – representing the weight of the water that has been added to the oceans.
As described in the feature article below, the melting rate of a glacier is determined by its speed as it is creeping/sliding down the continental slope into the ocean. This in turn is determined by a complex set of interacting factors, e.g., temperature, angle of slope, width and roughness of the bed, how much meltwater is in the bed to lubricate/float the ice, where and how the ice may crack and crumble, how many bends there are in the valley, ocean conditions at the foot, whether and to what extent warm and salty (salt lowers the melting temperature of ice) ocean water penetrates into the glacier bed under its foot, thickness and extent of the floating ice shelf at the glacier’s foot and so on. Simply stated, melt rates are inherently unpredictable. However, one thing we can be sure of is that the melt rate will speed up as ambient temperatures increase the rate of ice melting, and rain replaces snow as the main form of precipitation.
The geological record provides good evidence that episodes of abrupt ice melting can cause raise sea-levels a lot faster than they are now, perhaps even showing large changes in rate over a few decades.
There may well be enough ice in the West Antarctic Ice Sheet — especially if combined with an equally rapid melting of the Greenland Ice Sheet to support an equivalent amount of melting to the Meltwater Pulse 1A. It is notable that the land surface underlying very large areas of both West Antarctica and Greenland are below sea level – giving ample opportunities for warm ocean water to help speed the melting and collapse of the ice sheets.
Why Melting Ice in Antarctica is Making Waves: Scientists recently discovered that the Thwaites Ice Shelf, a floating ice shelf that supports the Florida-sized Thwaites Glacier, could collapse in as little as five years because of global warming.
Climate Reality Project, 28/01/2022
This past December, the massive Thwaites Glacier in Western Antarctica made headlines for all the wrong reasons. Specifically, because new research revealed that the ice shelf preventing it from sliding into the ocean and drastically raising sea levels could collapse well within the next decade.
This Florida-sized glacier had already worried experts for years, going as far as to regularly be called the “Doomsday Glacier”. And yet, this update from the scientific community was still groundbreaking.
It’s news that the world — particularly low-lying island and coastal communities — should understand and act on. So, what exactly is Thwaites Glacier, what does the latest research about it say, and what consequences could come from its decline?
FIRST THINGS FIRST, WHAT IS THWAITES GLACIER?
Thwaites Glacier is a massive body of dense ice located in Western Antarctica. Measuring about 80 miles (120 km) across, it’s the widest glacier on Earth.
Thwaites Glacier in Western Antarctica. Credit: NASA
The glacier has an ice shelf — a permanent piece of floating ice connected to it — that branches out into the Amundsen Sea. Now, understanding what exactly an ice shelf does is crucial.
Read the complete article….
As long as the world continues to warm and large amounts of snow and ice remain lying on the land, sea levels will continue to rise. The risk of an abrupt sea-level rise is real. The human and economic costs of such an event would be catastrophic if it happens. It therefore makes very good sense that mitigation works should begin soon with planning in place at federal, state and local levels to accelerate the work if we have any clear early warning signs that abrupt melting is actually beginning.
Also, from the official transcript dated 20/12/2019 from the PM’s own office, Scotty made it abundantly clear to John Stanley on 2GB Radio that HE doesn’t fight fires… “But I know Australians understand… that, you know, I don’t hold a hose, mate, and I don’t sit in a control room. That’s the brave people who do that are doing that job. But I know that Australians would want me back at this time out of these fatalities. So I’ll happily come back [from his secret holiday in Hawaii] and do that.”
In other words, smell the smoke, see the reality, and fight the fire that is burning up our only planet so we can give our offspring a hopeful future. This is the only issue that matters. All Capt. Humbug and his troop of wooden-headed puppets are doing is rearranging the furniture in the burning house to be incinerated along with anything else we may care about. In Greta’s words, “even a small child can understand [this]”. People hope for their children’s futures. She doesn’t want your hope. She wants you to panic enough to wake up and fight the fire…. so she can have some hope for her future. Vote Climate One’s Traffic Light Voting System will help you use your vote wisely on behalf of our offsprings’ futures.
Views expressed in this post are those of its author(s), not necessarily all Vote Climate One members.
Part 3 of David Spratt’s guidebook to events along the road to Hothouse Hell: Collapse of the Greenland Ice Sheet.
Continuing from David Spratt’s look in Part 2 of his guidebook at evidence that the West Australian Ice Sheet is beginning to collapse; here, in Part 3 he turns his attention north, to signs that Greenland’s Ice Sheet is also beginning to collapse. As before, we are looking at the impacts of a probable sequence of events along the global warming road to Earth’s Hothouse Hell. These are leading us to what Steffen et al. described as the Earth System’s Hothouse (see the featured graphic above) in their 2018 Proceedings of the National Academies of Science paper, Trajectories of the Earth System in the Anthropocene. The potentially cascading impacts of these events were also summarized in Lenton et al’s 2019 comment paper in Nature, Climate tipping points — too risky to bet against. An additional danger is that these may also cascade rapidly to cause a large change abruptly. The bottom line is that if we cannot stop the warming and backtrack to a lower temperature world, we cannot avoid the Hothouse and the road will end in the mass extinction of most species of complex life on our only planet, including ourselves.
There is no evidence that anything other than a rapidly mobilized war effort by humans will stop the cascade passing the point of no return to runaway warming and global mass extinction. If we want to leave any kind of future to our children and grandchildren, we had better pay heed to the warning signs that Spratt is pointing out, and start mobilizing and acting NOW!
24 January 2022
Have tipping points already been passed for critical climate systems? (3) Greenland and the Arctic: Abrupt change
“The Arctic is screaming”, says Mark Serreze, Arctic climate expert at the US National Snow and Ice Data Center.
Arctic warming is racing ahead of the worst-case estimates, now heating four times faster than the global average, and the region is undergoing abrupt climate change, understood as a transition of the climate system into a different mode on a time scale that is faster than the responsible forcing. In other words, it has passed a tipping point for rapid, system-level change.
Researchers say that the Arctic “is currently experiencing an abrupt climate change event … climate models underestimate the abruptness of the recent changes observed in the Arctic (and) climate models underestimate this ongoing warming”. [Models do not account well for warming due to sea-ice loss, but losing the reflective power of Arctic sea ice in the summer months would advance the 2ºC threshold by 25 years”.]
Read the complete article…..
If we do nothing to stop the inexorable warming process we started with the proliferating carbon burning used to fuel the Industrial Revolution and our continuing competition to control the world the Climate System will complete its flip into Earth’s Hothouse Hell state. It will be very unlikely that we can avoid the hothouse and extinction along with the rest of the biosphere that supports our lives.
From the time the Abbott Government was elected in 2013 the LNP COALition Governments (currently under Capt. Humbug, (a.k.a. Scotty from Marketing) and his henchman Blarny Bulldust (The Man with the Hat) have worked hard to protect and and advance the interests of their patrons with special interests in the fossil fuel and related resource exploitation industries. Thus, for nearly a decade, The COALition’s humbug, denial, parliamentary blocking, disinformation, distraction and stupidity has successfully disrupted virtually every attempt to act against greenhouse gas emissions or even to slow the continued expansion of these lethal industries. Every year the COALition has been in power we are that much closer to the point of no return where our extinction is the only plausible outcome.
So what can Australians do to begin improving our odds to avoid the Hothouse Hell? One very obvious action is to replace the COALition government with people we can trust to put action on the climate emergency at the top of their goals in office and who have the capacity to organize and lead Australia’s mobilization of a global effort to stop and reverse global warming.