Abstract The Atlantic meridional overturning circulation (AMOC) is a major tipping element in the climate system and a future collapse would have severe impacts on the climate in the North Atlantic region. In recent years weakening in circulation has been reported, but assessments by the Intergovernmental Panel on Climate Change (IPCC), based on the Climate Model Intercomparison Project (CMIP) model simulations suggest that a full collapse is unlikely within the 21st century. Tipping to an undesired state in the climate is, however, a growing concern with increasing greenhouse gas concentrations. Predictions based on observations rely on detecting early-warning signals, primarily an increase in variance (loss of resilience) and increased autocorrelation (critical slowing down), which have recently been reported for the AMOC. Here we provide statistical significance and data-driven estimators for the time of tipping. We estimate a collapse of the AMOC to occur around mid-century under the current scenario of future emissions.
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The Earth is a complex system.
Warming is one aspect of climate change, but we'll likely see cascading effects in the system.
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For example, as global temperatures rise we are seeing that AMOC (Atlantic Meridional Overturning Circulation), and as a result the Gulf Stream, are "slowing down". [1]
This could result in EU cooling down.
The clathrate gun hypothesis suggests that large releases of methane could cause abrupt climate shifts due to methane’s strong greenhouse effect. [2]
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Its likely developing nations and their citizens will increase CO2 usage as they move towards a more western lifestyle.
That means there will be an increasing amount of energy production and usage.
Ideally we generate more with solar and nuclear.
Decreasing energy production and consumption is not a real solution.
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[1] https://www.nature.com/articles/s41467-023-39810-w
[2] https://en.wikipedia.org/wiki/Clathrate_gun_hypothesis
So Lisbon will finally become a replica of San Francisco... /s [0]
Basically, European cities will have similar weather to cities West of the Rockies. So London will share temperatures with Vancouver overtime, and Oslo with Anchorage.
It would be a massive regional climate catastrophe, but worst case, at least European countries are rich enough to support the infra changes needed.
Silver lining, it would create a West African monsoon that would restart Saharan greening and push back desertification in the Sahel, but would suck for Egypt as most of their wheat comes from Russia+Ukraine, which would have shorter sowing seasons, but then again their climate would change to…
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that of Southern Alberta+Saskatchewan.
But then again, might have positive effects for the Amazon [1]
Edit: that said, it appears that ICPC's AMOC model seems to have some issues with backtesting [2] All the more reason to err on the side of caution and ensure the status quo remains and the AMOC continues.
[0] - https://www.nature.com/articles/s41467-023-39810-w
[1] - https://www.nature.com/articles/s43247-023-01123-7
[2] - https://royalsocietypublishing.org/doi/10.1098/rsta.2022.019...
The study published today ("Physics-based early warning signal shows that AMOC is on tipping course"):
https://www.science.org/doi/10.1126/sciadv.adk1189
> They do not present a particular time period estimate for reaching the tipping point, as more observations of the ocean circulation at this latitude will be needed for that, but they note about last year’s Ditlevsen study that “their estimate of the tipping point (2025 to 2095, 95% confidence level) could be accurate.”
The Ditlevsen study ("Warning of a forthcoming collapse of the Atlantic meridional overturning circulation"): https://www.nature.com/articles/s41467-023-39810-w
The Fermi paradox is the conflict between an expectation of a high {\em ex ante} probability of intelligent life elsewhere in the universe and the apparently lifeless universe we in fact observe.
Despite their massive size, successful deep artificial neural networks can exhibit a remarkably small difference between training and test performance.
In honor of Alan Turing's hundredth birthday, I unwisely set out some thoughts about one of Turing's obsessions throughout his life, the question of physics and free will.