The main purpose of this ongoing blog will be to track planetary extreme, or record temperatures related to climate change. Any reports I see of ETs will be listed below the main topic of the day. I’ll refer to extreme or record temperatures as ETs (not extraterrestrials).😉
Main Topic: Sea Rise Now Inevitable from Greenland Melting, But How Much?
Dear Diary. The number one climate related issue in the news this week was the awful flooding in Pakistan. Longer term and probably even more troubling is news concerning Greenland, which would be a close number two.
Every few months we see more studies and increasing dire forecasts concerning the Earth’s cryosphere, or coverage of ice. The extent of this is a big factor controlling our climate. Obviously as Arctic and Antarctic ice melts, our seas will rise, threatening all coastal cities and infrastructure. Also, there will be more of a positive feedback as this process occurs, because a lower albedo of all white ice that coats the poles would increase so that there would be less reflected incoming solar radiation.
The latest findings concerning Greenland are quite dire. Here is a report from the Guardian:
Major sea-level rise caused by melting of Greenland ice cap is ‘now inevitable’
Loss will contribute a minimum rise of 27cm regardless of what climate action is taken, scientists discover
Major sea-level rise from the melting of the Greenland ice cap is now inevitable, scientists have found, even if the fossil fuel burning that is driving the climate crisis were to end overnight.
The research shows the global heating to date will cause an absolute minimum sea-level rise of 27cm (10.6in) from Greenland alone as 110tn tonnes of ice melt. With continued carbon emissions, the melting of other ice caps and thermal expansion of the ocean, a multi-metre sea-level rise appears likely.
Billions of people live in coastal regions, making flooding due to rising sea levels one of the greatest long-term impacts of the climate crisis. If Greenland’s record melt year of 2012 becomes a routine occurrence later this century, as is possible, then the ice cap will deliver a “staggering” 78cm of sea-level rise, the scientists said.
Previous studies have used computer models of ice cap behaviour to estimate future losses, but the physical processes are complex and this leads to significant uncertainties in the results.
In contrast, the study published in the journal Nature Climate Change used satellite measurements of ice losses from Greenland and the shape of the ice cap from 2000-19. This data enabled the scientists to calculate how far global heating to date has pushed the ice sheet from an equilibrium where snowfall matches the ice lost. This allowed the calculation of how much more ice must be lost in order to regain stability.
“It is a very conservative rock-bottom minimum,” said Prof Jason Box from the National Geological Survey of Denmark and Greenland (Geus), who led the research. “Realistically, we will see this figure more than double within this century.”
The 27cm estimate is a minimum because it only accounts for global heating so far and because some ways in which glacier ice is lost at the margins of the ice sheet are not included.
The advantage of this study is that it provides a solid estimate of inevitable sea-level rise but the method used does not give a timescale over which the ice will be lost. Nonetheless, based on scientists’ overall understanding of how sheets such as Greenland lose ice into the ocean, the researchers said most of the rise would occur relatively soon. In 2021, other scientists warned that a significant part of the Greenland ice sheet was on the brink of a tipping point.
“The minimum of 27cm is the sea-level rise deficit that we have accrued to date and it’s going to get paid out, no matter what we do going forward,” said Dr William Colgan, also at Geus. “Whether it’s coming in 100 years or 150 years, it’s coming. And the sea-level rise we are committed to is growing at present, because of the climate trajectory we’re on.”
Colgan said: “If  becomes a normal year, then the committed loss grows to 78cm, which is staggering, and the fact that we’re already flickering into that range [of ice loss] is shocking. But the difference between 78cm and 27cm highlights the [difference] that can be made through implementing the Paris agreement. There is still a lot of room to minimise the damage.”
Mountain glaciers in the Himalayas and the Alps are already on course to lose a third and half of their ice respectively, while the west Antarctic ice sheet is also thought by some scientists to be past the point at which major losses are inevitable. Warming oceans also expand, adding to sea-level rise.
“There is growing support in the scientific literature for multi-metre levels of rise within the next 100 to 200 years,” said Colgan. A collapse of the colossal east Antarctic ice sheet, which would lead to a 52-metre rise in sea levels if it all melted, could be averted if rapid climate action is taken.
Prof Gail Whiteman, at the University of Exeter, who was not part of the study team, said: “The results of this new study are hard to ignore for all business leaders and politicians concerned about the future of humanity. It is bad news for the nearly 600 million people that live in coastal zones worldwide. As sea levels rise, they will be increasingly vulnerable, and it threatens approximately $1tn of global wealth.” She said political leaders must rapidly scale up funding for climate adaptation and damage.
Here are some more “ET’s” and heavy precipitation notes recorded from around the planet the last couple of days, their consequences, and some extreme temperature outlooks:
Here is more climate and weather on my newsfeed from Tuesday:
(As usual, this will be a fluid list in which more information gets added during the day as it crosses my radar, crediting all who have put it on-line. Items will be archived on this site for posterity. In most instances click on the pictures of each tweet to see each article. The most noteworthy items will be listed first.)
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Guy Walton “The Climate Guy”