The Global Tipping Points Conference That Gave Geoengineering a Cool Reception

Two weeks ago, I spent four days at the Global Tipping Points conference in Exeter listening to scientists describe civilization-threatening catastrophes. The Amazon turning to savannah. The Atlantic circulation shutting down. Ice sheets collapsing irreversibly. Renowned planetary scientist (and co-convenor of the conference) Johan Rockström called it "global catastrophic risk," the kind that could kill 10% of humanity. The window to prevent these cascades? "Rapidly closing."

I enjoyed the conference and the scientific program immensely. However, it seemed to me like the solutions discussed on the panels and in the seminars focused almost exclusively on social transformations, such as behavior change, tougher policies, and even specific local acts like Danish plant-based communal dinners.

The Three-Legged Stool with a Missing Leg

I came to Exeter from the carbon removal world, where I'd spent years convinced that our society could both reduce and remove our way out of the climate crisis. But the math finally caught up with me. I no longer believe that those two efforts alone are enough to prevent catastrophic warming. Even our most optimistic projections show that emissions reduction still isn’t happening fast enough, and decades are going to be needed for carbon removal to scale up. These are decades we don't have before hitting those “unacceptable” global tipping points.

This realization has led me to a simple framework. We have exactly three tools to prevent warming-driven tipping points:

1. Emissions reduction and decarbonization

2. Carbon removal from the atmosphere and oceans

3. Cooling interventions (like stratospheric aerosol injection)

At a conference about preventing catastrophic tipping points, you'd expect serious discussion of all three. Instead, across four days, there was only one session on carbon removal and two brief talks on geoengineering buried within other sessions.

Moving Beyond Ideology When Managing Existential Risk

On day three, I spoke to a climate scientist during a break. I explained I'd come from carbon removal but was exploring geoengineering since CDR wouldn't scale fast enough to prevent tipping points. His response floored me: "You likely won't find support here. Geoengineering and carbon removal are just cover for the oil and gas industry."

I hadn't heard that argument about carbon removal in years. That view was common in the early 2010s, but since 2018, the IPCC has been clear that carbon removal is necessary for virtually every climate scenario. Anyone who understands our energy and food systems knows we can't possibly reduce emissions fast enough to meet UN carbon budgets without it (to say nothing of dealing with legacy emissions). Yet here was a climate scientist lumping established, IPCC-endorsed carbon removal with nascent geoengineering research. It crystallized what I'd been sensing: this wasn't technical skepticism. This was ideological bias.

During a plenary session, Oliver Morton from The Economist (speaking in personal capacity) finally said what I'd been thinking. He noted the massive 2023 tipping points report—nearly 500 pages on catastrophic risks—contained only a few paragraphs on solar radiation management. If we truly face civilization-threatening risks, why aren't we researching every option? He called it "choice editing": a small group deciding for humanity which solutions are acceptable to discuss.

Yes, Morton serves on the board of the Degrees Initiative, which funds SRM research in the Global South. But pointing out conflicts of interest doesn't make the question go away.

To be fair, I don't think the conference organizers themselves are opposed to researching a broad spectrum of interventions regarding the climate and other planetary crises. Science is built on critical examination, questioning and following the evidence where it leads. But based on the individual conversations I had, I think that there's an "unknown known" at play here—an unspoken rule that these topics are too controversial for the main stage. That cultural boundary might be more dangerous than any individual's ideology.

Two Worldviews at Risk of Diverging

The conference revealed something concerning: we risk splitting into two fundamentally different camps.

Camp 1 believes we must transform hearts and minds first. Change values, change policies, solve climate change. It's the COP approach, the activist approach, the "system change not climate change" approach. Their theory of change operates on generational timescales.

Camp 2 sees discrete technical problems requiring specific solutions. Emissions? Deploy renewable energy. Excess CO2? Remove it. Too much heat? Reflect some sunlight. Their theory of change operates on technological timescales.

In private conversations, I found most attendees genuinely thoughtful about needing both approaches. The disconnect between hallway conversations and plenary sessions was striking, suggesting the problem is more about cultural norms in the climate research community than individual closed-mindedness.

But here's the challenge: if we genuinely believe we're five to ten years from triggering irreversible tipping points, can we wait for social transformation alone? Are social interventions any less complex than physical interventions?

Don’t we need to start paying more attention to the full range of options available?

No Easy Interventions

I understand and share the concerns about solar geoengineering. The termination problem is real—stop reflecting sunlight suddenly and temperatures spike. Governance is a nightmare—who controls the global thermostat? Regional impacts could be severe—some areas might face droughts while others flood.

But let's apply the same scrutiny to social interventions. What happens if behavior change campaigns backfire and create further polarization and political instability? What are the termination effects if well-intentioned social movements become harmful and then collapse? Do the planetary science and sustainable development communities examine these questions with the same skepticism we apply to physical interventions?

The conference's own presentations showed what's at stake: the Amazon becoming permanent savannah, AMOC shutting down and destroying European agriculture, ice sheets crossing points of no return and causing catastrophic sea level rise for millions and maybe even billions of people.

Which risk portfolio is more dangerous—researching all options or limiting ourselves to social transformation alone?

Here's what I think drives the silence: scientists fear moral hazard above all else. Give fossil fuel companies any excuse to keep drilling and they'll take it. "Why cut emissions when we can just spray sulfur in the stratosphere?"

It's a legitimate fear. But it's also a privileged position. Easy to prioritize moral purity when you're not governing the Maldives or farming in Bangladesh, watching the water rise.

The Cost of Unspoken Rules

The mundane factors matter too. Research funding flows to established topics. Careers get built in accepted fields. Conferences develop cultural boundaries. Nobody wants to be the scientist advocating for the "dangerous" option, even when the alternative might be more dangerous.

But if we genuinely believe tipping points pose catastrophic risks—and the conference insisted we should—don't we have an obligation to research everything? To make all the “knowns” actually known? Not reckless deployment. Not giving up on emissions reduction. But serious research, modeling, and small-scale tests proportional to the risks we face.

I left Exeter energized by the brilliant science but frustrated by the invisible boundaries that parts of the academic community seem to be semi-consciously drawing. We're like doctors in an emergency room letting cultural taboos prevent us from discussing certain treatments while the patient deteriorates.

Where From Here?

The conference ended with urgent statements about "rapidly closing windows" and "catastrophic risks to billions." But our response doesn't match our rhetoric when we can't even openly discuss all options.

So where does someone like me contribute? The conversations I had with the few geoengineering researchers present suggested paths forward: monitoring systems, governance frameworks, bridging the camps. Maybe just having these conversations openly is a start.

The real enemy isn't Camp 1 or Camp 2. It's the polarization that prevents us from using every tool available. We need the complexity thinking that examines social interventions as rigorously as physical ones. We need conferences where discussing stratospheric aerosols is as acceptable as discussing Danish eating habits. We need an academic culture that matches the urgency of the crisis it documents.

Most importantly, we need to stop letting unspoken cultural rules edit our options when civilization is at stake.

If we're serious about preventing tipping points—truly serious—it's time to create spaces where all sincere solutions can be researched, debated, and refined. The people facing climate impacts don't care about our cultural or political boundaries. They care about survival.

The moral stakes can feel incredibly high for many people in this space. But moral certainty—whether about social transformation or technological fixes—won't cool the planet. Only honest and complex thinking, dialogue, networked innovation, and real consideration of all our options will deliver the positive tipping points that the near future so desperately needs.

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This is not really the next article in my global cooling series, and to be honest, I have become so interested in this topic that this newsletter is definitely going to spend more time on global cooling efforts in the future. I had a draft ready to go for the cooling ecosystem piece but decided to wait until I had attended the conference. I'm glad I did, because I learned an enormous amount, met some very smart and interesting people, and greatly enhanced my understanding of the current landscape. I am so glad I went and very appreciative to the organizers. But I also came away quite disappointed about the lack of interest and attention on cooling efforts. This was my debrief. Cooling ecosystem article will follow. And lest you think I've forgotten about carbon removal, fret not! More to come there too.