Article by Eric Worrell
Two for the price of one? As the ice melts, it will become very cold.
Climate change is the worst. That’s how bad it is this year.
Hannah Osborne
The big news in earth science this year has been about climate change, a warming climate that is causing extreme weather, floods and droughts. Scientists also warn that the situation will be worse if we don't control carbon emissions.
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The looming destruction of climate change
But some of the scariest news about the planet isn't what happened this year, but what might happen if we don't stop pumping carbon into the atmosphere. A study published in June Suggested ecological tipping points – e.g. Greenland ice sheet collapses and Amazon rainforest transformed into savanna – It will only take 15 years to achieve this if climate change is not controlled.
In October, scientists wrote an open letter warning Risks from the collapse of major Atlantic currents. Researchers urge policymakers to address threats posed by virus in report Atlantic Meridional Overturning Circulation (AMOC) weakens — A giant ocean conveyor belt transporting heat to the Northern Hemisphere, and its breakdown It could cause temperatures to plummet across Europe.
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Read more: https://www.livescience.com/planet-earth/climate-change-is-the-worst-heres-just-how-bad-it-got-this-year
My question is, how did the collapse of the Greenland ice sheet and the weakening of the AMOC happen at the same time?
If the AMOC weakens, will this slow the transfer of heat to Greenland?
I followed a study purportedly predicting the collapse of the Greenland ice sheet, which seemed less clear-cut than LiveScience described it. The study mentions the collapse of the Greenland ice sheet as one of a series of unstable climate events that the authors believe may begin to occur sometime between 2035 and 2047, but does not seem to give a clear date for the collapse.
Release date: June 22, 2023
Early collapse of Anthropocene ecosystems driven by multiple, faster, noisier drivers
natural sustainability Volume 6pp. 1331–1342 (2023) Cite this article
abstract
A major concern for the world's ecosystems is the possibility of collapse, a sudden change in the landscape and the societies it supports. Rising stress levels, increased frequency of extreme events, and strengthened connections between systems indicate that traditional modeling approaches based on single incremental changes in stress may not accurately estimate the impacts of climate and human activities on ecosystems. We conducted experiments on four models simulating sudden changes in Chilika Lagoon fisheries, Easter Island communities, forest dieback, and lake water quality—representing ecosystems with a range of anthropogenic interactions. Collapse occurs faster at increasing principal stress levels, but additional stresses and/or noise in all four models bring collapse significantly closer to today's conditions, about 38-81%. We discuss implications for further research and the need for humans to remain alert to signs that ecosystems are degrading faster than previously thought.
Learn more: https://www.nature.com/articles/s41893-023-01157-x
Another problem is that the claims that the AMOC is about to collapse and that the Greenland ice sheet is about to collapse at the same time seem inconsistent. If the tropics are overheated, then regardless of any salinity issues on the cold side of the engine, the hotter tropics will certainly enhance the AMOC pump by increasing the temperature difference that powers the heat engine. However, a slowdown in the AMOC should slow the flow of heat to Greenland, reducing melting rates.
Even if the AMOC collapse does coincide with the melting of Greenland's massive ice sheet, how quickly do they expect that mile-thick ice sheet to melt?
I bought too much milk a week ago, so I put a 6-pint plastic container of milk in the refrigerator. Yesterday I took the milk out of the refrigerator. That glass of milk that had been sitting on my kitchen counter all day yesterday still had a chunk of ice in it. My house is fairly warm and the air conditioning struggles in the hot subtropical Australian summer. Of course, I blame global warming, which is definitely not my fault for not investing in a larger air conditioner.
Obviously, if I put milk under a stream of hot water, the milk will melt faster, but if the AMOC collapses, less “warm” water will be delivered to Greenland.
Of course, we still have a long way to go to see if these predictions hold true. According to the above study, disasters like the collapse of the Greenland ice sheet are not expected to start happening until 2035 to 2047.
Pushing back start dates is nothing new in climate science, climate catastrophes, a bit like nuclear fusion, are always 10+ years in the future, unless they're trying to hype up some contemporary photogenic weather catastrophe.
Scientists wounded by overly aggressive ice melt predictions often seem to gracefully retire or otherwise fade into the background, or if they want to keep playing, they tend to push the date of updated disaster predictions to a safe distance in the future.
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