As if we need more snarky news on how much apocalyptic trouble we are in, The Guardian chimes in and shares this feel-good story: How do you stop a glacier from melting? Simple – put up an underwater curtain.
John Gibbons asked nobody in particular, “Which stage of #collapse is passed when you reach the “let’s build a gigantic 100km (62 miles) underwater curtain attached to the sea bed to stop glaciers disintegrating” Phase?”.
Global heating stresses ecosystems, geological, atmospheric, ocean systems, and soil systems because more and more solar heat is absorbed by Earth instead of reflected into space. The world’s ice and the air conditioners for planet Earth are rapidly failing.
NASA’s vital signs of the Planet writes:
Earth is on a budget – an energy budget. Our planet is constantly trying to balance the flow of energy in and out of Earth’s system. But human activities are throwing that off balance, causing our planet to warm in response.
Radiative energy enters Earth’s system from the sunlight that shines on our planet. Some of this energy reflects off of Earth’s surface or atmosphere back into space. The rest gets absorbed, heats the planet, and is then emitted as thermal radiative energy the same way that black asphalt gets hot and radiates heat on a sunny day. Eventually this energy also heads toward space, but some of it gets re-absorbed by clouds and greenhouse gases in the atmosphere. The absorbed energy may also be emitted back toward Earth, where it will warm the surface even more.
Antarctica’s dry valleys and mountains were not always dry. Fourteen million years ago, the valleys were wet, reports Victoria University of Wellington — Herenga Waka, lecturer and Permafrost Geo chemistry, Dr. Marjolaine Verret. He found… “evidence that liquid water, the base requirement for life, persisted there for much, much longer—up to about six million years ago." The dry valley temperatures are the coldest on earth but were not always so: they were “once warm and wet enough to support liverworts, mosses, and shrubby trees."
"Our study provides strong evidence that the climate in the Valleys did not remain stable during this time. We found that water infiltrated the ground until the late Miocene, much later than previously suggested, and the Valleys shifted in intervals between a warm-wet climate and the dry polar aridity we recognize today."
That frozen vegetation is now giving back to the atmosphere CO2 and other gases likely from faults and cracks can release carbon dioxide together with significant “concentrations of methane helium at the base of the active layer, and used statistical methods to estimate CO2 emissions of 15 tonnes per day from the area, which is 1 or 2 orders of magnitude higher than the values found by the few previous studies.”
From the Journal Nature:
Many studies conducted in the North Pole region have revealed that the stability of permafrost — ground that remains at 0 °C or below for at least two years — plays an essential role in the carbon cycle, by determining how much carbon is released into the atmosphere instead of remaining trapped in the soil. However, very little is known about the release of greenhouse gases from the Antarctic permafrost. A team led by Livio Ruggiero and Alessandra Sciarra, from Italy’s Institute for Geophysics and Volcanology, decided to investigate.
In the southern hemisphere, permafrost soils are found at high elevations in the Sub-Antarctic islands, in the Antarctic Peninsula, and in the ice-free areas of the Antarctic continent. “The majority of previous studies focused on the Antarctic peninsula, but very few were done on the continent,” says Sciarra. During the Austral summer 2019–2020, the team measured the concentrations of soil gases (including carbon dioxide, methane, helium and hydrogen) and the flux of CO2 at the interface between the permafrost and the soil layer above it, called the active layer, over an area of more than 20 km2. The area is in the Taylor Valley, the southernmost of the three large McMurdo Dry Valleys in the Transantarctic Mountains, the largest ice-free region in Antarctica.
The scientists are still unsure about the mechanisms responsible for this gas release. Permafrost is generally a barrier to the movement and escape of gases, but underground faults and fractures can lead to surface gas anomalies with higher concentrations than deeper ones. Measuring gas emissions from the soil can create a map of such faults and fractures, and this is the first time that this method has been applied in Antarctica, in particular, it is the first time that scientists measure the distribution of gases over a large area rather than at a specific point and time. “The more you have a homogeneous spatial distribution and the larger the area covered, the more it is possible to understand if there is degassing or not, where the gas is released and whether there is a linked presence of faults,” adds Sciarra.
Currently stable parts of East Antarctica may be closer to melting than anyone realized
In a paper published Jan. 19 in Geophysical Research Letters, researchers at Stanford have shown that the Wilkes Subglacial Basin in East Antarctica, which holds enough ice to raise global sea levels by more than 10 feet, could be closer to runaway melting than anyone realized.
“There hasn’t been much analysis in this region – there’s huge volume of ice there, but it has been relatively stable,” said Eliza Dawson, a PhD student in geophysics at Stanford and first author on the paper. “We’re looking at the temperature at the base of the ice sheet for the first time and how close it is to potentially melting.”
The Wilkes Subglacial Basin is about the size of California and empties into the Southern Ocean through a relatively small section of the coastline. Dawson and her colleagues found evidence that the base of the ice sheet is close to thawing. This raises the possibility that this coastal region, which holds back the ice within the entire Wilkes Subglacial Basin, could be sensitive to even small changes in temperature.
Previous research has shown that, because the ground in this region is below sea level and slopes downward away from the ocean, the Wilkes Subglacial Basin could be particularly vulnerable to irreversible melting if warming seawater were to get under the ice sheet. Dawson and her colleagues are the first to look at how the current temperature at the base of the ice sheet in the region could add to this vulnerability.
The researchers found large areas of frozen and thawed ground interspersed across the region, but the majority of the area couldn’t be definitively classified as one or the other. In some cases, this may be because of changes in the geometry of the ice sheet or other complications in the data, but it could also mean that large sections of ground under the ice sheet are either close to thawing or made up of closely intermixed frozen and thawed areas. If the latter is true, the glaciers in the Wilkes Subglacial Basin could reach a tipping point with only a small increase in temperature at the base of the ice sheet.
“This suggests that glacial retreat could be possible in the future,” Dawson said. “This part of East Antarctica has been largely overlooked, but we need to understand how it could evolve and become more unstable. What would need to happen to start seeing mass loss?”
The analysis of ice cores provided the first concrete evidence that the West Antarctic Ice Sheet suffered rapid ice loss around the end of the Last Ice Age. New research shows that ice sheet coverage dramatically decreased around 8,000 years ago.
The data show that the ice sheet in one specific location decreased significantly by 450 meters (1,476 feet) within 200 years. According to a press statement, 450 meters exceeds the height of the Empire State Building.
Current projections for rising sea levels are between three and ten feet by the end of the century. We do not have to wait two hundred years for rising seas to ruin our civilization; salt water will infiltrate aquifers and poison freshwater availability around the heavily populated coastlines of the Planet. Infrastructure such as roads, airports, freshwater delivery systems, sewage systems, internet cable, and ports could all be inundated quickly if just one glacier in West Antarctica collapsed; Thwaites holds two feet of sea level rise alone, and it is highly vulnerable to warming undercutting stability below the surface. The Eastern Twaites Ice Shelf crumbles quickly despite being stuck on a sea mountain. Here is something that I have thought of recently: it will take less ocean warming and pressure from strong currents and gyres to move the ice off a mountain instead of ice still anchored to the bedrock. (thoughts?)
Ice cores had determined that West Antarctica rapidly collapsed 8,000 years ago when the climate was cooler than today. It was researched at the Ronne Ice Slelf and not Thwaites, as data is unavailable.
Interesting Engineering continues:
Scientists believe thinning was probably triggered by warm water getting underneath the edge of the West Antarctic Ice Sheet (a process currently underway across the continent), which normally sits on bedrock.
In 2019, scientists from the University of Cambridge and the British Antarctic Survey recovered a 651-meter-long ice core from Skytrain Ice Rise, which is located inland of the Ronne Ice Shelf in Antarctica. They transported the ice core to Cambridge for detailed measurement and study.
"We wanted to know what happened to the West Antarctic Ice Sheet at the end of the Last Ice Age, when temperatures on Earth were rising, albeit at a slower rate than current anthropogenic warming," said Isobel Rowell, study co-author from the British Antarctic Survey, in a press statement.
The British Antarctica Survey explains the ice core:
Ice cores are made up of layers of ice that formed as snow fell and was then buried and compacted into ice crystals over thousands of years. Trapped within each ice layer are bubbles of ancient air and contaminants that mixed with each year’s snowfall — providing clues as to the changing climate and ice extent.
The researchers drilled a 651m long ice core from Skytrain Ice Rise in 2019. This mound of ice sits at the edge of the ice sheet, near the point where grounded ice flows into the floating Ronne Ice Shelf. After transporting the ice cores back to Cambridge at -20oC, the researchers analysed them to reconstruct the ice thickness. First, they measured stable water isotopes, which indicate the temperature at the time the snow fell. Temperature decreases at higher altitudes (think of cold mountain air), so they were able to equate warmer temperatures with lower-lying, thinner ice.
They also measured the pressure of air bubbles trapped in the ice. Like temperature, air pressure also varies systematically with elevation. Lower-lying, thinner ice contains higher pressure air bubbles.
These measurements told them that ice thinned rapidly 8,000 years ago.
Antarctica’s Ocean Acidity Set to Rise Rapidly by Century’s End
Even the cold, remote waters of Antarctica are no refuge from ocean acidification. Acidity in some places in the ocean around Antarctica could double compared to 1990 levels by the end of the century, according to new research. Even if emissions don’t continue their steep rise, ocean acidity is likely to be significantly higher on the Antarctic shelf than it is today, threatening many of the organisms that live there.
When ocean waters absorb carbon dioxide (CO2), their pH level goes down, meaning acidity increases. Although ocean acidification is a threat to waters worldwide, there hasn’t been a scientific consensus on how it might affect Antarctic continental shelf waters, which are largely covered by massive ice sheets. The new research, published in Nature
As acidity rises, levels of calcium carbonate in seawater decline, and marine organisms that build shells begin running out of material. The more acidic waters will also begin eating away at their shells, forcing the organisms to expend more energy to maintain them.
Acidity levels can affect nonshelled creatures as well, ratcheting up stress levels and disrupting their reproduction and development, especially when combined with other factors like warmer waters, pollution, and overfishing. For example, a study of Antarctic krill, a foundational component of the continent’s oceanic food web, showed that metabolism increases as acidity rises. Another study showed that the combination of temperature increases and acidification harms developing dragonfish.
“We know what ecosystem stressors matter. And we know that ocean acidification is a big one that the organisms care about,” Nissen said.