2050 Scenario? Atlantic Meridional Overturning Circulation (AMOC)

This follows on a map story here.  The next one is here.

After revisiting a number of topics for just over a year here, let's address an item of some urgency: stalling the Gulf Stream may end Western Europe's historic privilege; to be a warm enclave between two 'normal' bands at its latitudes. It's not an Ice Age but think how much colder New York and Montreal are than London or Paris. 

It may be hard to wrap our minds around cooling at a time where climate warming hits the headlines - and rightfully so -  and before climate deniers jump on this, please consult the scientific consensus behind all this under two Microsoft Copilot headings at the bottom: AMOC update, a political declaration of Nordic countries affected and estimated timeline of its collapse.

Update: AMOC collapse effect presented at the National Emergency Briefing last week in London here HT YouTube @JustHaveaThink

Current

Here is a world map with Climate Sub-Classes (aka. Koppen Climate Classification here). This contrasts the climate regimes on either side of the North Atlantic: while green classes match across South America & West Africa, Western Europe is a tan temperate enclave between cream & blues Eastern North America and Central / Eastern Europe. 

click to enlarge, full size here

That is because the Gulf Stream warms up Western Europe. The AMOC "conveyor belt" in red-to-blue  by ESRI's Witold Fraczek is added to illustrate this: the shallow red current swings northeast offshore Western Europe.

click to enlarge, full size here

Overlap

Let's take now the map from the 2nd Copilot entry at bottom, the declaration based on real data.

Even though their projections don't match, the Atlantic central portions allow reasonable overlay of the Annual Mean Average Temperature map from the scientists' declaration. It illustrates why we reached the tipping point of cooling waters that may stall the AMOC, due to the blue blob in the North Atlantic.

click to enlarge, full size here

Future

There follows a very simple paint-by-numbers exercise - no scientific modelling, just a picture to make the point - I translated the cold climate zones across Eastern North America to Western Europe. The absence of warm waters offshore either side is shown by purple replacing the red conveyor belt.

click to enlarge, full size here

Here is AMOC 2.0, Atlantic Meridional Overturned Circulation, est. to start as early as 2050. As mentioned, this is a simple illustration, not scientific research. 

click to enlarge, full size here

Note: let me point you to the Appendix of a previous synoptic view on climate change assessment here - I used to map flood risk in low-lying East Anglia, see my blog here as pertain to climate change here - where I point out that while temperature data are well constrained, time estimates are not! Again an illustration, not a scientific study. So even the 2050 date heard in the press is up for grabs. Please consult the science below...

Bonus

• future inset in current world @ 300 dpi Tabloid PNG here & 400 dpi TIFF here to make posters
• future inset in current world @ 300 dpi Tabloid SVG here & PDF here as special vector formats
• up-down current-future North Atlantic @ 300 dpi ANSI D PNG here & 400 dpi TIFF here, ditto
• GIF world here & N Atlantic here show Western Europe switch (may not work on all platforms)

All data and maps are CC BY-SA 4.0   so please re-use... For example, check out "Build your own maps" resources here!

---

Microsoft Copilot 18/11/2025:

Here’s the latest on the Atlantic Meridional Overturning Circulation (AMOC):
Recent studies show a clear slowdown trend in the AMOC, with mid-depth ocean warming in the equatorial Atlantic emerging as a reliable fingerprint of this weakening [1]. While some natural variability has temporarily offset anthropogenic weakening since the 2010s, the long-term risk of collapse remains a serious concern [2].

🌊 What Is the AMOC?

The Atlantic Meridional Overturning Circulation is a large system of ocean currents that transports warm, salty water northward in the upper layers of the Atlantic and returns colder, deeper water southward. It plays a crucial role in regulating climate, especially in Europe and the Arctic.

📉 Current Trends and Findings

• Mid-depth warming (1,000–2,000 meters) in the equatorial Atlantic has been identified as a key fingerprint of AMOC slowdown. This signal is more stable than surface indicators and correlates strongly with long-term AMOC weakening [1].
• A pause in weakening has been observed since the early 2010s, attributed to a tug-of-war between:
  • Anthropogenic forcing (e.g., greenhouse gases, reduced aerosols) driving weakening
  • Natural variability, especially a strong positive North Atlantic Oscillation (NAO), temporarily strengthening the AMOC [2].
• Despite this pause, the long-term trend remains downward, and the system is still considered vulnerable to tipping points.

🧭 Ongoing Monitoring and Initiatives

• The Joint Initiative on AMOC (2025–2027), led by JPI Climate and JPI Oceans, aims to produce an authoritative scientific review tailored to European and North American policy needs [3].
• This initiative complements IPCC assessments and emphasizes the urgency of coordinated international research and policy action.

---

Microsoft Copilot 18/11/2025:

click to enlarge, full size here

Open Letter by Climate Scientists to the Nordic Council of Ministers, Reykjavik, October 2024

You can access the original online posting of the October 2024 Open Letter by Climate Scientists to the Nordic Council of Ministers here (PDF).

This open letter was released during the Arctic Circle conference in Reykjavík and signed by 44 leading climate scientists from 15 countries. It urgently warns of the underestimated risk of a collapse in the Atlantic Meridional Overturning Circulation (AMOC)—a critical ocean current system that regulates climate across the North Atlantic and Arctic regions.

🔍 Key Highlights from the Letter

• Tipping Point Risks: The scientists emphasize that the AMOC is increasingly vulnerable to collapse, which could trigger abrupt and irreversible climate shifts, especially in Nordic countries [1].
• Scientific Consensus: Recent studies suggest the risk of AMOC collapse is higher than previously estimated by the IPCC, with potential impacts including regional cooling, extreme weather, and ecosystem disruption [1] [2].
• Call to Action: The letter urges the Nordic Council of Ministers to initiate a formal risk assessment and take proactive steps to mitigate this threat. It also calls for intensified global efforts to reduce emissions and stay within the 1.5°C target of the Paris Agreement [2].
• Presentation: The letter was formally handed to Iceland’s environment minister by Prof. Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research [2].

---

Microsoft Copilot 19/11/2025:

Under high-emission scenarios, the AMOC—including the Gulf Stream—could collapse after 2100, but some studies warn it might stall as early as 2025–2095. The risk is higher and more imminent than previously thought.

🌊 AMOC & Gulf Stream: What’s at Stake?

The Atlantic Meridional Overturning Circulation (AMOC) is a vast system of ocean currents that includes the Gulf Stream, transporting warm water northward and cold water southward. It regulates climate across Europe, the Arctic, and the tropics.

📉 Latest Projections and Timelines

• Potsdam Institute (2025): AMOC could shut down after 2100 under high-emission scenarios. This would drastically reduce northward heat transport, triggering extreme winters, summer droughts, and shifts in tropical rainfall belts.
• Utrecht University & KNMI (2025): Even under moderate warming (RCP4.5), AMOC weakening could lead to regional cooling in Europe, with Arctic sea ice expanding toward Britain, Scandinavia, and the Netherlands.
• University of Copenhagen (2023): A controversial study suggests AMOC collapse could occur between 2025 and 2095, far earlier than IPCC estimates. This is based on freshwater input from Greenland melt disrupting deep convection.

⚠️ Tipping Point Mechanism

• Collapse of winter convection in the Labrador, Irminger, and Nordic Seas is the likely trigger.
• Freshening of North Atlantic waters from rainfall and ice melt reduces salinity and density, weakening the sinking process that drives AMOC.
• Once vertical mixing fails, the system enters a feedback loop of decline.

🧭 What This Means for Europe

• Colder winters, even as the rest of the planet warms.
• Increased droughts and disrupted rainfall patterns.
• Expanded Arctic sea ice, potentially reaching Northwestern Europe.
• Ecosystem upheaval and intensified storms.