Beyond Loss and Damage: A Theory of Change for the Post-2°C World

Why Mitigation, Adaptation, and Carbon Removal Are No Longer Enough

A note from the ARC team: Next week marks the 17th New York Climate Week, where thousands of leaders, funders, scientists, and advocates will gather to discuss climate action on the side of the UN General Assembly. In the run-up, we’re publishing a series of posts to share some of the work and ideas fueling the ARC initiative. This year in particular, we feel there is a moral imperative to shift the conversation to recognize the realities we now face and the change in approach needed to secure a safer future.

Put simply: the climate has entered a new era – one defined not only by rising emissions and adaptation needs, but by escalating risks of systemic breakdown. Rapid Arctic ice loss, collapsing glaciers, ocean current destabilization, and permafrost thaw are no longer blurry, distant possibilities; they are active processes that could lock in devastating cascading impacts, perhaps within a decade. Traditional pillars of climate action—mitigation, adaptation, and carbon removal—remain essential, but, regrettably, they are no longer sufficient on their own, and at any rate, are simply very unlikely to happen on the needed timescales.

It is time to re-focus the frame. That means accepting that catastrophic risks require their own strategies: dedicated research, prevention, and preparation. At ARC, our mission is to help build those options responsibly by advancing the science, communities, and institutional foundations that will allow society to act thoughtfully and effectively in the face of crisis, rather than turning to untested ideas out of desperation.

This first post introduces the case for prevention as a missing “fourth leg” of climate action, and previews some of the projects and ideas we’ll be highlighting throughout the week. We invite you to read, react, and join us in contributing to this effort and critical action space together. And if you’ll be in NY next week, let us know!

With that said, let’s dive in…

Cleaner Skies, Hotter Earth

In 2020, new shipping rules slashed sulfur pollution, clearing the skies of toxic particulates. A public health victory with an estimated 4,000 premature deaths¹ saved per year, yes. But also a climate shock. Those same particles had been reflecting sunlight into space. Their removal unleashed ~0.2 W/m² of additional heating, responsible for roughly 80% of the increase in Earth’s heat uptake since 2020. That’s equivalent to more than 3 years of additional global CO2 emissions, condensed into a sudden shock in 2020. This was a policy success turned planetary setback because no institution existed to connect scientific foresight, technological options, and governance when it mattered. And this was not an isolated case.

The entire tropospheric aerosol mask, formed by decades of coal burning, shipping, and industrial emissions, has been blocking roughly 0.5°C of warming all along. In effect, we have been running a form of solar geoengineering at a planetary scale, only in the most harmful, inequitable, and unplanned way imaginable: a byproduct of dirty energy rather than a deliberate strategy.

The Accountants of Apocalypse

The above story is a microcosm. A narrow policy win that, absent broader thought and planning, became a planetary setback. And this pattern is everywhere: our institutions have built a vocabulary for collapse, but almost no machinery for prevention. Loss and damage—the UN's official term for what can't be adapted to—translates, in practice, to civilizational triage. On paper, it's a ~$400 billion annual liability. In reality, its nations erased from maps, megacities displaced, food systems destabilized, communities broken, lives destroyed.

But the potential cascade is already in motion: Arctic summer sea ice may vanish by 2035, unleashing warming equal to decades of extra emissions. Greenland is losing ice mass fast enough to raise seas by a quarter-meter this century, disrupting storm systems in Europe and rainfall across Africa. Thawing permafrost releases methane that accelerates the warming that melts yet more permafrost. Acidifying and warming oceans erode the reefs that shield coasts from storms made stronger by sea-level rise. Each tipping element sets off the next in a chain we are only beginning to map, and could have escalating consequences of changes in the Earth system. This, in turn, could affect our ability to undertake work on environmental action that then destabilizes natural systems (derailment risk). And we've chosen to manage it as a bookkeeping exercise: a few billion pledged against trillions in projected loss. This is the real moral hazard.

The Fourth Leg: Prevention

The physics is pointing toward cascading failure; our response is bureaucracy, with loss and damage treated as a line item. Climate orthodoxy still rests on a three-legged chair: mitigation, adaptation, and carbon removal. To this, the UNFCCC has added a hollow fourth leg called loss and damage: cut emissions, adjust to changes, pull CO₂ from the air, and when that fails, attempt to compensate people and nations for irreversible impacts. The framework assumes we can tiptoe past thresholds through incremental progress. That assumption is obsolete. We are locked into dangerous warming even under optimistic scenarios, and the “smart money” on Wall Street is betting on +3 degrees C or more (but at least they’re very bullish on air conditioning stocks!). The challenge is no longer just cutting emissions or building seawalls. It is preventing Earth-system breakdown when natural regulation falters.

Which leads to an uncomfortable conclusion: our climate strategy is missing an entire dimension. Without a real fourth leg, the prevention of irreversible or cascading system failures, the chair cannot stand. Prevention demands a different logic: intervening before ice sheets disintegrate, before reefs bleach out, before permafrost feedbacks detonate.

And yet, the technologies that could address those dynamics directly, such as ocean alkalinity enhancement, solar reflection, targeted glacier stabilization, and reef cooling, are almost invisible in climate budgets. Renewables, by contrast, are a success story: global investment has grown from roughly $150 billion in 2005 to over $2 trillion in 2024, helping drive down costs and bend the emissions curve. That growth shows what is possible when capital, policy, and innovation align.

But other critical categories of catastrophic risk identification and prevention have seen nothing like this. Ocean alkalinity enhancement, capable of removing CO₂ at $40–200 per ton while buffering acidification, remains unfunded at scale. Solar reflection research has attracted only about $192 million in the past 15 years, even though stratospheric aerosols could offset a degree of warming for a few billion annually, around 25 times more cost-effective per degree avoided than renewables. Much is still unknown about the regional effects or unintended consequences, but that is precisely why the science must be funded and pursued.

The numbers become surreal when you look at Earth’s physical frontlines. The West Antarctic Ice Sheet, whose collapse could raise seas 3–5 meters, would impose $14 trillion a year in damages from just one meter of rise by 2100. Targeted interventions such as removing or refreezing the lubricating water under glaciers or reinforcing grounding lines are estimated at $20+ billion. At 2°C warming, 99% of coral reefs vanish, erasing ecosystems worth $2.7 trillion over 25 years, while pilot reef-cooling projects cost millions, not billions. The pattern is unmistakable: interventions that may be capable of shifting planetary outcomes for billions of people are starved of resources.

Building the Option Space for the Prevention of Catastrophic Climate Risk

The Advanced Research for Climate Emergencies mission is not to compete with mitigation, adaptation, or carbon removal, but to responsibly build options for the prevention of catastrophic system failures before it is too late. Without catastrophic risk prevention, we remain exposed to irreversible cascades such as ice sheets collapsing, permafrost releasing methane, and reefs disappearing that could overwhelm and, in fact, derail every other effort. ARC exists to ensure humanity has legitimate, scientifically validated options for managing these risks before crisis forces improvisation. That requires more than research papers: it means creating the knowledge, communities, and governance foundations that will allow governments and institutions to act responsibly if prevention becomes necessary. We see three strategies as essential to this work:

• Building the scientific knowledge base to test feasibility and safety

• Strengthening the community that can deliberate and act

• Preparing institutions so that options are available when choices can no longer be deferred

Building the Scientific Knowledge Base

Effective institutions cannot be built in a vacuum; they depend on a solid foundation of scientific knowledge. Without that foundation, governments will face planetary emergencies with no credible evidence to guide them, leaving only two bad options: react in panic, or fail to act at all. This is why ARC invests in small-scale, translational research that can prove or disprove the feasibility, safety, and efficacy of prevention options. The goal is not to rush deployment but to create the knowledge base that makes legitimate governance possible.

Some examples include ACER’s Arctic cloud-thinning work that targets feedbacks responsible for a quarter of global warming; proving it feasible could turn tens of millions in research into tens of trillions in avoided damages. The Undercurrent program’s microbubble pilots will cost a few million yet could preserve reef ecosystems worth trillions, while creating the policy framework for regional-scale protection. The Arete Glacier Initiative is testing interventions to slow West Antarctic collapse—where even a $20 billion effort with modest success would pay back easily >>1000x by avoiding sea-level rise measured in meters. And proposals to reflood inland depressions like Egypt’s Qattara Depression—capable of holding 1,000 cubic kilometers of water—could immediately lower global sea levels by millimeters, slow their rise by ~5%, and deliver cascading co-benefits in energy, restoration, and local development.

In each case, the purpose is not to guarantee success, but to establish a body of evidence that institutions can trust. By building this knowledge base now, ARC ensures that when tipping points approach, governments and multilateral bodies have options tested, risks understood, and pathways prepared.

Building the Community

Preventing catastrophic loss isn’t just a technical challenge; it’s a collective one. No single program, sector, or technology can safeguard the future on its own. What’s required is a community that can wrestle with differences yet still converge on the shared imperative: to avoid the loss of entire cities, coasts, breadbaskets, and cultures before it is too late.

ARC’s role is to help strengthen that community and center them as co-creators in shaping priorities, planning science, and executing programs. ARC funds communities on the frontlines: our current partners include Operaatio Arktis, a youth-led Arctic strategy initiative; the Green Africa Youth Organization, advancing equitable governance across six African nations; and Slum Dwellers International, linking over a billion people in informal settlements to global adaptation and risk mapping. We also support Generation Climate Europe, the continent’s largest youth-led coalition; the MENA Regional Climate Security Hub, amplifying voices from fragile regions through CGIAR; and the Arctic Youth Network, a youth-founded nonprofit elevating Indigenous perspectives. Together, these partners ensure that catastrophic-risk research is not just technically rigorous but socially grounded, so that the definition of what it means to prevent collapse, and the strategies for doing so, are shaped by those most exposed to risk.

Bridge to Institutions

For prevention to matter, it cannot remain the work of isolated labs or short-lived pilots. We need institutions that can advance, scale, and regulate across all four legs of the climate chair. Each of these domains requires long-term research, robust governance, and durable legitimacy. But prevention brings unique governing challenges: interventions that touch planetary systems, cross borders, and carry risks we are only beginning to map.

ARC’s role is not to build deployment machinery but to catalyze the science, translation, and institutional preparation that ensures legitimate options exist when governments must make hard choices. Today, our institutions are not ready. Internationally, there are no frameworks for authorizing interventions with cross-border consequences. Domestically, regulators lack the expertise to evaluate novel climate technologies, leaving them stranded in bureaucratic limbo. Media narratives, research incentives, and philanthropic portfolios all reinforce the same inertia. Without significant strengthening, we risk reaching moments of planetary emergency with nothing but panicked, fragmented responses that could deepen instability rather than resolve it.

Through the Climate Emergencies Forum (CEF) we bring together scientists, funders, policymakers, frontline communities, and industry leaders who would otherwise remain siloed. Convening these diverse stakeholders, embedding frontline perspectives, and co-developing safety protocols and institutional pathways is a form of governance preparation for risk reduction. The goal is to ensure society has credible, science-based, and socially grounded options, so that when political pressure collides with physical reality, we can act responsibly rather than improvising under duress.

The Institutional Tipping Point

Together, these strategies—technical derisking, community building, governance preparation—create the conditions for prevention: absorbing first-mover risk across all three domains so society can respond effectively when climate realities force institutional action. But conditions are not capacity. Unless we act in this decade, the politics will arrive too late, and interventions will remain unbuilt when they are needed most. By the time pressure builds for emergency action, we’ll be forced to choose between untested ideas and watching preventable catastrophes unfold.

At the moment, catastrophic-risk research is avoided by governments for political reasons, due to high uncertainty and controversial optics. And unlike conventional climate solutions, there is no market mechanism for Arctic cooling, AMOC stabilization, or permafrost protection; these are global public goods. It is also bypassed by most philanthropy because it falls outside conventional mitigation and adaptation portfolios. Climate philanthropy totals $10 billion a year, less than 1% of overall climate finance, and most of it follows mainstream priorities where marginal dollars add little against trillion-dollar flows. Where basic science does receive some support, almost no one funds the translational step: moving scientific insights into small-scale experiments that can prove or disprove safety and efficacy, and building the organizational and governance scaffolding that could one day allow adoption at scale.

We have been here before. In the 1990s, adaptation was seen as an admission of failure, until a handful of innovators advanced the science, built communities of practice, and connected to institutions, creating the foundations for what is now climate policy. In the 2000s, carbon dioxide removal was derided as a distraction; again, communities pushed forward with basic science, translational R&D, and coalition-building, so that when overshoot became unavoidable, CDR was ready to be pulled into climate strategy. That is the work now required for catastrophic-risk prevention. Unless someone funds the basic science, builds the community, and bridges to institutions, the options will not exist when we need them.

This is precisely the window for transformative philanthropy. Tens of millions now can generate the science and governance foundations that governments will later fund in the billions. Small grants enable world-class scientists to test neglected ideas; early governance work creates pathways so promising options don’t remain stranded in journals when they are most needed.

The real choice is not optimism versus pessimism, but preparation versus improvisation. Either we build response capacity while there is still time, or we scramble to invent it after Earth’s systems fail. The expertise exists. The pathways are visible. What’s missing is the will to act before prevention itself becomes impossible. We may have a decade to prove that catastrophic outcomes are not foregone tragedies. The question is not whether prevention is possible, but whether we will choose to seize it.

1. Its worth noting that this amounts to just 0.06% of the 7M people that die prematurely from air pollution each year, according to the WHO.