An international team of scientists has found that irreversible ice loss from Greenland and West Antarctica ice caps corresponding with out-of-control sea level rise may soon be imminent.
The study published in Nature communications warned that disaster is inevitable if the warming globe can’t stabilize below 1.8 celsius of preindustrial levels. Depending on the source, we are currently at a 1.3 or 1.2 Celcius rise in temperatures, which we are told is the safe level, according to the Paris Accords of 2015. It is likely that this summer, we will see the temperature rise to a catastrophic 1.5 Celcius, at least temporarily.
The Institute for Basic Science presser warns:
Melting ice sheets are potentially the largest contributor to sea level change, and historically the hardest to predict because the physics governing their behavior is notoriously complex. "Moreover, computer models that simulate the dynamics of the ice sheets in Greenland and Antarctica often do not account for the fact that ice sheet melting will affect ocean processes, which, in turn, can feed back onto the ice sheet and the atmosphere," says Jun Young Park, Ph.D. student at the IBS Center for Climate Physics and Pusan National University, Busan, South Korea and first author of the study.
Using a new computer model, which captures for the first time the coupling between ice sheets, icebergs, ocean and atmosphere, the team of climate researchers found that an ice sheet/sea level run-away effect can be prevented only if the world reaches net zero carbon emissions before 2060.
"If we miss this emission goal, the ice sheets will disintegrate and melt at an accelerated pace, according to our calculations. If we don't take any action, retreating ice sheets would continue to increase sea level by at least 100 cm within the next 130 years. This would be on top of other contributions, such as the thermal expansion of ocean water," says Prof. Axel Timmermann, co-author of the study and Director of the IBS Center for Climate Physics.
Ice sheets respond to atmospheric and oceanic warming in delayed and often unpredictable ways. Previously, scientists have highlighted the importance of subsurface ocean melting as a key process, which can trigger runaway effects in the major marine based ice sheets in Antarctica.
"However, according to our supercomputer simulations, the effectiveness of these processes may have been overestimated in recent studies," says Prof. June Yi Lee from the IBS Center for Climate Physics and Pusan National University and co-author of the study. "We see that sea ice and atmospheric circulation changes around Antarctica also play a crucial role in controlling the amount of ice sheet melting with repercussions for global sea level projections," she adds.
A torrent of trouble
Thus far, the global average sea level increased by one-fifth of a meter — roughly 8 inches — between 1901 and 2018, according to the WMO. Half of the sea-level rise to date is from thermal expansion, meaning that water expands as it grows warmer, and the other half is from melting glaciers and ice sheets.
The pace of ascending ocean levels is getting much faster. The average rate of sea-level rise went from 1.3 millimeters per year before 1971 to 1.9 millimeters per year between 1971 and 2006. Between 2006 and 2018, it rose 3.7 millimeters per year.
But that’s nothing compared with what’s in store. Due to the time lag between greenhouse gas emissions and global warming, and then between warming and glacial melting that causes the oceans to rise, humanity has already ensured that future sea-level rise will dwarf what has happened so far.
The WMO projects 3 to 5 feet of sea-level rise by 2100. “In less than 80 years, 250 million to 400 million people will likely need new homes in new locations,” U.N. General Assembly president Csaba Körösi noted in his remarks Tuesday morning.
Although nearly every nation agreed at the 2021 U.N. Climate Change Conference in Glasgow, Scotland, that limiting warming to 1.5°C is the goal, national pledges to reduce emissions put the world on pace for 2.2°C. And the policies actually in place point toward 2.7°C of warming by 2100.
That much warming would result in up to 20 feet of sea-level rise, the WMO reports. With that much increase, entire cities — including New Orleans and Miami — would be completely underwater. Even higher-elevation cities would face constant flooding and saltwater intrusion into their groundwater supplies.
The below “solution” to climate change tells us how truly boned we are.
The moonshot.
Proponents of a “moonshot” idea to deal with global heating have been handed a new, very literal, interpretation by researchers who have proposed firing plumes of moon dust from a gun into space in order to deflect the sun’s rays away from Earth.
The seemingly outlandish concept, outlined in a new research paper, would involve creating a “solar shield” in space by mining the moon of millions of tons of its dust and then “ballistically eject[ing]” it to a point in space about 1m miles from Earth, where the floating grains would partially block incoming sunlight.
“A really exciting part of our study was the realization that the natural lunar dust grains are just the right size and composition for efficiently scattering sunlight away from Earth,” said Ben Bromley, a theoretical astrophysicist at the University of Utah, who led the research, published in Plos Climate.
“Since it takes much less energy to launch these grains from the moon’s surface, as compared with an Earth launch, the ‘moonshot’ idea really stood out for us.”