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: Climate Models Underestimate the Slowing of the AMOC
Dear Diary. Many of you following our changing climate are aware that freshwater melt flowing in from Greenland into the north Atlantic potentially could slow an important ocean phenomenon known as the Atlantic Meridional Overturning Circulation. As global warming increases melt water flowing into the Atlantic from Greenland will also increase, slowing the AMOC, which is crucial to keep Europe warm. Ironically, global warming could cool Europe, putting much of that area into a deep freeze affecting agriculture and harming millions.
A new study suggests that slowing of the AMOC has been underestimated by climate models. Many have thought that collapse of the AMOC would not happen until close to the 22nd century or not at all. Now it could happen withing a few decades. Chilling of Europe would be just one detrimental effect. Here are more details from LiveScience:
Key Atlantic current could collapse soon, ‘impacting the entire world for centuries to come,’ leading climate scientists warn
By Sascha Pare
published October 22, 2024
Leading climate scientists ring alarm bell on key Atlantic Ocean current collapse in open letter
Leading climate scientists signed an open letter warning about the collapse of the Atlantic Meridional Overturning Circulation (AMOC), which includes the Gulf Stream. (Image credit: NOAA)
Forty-four of the world’s leading climate scientists have called on Nordic policymakers to address the potentially imminent and “devastating” collapse of key Atlantic Ocean currents.
In an open letter published online Monday (Oct. 21), University of Pennsylvania climatologist Michael Mann and other eminent scientists say the risks of weakening ocean circulation in the Atlantic have been greatly underestimated and warrant urgent action.
The currents in question are those forming the Atlantic Meridional Overturning Circulation (AMOC), a giant ocean conveyor belt that includes the Gulf Stream and transports vital heat to the Northern Hemisphere. Research shows the AMOC is slowing down and could soon reach a tipping point due to global warming, throwing Earth’s climate into chaos.
“Such an ocean circulation change would have devastating and irreversible impacts especially for Nordic countries, but also for other parts of the world,” the scientists wrote in the letter. The Nordic countries include Denmark, Iceland, Norway, Finland and Sweden.
Related: Michael Mann: Yes, we can still stop the worst effects of climate change. Here’s why.
An AMOC collapse would lead to major cooling and extreme weather in Nordic countries, according to the letter. This would enlarge and deepen a strange “cold blob” that has already developed over the eastern North Atlantic due to the slowdown of heat-carrying currents. Collapsing ocean currents are also likely to precipitate climate impacts across the Northern Hemisphere, threatening agriculture in Northwestern Europe, according to the letter.
A map of the ocean currents in the Atlantic. (Image credit: Peter Hermes Furian via Shutterstock)
Other regions would feel the effects, too, the scientists said. Should the AMOC grind to a halt, it would trigger a southward shift in tropical monsoon systems — with catastrophic consequences for agriculture and ecosystems. Halted ocean currents could also further heighten sea levels along the American Atlantic coast and send marine ecosystems and fisheries into a state of “upheaval.”
Without urgent climate action, the AMOC could collapse in the next few decades, although there is huge uncertainty in predicting the timescales, according to the letter. The latest report by the Intergovernmental Panel on Climate Change (IPCC) states that “there is medium confidence that the Atlantic Meridional Overturning Circulation will not collapse abruptly before 2100,” but the scientists say this is an underestimate.
RELATED STORIES
—Gulf Stream’s fate to be decided by climate ‘tug-of-war’
The IPCC estimate is not only imprecise but also worrisome, according to the letter.
“The purpose of this letter is to draw attention to the fact that only ‘medium confidence’ in the AMOC not collapsing is not reassuring, and clearly leaves open the possibility of an AMOC collapse during this century,” the scientists wrote. “Even with a medium likelihood of occurrence, given that the outcome would be catastrophic and impacting the entire world for centuries to come, we believe more needs to be done to minimize this risk.”
The scientists addressed the letter to the Nordic Council of Ministers, an intergovernmental forum tasked with promoting cooperation among the Nordic countries. They urged policymakers to seriously consider the risks posed by an AMOC collapse and to increase pressure on international partners to stay close to the targets of the 2015 Paris Agreement, which aims to keep average global temperature rise to 2.7 degrees Fahrenheit (1.5 degrees Celsius) above preindustrial levels.
Trainee staff writer
Sascha is a U.K.-based trainee staff writer at Live Science. She holds a bachelor’s degree in biology from the University of Southampton in England and a master’s degree in science communication from Imperial College London. Her work has appeared in The Guardian and the health website Zoe. Besides writing, she enjoys playing tennis, bread-making and browsing second-hand shops for hidden gems.
More:
Here are more “ETs” recorded from around the planet the last couple of days, their consequences, and some extreme temperature outlooks, as well as any extreme precipitation reports:
Here is more brand-new October 2024 climatology (More can be found on each past archived daily November post.):
Here is More Climate News from Friday:
(As usual, this will be a fluid post 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.)