Beyond 1.5°C: When Warnings Become Reality

Iceland needs to prepare for climate tipping points

This week’s unprecedented heat wave in Iceland, shattering records by as much as 8°C, makes one thing clear: we have entered a new meteorological era. Yet, while extreme weather is now obvious to the public, the deeper reality remains poorly understood. We now face a fundamentally altered strategic reality due to the risk of catastrophic climate tipping points.

The planet is warming up, fast

The climate upheaval of the 2020s should not surprise us. Scientists have long warned of accelerating climate change. What is shocking is the pace at which conditions have deteriorated. We have already breached the critical threshold of 1.5°C warming, far ahead of schedule.

Five years ago, climate models projected we’d hit 2°C between roughly 2040 and 2070. The latest five-year predictions by the UK Met Office now suggest this threshold may arrive as soon as 2029. The leap from 1.5°C to 2°C is not incremental, it’s an exponential increase in global risk. Intensified storms, prolonged droughts, unprecedented heat waves, and devastating floods are already overwhelming regions globally.

Yet, extreme weather is just the visible tip of the iceberg. Beneath lies a much graver threat: climate tipping points. Tipping points occur when critical parts of the Earth’s climate system cross thresholds. A recent landmark study predicts that, on our current emissions trajectory (SSP2-4.5), there is at least a 62% chance of triggering tipping points, with nine distinct systems each surpassing a 50% risk threshold. Although great uncertainty remains, the scientific consensus increasingly views earlier risk assessments as dangerously conservative.

“For Iceland, this raises existential questions about habitability. Yet, the most terrifying aspect is not weather but the socioeconomic consequences.”

Tipping points involve self-amplifying feedback loops that push systems into irreversible states. Melting Arctic ice, for example, exposes darker ocean surfaces, absorbing more heat and further accelerating ice loss. Imagine pushing a kayak over the edge of a waterfall. Once you cross that point, paddling back is impossible. These tipping points ultimately risk triggering catastrophic events of such magnitude, they threaten the fundamental stability of human civilisation. Recent research presented at the 2025 Global Tipping Points Conference at Exeter University categorises five tipping point systems as global catastrophic risks, meaning they would each have devastating consequences on the lives of more than a billion people.

Yet, the North Atlantic might freeze over

Of particular concern is the Atlantic Meridional Overturning Circulation (AMOC), a vast ocean current system circulating warm water northwards and cold water southwards across the Atlantic, critical to stabilising Europe’s mild climate. Over the last five years, scientific literature on AMOC has grown significantly more pessimistic. Leading experts in tipping point science, such as Stefan Rahmstorf, now estimate a 50% probability that AMOC will cross its tipping point this century, a far bleaker outlook than the IPCC’s estimate just four years ago.

Recent headlines have highlighted dramatic weather implications of an AMOC collapse, including potentially catastrophic -50°C winter storms and sea ice towards the UK. For Iceland, this raises existential questions about habitability. Yet, the most terrifying aspect is not weather but the socioeconomic consequences. AMOC collapse would devastate global food production by radically altering precipitation patterns. An OECD report from 2021 predicts that nearly half of major global wheat and maize regions could become agriculturally unviable. Northern European agriculture is expected to fare even worse. It’s likely that such a shock would also have devastating impacts on North Atlantic fish stocks.

Today’s policies, based on outdated warming scenarios, are no longer adequate. The mindset that emissions reductions alone will suffice is obsolete. We have entered a starkly different climate reality and require policies reflective of this dangerous uncertainty. With the Paris-era playbook collapsing, we are left with only two fundamental levers: drastically deeper emission cuts and carbon removal on one hand, and direct climate intervention, the controversial option of deliberately cooling the planet, on the other.

I recently urged Iceland’s parliament to codify an obligation to protect citizens from unadaptable climate risk. My comments were intended as a wake-up call for policymakers. The comforting assumption that “everything will ultimately be fine” no longer holds. It is imperative to discard this illusion of safety and confront reality head-on.

What, then, should be done?

Firstly, emission reductions and carbon removal must accelerate far beyond current plans. But crucially, we must also establish comprehensive climate contingency governance. This means both emergency resilience measures to minimise unadaptable harm, and preparations for potential climate interventions.

Scientists are developing early warning systems (EWS) to predict imminent tipping points. Yet by the time warnings would arrive, traditional emissions cuts would likely be too late. More realistically, EWS might provide a crucial buffer for emergency preparations or deployment of climate interventions as last-ditch attempts to avert catastrophe.

“The comforting assumption that “everything will ultimately be fine” no longer holds.”

Recent modelling of climate interventions and the AMOC highlights a troubling fact that by the time we perceive things going wrong, crucial processes may have already ceased and may not be recoverable, even with emergency climate interventions. But we can act now. Research suggests proactive climate interventions initiated ASAP could be effective.

This creates a significant governance dilemma. Today, essential climate interventions still lack technological maturity and social acceptance. They require urgent investment and public support. We must overcome entrenched stigmas around climate interventions.

Our world has changed dramatically in just a few years. The pace of climate deterioration is accelerating far beyond our previous understanding. We must urgently adapt our strategies, policies, and societal mindset to this new climate reality, embracing proactive resilience and preparation for unprecedented, potentially catastrophic changes ahead. We’re setting up fire alarms, but we have yet to build any fire escapes.