Guest essay by Eric Worrall
According to Niklas Boers of the Potsdam Institute, if we don’t curb global warming, a large scale “Day After Tomorrow” style cooling event could strike in as little as two decades.
Climate crisis: Scientists spot warning signs of Gulf Stream collapse
A shutdown would have devastating global impacts and must not be allowed to happen, researchers say
Environment editor @dpcarrington
Fri 6 Aug 2021 01.08 AEST
Climate scientists have detected warning signs of the collapse of the Gulf Stream, one of the planet’s main potential tipping points.
The research found “an almost complete loss of stability over the last century” of the currents that researchers call the Atlantic meridional overturning circulation (AMOC). The currents are already at their slowest point in at least 1,600 years, but the new analysis shows they may be nearing a shutdown.
Such an event would have catastrophic consequences around the world, severely disrupting the rains that billions of people depend on for food in India, South America and West Africa; increasing storms and lowering temperatures in Europe; and pushing up the sea level in the eastern North America. It would also further endanger the Amazon rainforest and Antarctic ice sheets.
The complexity of the AMOC system and uncertainty over levels of future global heating make it impossible to forecast the date of any collapse for now. It could be within a decade or two, or several centuries away. But the colossal impact it would have means it must never be allowed to happen, the scientists said.
“The signs of destabilisation being visible already is something that I wouldn’t have expected and that I find scary,” said Niklas Boers, from the Potsdam Institute for Climate Impact Research in Germany, who did the research. “It’s something you just can’t [allow to] happen.”
Read more: https://www.theguardian.com/environment/2021/aug/05/climate-crisis-scientists-spot-warning-signs-of-gulf-stream-collapse
The abstract of the study;
Observation-based early-warning signals for a collapse of the Atlantic Meridional Overturning Circulation
Published: 05 August 2021
Nature Climate Change volume 11, pages 680–688 (2021)Cite this article
The Atlantic Meridional Overturning Circulation (AMOC), a major ocean current system transporting warm surface waters toward the northern Atlantic, has been suggested to exhibit two distinct modes of operation. A collapse from the currently attained strong to the weak mode would have severe impacts on the global climate system and further multi-stable Earth system components. Observations and recently suggested fingerprints of AMOC variability indicate a gradual weakening during the last decades, but estimates of the critical transition point remain uncertain. Here, a robust and general early-warning indicator for forthcoming critical transitions is introduced. Significant early-warning signals are found in eight independent AMOC indices, based on observational sea-surface temperature and salinity data from across the Atlantic Ocean basin. These results reveal spatially consistent empirical evidence that, in the course of the last century, the AMOC may have evolved from relatively stable conditions to a point close to a critical transition.
Read more (paywalled): https://www.nature.com/articles/s41558-021-01097-4
Sadly Boers’ study is paywalled, which I find a little surprising.
I mean if you wanted to warn people about an imminent comet strike, would you charge money for people to read your warning, or would you forget self interest and try to spread the news as far and fast as possible, in the hope of producing a response?
So why would anyone charge money for people to see their warning about what they claim is an imminent global climate catastrophe?