ClimateEdict #2: AMOC Collapse Risks, Geothermal Push, and UN Warnings
Opening Reflection
Nature is more fragile than most people realize. Remove a single predator and entire food webs can collapse. Change the balance of atmospheric gases and the climate system responds with rising temperatures and shifting weather. These are no longer abstract warnings. They are processes we’ve set in motion.
In 2025 there has been progress. Some governments and companies have adopted strategies to reduce harm, but many others continue to drive long-term damage. The larger problem is awareness. Many of the pressures on ecosystems and the climate go unnoticed by most people. If they aren’t recognized, they can’t be prevented.
That is why I started this blog. I care deeply about the climate and the ocean, and I could not sit back while these pressures grow. Each week I cover important climate stories tied to the ocean, breaking down the data and adding my perspective. Reports show part of the truth. The rest depends on what we notice, what we understand, and what we are willing to act on.
Atlantic Current Collapse No Longer “Low Risk”
For decades scientists warned that the Atlantic Meridional Overturning Circulation (AMOC), the system that carries warm water north and drives much of Earth’s climate, could collapse. It was often treated as a remote possibility. New research shows it is not.
A study in Environmental Research Letters concluded that the tipping point making an AMOC shutdown inevitable is likely to be passed within the next few decades. The collapse itself may take 50 to 100 years, but once the threshold is crossed, the outcome cannot be reversed.
The models are sobering. If emissions stay high, 70% of scenarios end in collapse. With moderate cuts, the risk is 37%. Even with low emissions, there is still a one-in-four chance. Stefan Rahmstorf, a leading oceanographer, said plainly: “Even in a low-emission scenario, sticking to the Paris agreement, the risk may be 25%. That is far too high.”
The consequences would be enormous. Europe could face colder winters and summer droughts. The tropics would see rainfall shifts that threaten food systems for millions. Sea level rise could accelerate by half a meter. The ocean conveyor belt that stabilizes the climate would instead destabilize it.
I think about what this means in practice. Divers already notice changing currents and disrupted migration. These shifts may look small, but they are early signs of a much larger breakdown. The ocean is warning us. The question is whether we act before the tipping point is locked in.
UK’s Oil and Gas Gamble
In Aberdeen this week, UK Conservative leader Kemi Badenoch pledged to “get all our oil and gas out of the North Sea” and to remove net zero requirements for drilling. It is a sharp reversal from climate commitments written into law just six years ago.
The argument is framed around energy bills and economic security. But government data shows new drilling will not lower costs for households. It will lock in emissions instead. The International Energy Agency and the UK’s Climate Change Committee have both said that new exploration undermines the Paris Agreement goal of keeping warming below 1.5°C.
Industry groups argue that North Sea production is “responsible” and better than imports. But this ignores the bigger picture: extraction adds to global supply, and emissions from burning the fuel are the same wherever it comes from. Other parties, from Labour to the Greens, called the policy reckless, noting that 2024 was already the first year global temperature averages rose more than 1.5°C above pre-industrial levels.
When I read these pledges, I see a gap between politics and science. The ocean and the climate are already under visible stress. Choosing maximum extraction now means adding to risks we already know are too high.
The Ancient Oxygen Flood That Changed the Seas
Nearly 390 million years ago, the deep ocean became permanently oxygenated for the first time. A study from Duke University shows that the spread of woody plants on land released enough oxygen to flood into the oceans, reshaping evolution.
This event unlocked new habitats. Jawed fish, ancestors of most vertebrates alive today, began colonizing deeper waters. Fossils show animals also grew larger, likely because higher oxygen supported greater metabolic needs.
Scientists established the timing of this change by analyzing selenium isotopes in rocks from five continents. Their results point to two events: a temporary pulse during the Cambrian, and then the permanent “oxygen flood” in the Devonian. The second event still defines ocean chemistry today.
Why does this matter now? Because the balance that took millions of years to establish can be disrupted in decades. Dead zones caused by nutrient runoff already show how fragile ocean oxygen is. I think about that when diving: a few meters down, oxygen is the difference between reefs bursting with life and places where nothing moves. This ancient story is not just history. It is a reminder of what we stand to lose if we let oxygen decline again.
Colorado’s Geothermal Transition
In the small town of Hayden, Colorado, a coal-fired power plant is shutting down. To fill the gap, the town is building one of the first geothermal heating and cooling networks in the western US.
Bedrock Energy, a drilling startup, is boring 1,000-foot wells that will connect to business park buildings. By using steady underground temperatures, the system can heat in winter and cool in summer with far less energy than conventional methods.
State leaders see it as a model. Colorado has set a goal of cutting electricity-sector emissions by 80% by 2030. Geothermal could play a major role because it runs day and night, unlike solar and wind. Utility companies are also watching closely as they face pressure to reduce grid stress from data centers and extreme weather.
For a community of just 2,000 people, the project is about survival. Losing coal means losing tax revenue and jobs. Geothermal offers a path to keep both while reducing emissions. It is an example of climate transition in practice: local choices that prepare communities for a different energy future.
Coming Up
Next week may bring Brazil’s Senate vote on environmental licensing, new NOAA data on ocean acidification, and early signals from Pacific governments on fisheries policy.
I appreciate you taking the time to read through this. Writing these updates helps me follow the science and policy more closely, and I hope it helps you as well. I’ll be back next week with more on where the ocean stands.
Sources
- Rahmstorf, S. et al. Shutdown of northern Atlantic overturning after 2100 following deep mixing collapse in CMIP6 projections. Environmental Research Letters, 2025.
- Explained Desk. Collapse of critical Atlantic current is no longer low-likelihood. Indian Express, 2025.
- Carrington, D. Collapse of critical Atlantic current no longer low-likelihood, study finds. The Guardian, 2025.
- BBC News. Tories pledge to get all oil and gas out of North Sea. 2025.
- Duke University. Ancient oxygen flood that forever changed life in the oceans. Proceedings of the National Academy of Sciences, 2025.
- Kipp, M. et al. Ancient forests fueled oxygenation of the deep ocean. Duke University / PNAS, 2025.
- Inside Climate News. A geothermal network in Colorado could help a rural town diversify its economy. 2025.
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