HothouseEarth

STRATEGIC FORESIGHT FOR SUCCESSFUL NET-ZERO TRANSITIONS

Hothouse Earth

Environmental tipping points could fuel a climate catastrophe POSSIBLE 2030-2050 DISRUPTION The planet crosses multiple, cascading tipping points, entering a “hothouse Earth” scenario. Dangerous warming is inevitable regardless of human action to reduce emissions. Deadly heat waves occur on a nearly annual basis, affecting hundreds of millions of people. Floods, storm surges and rising seas have made many coastal areas nearly uninhabitable, while droughts and forest fires have had similar effects in other areas. All of this necessitates a global shift from climate change mitigation to emergency adaptation.

CONTEXT

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Current international agreements and mitigation strategies are predicated on the assumption that irreversible tipping points will not be crossed. When the Intergovernmental Panel on Climate Change (IPCC), initially introduced the concept of “large-scale discontinuities” two decades ago, it thought they were only likely to occur at over 5 degrees of warming. Recent research suggests some tipping points could be crossed at far lower temperatures.

While the implications of crossing tipping points are not fully understood, it should be avoided at all costs. The collapse of the Amazon ecosystem and other carbon stores, such as permafrost and boreal forests might create localised vulnerabilities with global spill over effects. The disabling of the Atlantic Meridional Overturning Circulation could destabilize weather systems around the world, including changes in hurricane activity, extreme cold temperatures in places like the United Kingdom and Northern Europe, southward shifts in tropical rainfall and Antarctic ice sheet disintegration. Many around the world are vulnerable. As much as 40 percent of the world’s population lives in hot tropical regions that would be exposed to life-threatening heat, and around 600 million people currently live in coastal zones which are vulnerable to flooding.

IPCC 6 TIPPING POINTS RISK ASSESMENT

Adapted from: IPCC AR6 WG2 Fig. SPM.3 a & b

This series is part of the Strategic Foresight for Successful Net-Zero Transitions toolkit which assists governments and organisations to develop forward-looking, adaptive and future-ready strategies for net-zero emission transitions.

Each part of the series showcases one “Possible Disruption” during the 2030-2050 period that could generate new opportunities or challenges for public policy. Each disruption was developed with foresight, academic and policy experts and represents a plausible extreme in a rapidly changing and uncertain future.

SIGNAL

SIGNAL

The Conger ice shelf in Antarctica collapsed following temperatures 40C above seasonal averages.

Research suggests it may already be too late to prevent tipping points.

SIGNAL The Amazon rainforest, an important carbon sink, has become a net carbon emitter.

POTENTIAL IMPLICATIONS Large-scale devastation due to sea level rise, extreme heat and other hazards may necessitate a redirection of public funds towards adaptation measures. Disruptions to food systems and ecosystem services could lead to a loss in economic productivity and employment, having a disproportionate impact on the poor, the very young, the elderly and those with disabilities.

Countries may face the collapse of staple crops and widespread hunger. Many global value chains could collapse and financial markets destabilized as long-term investments become less desirable.

Certain areas could become uninhabitable leading to mass abandonment and unprecedented migration. In many countries, infrastructure may not have been designed for repeated extreme weather events and could require expensive retrofits and updates. Cities may need to suddenly accommodate an influx of migrants and larger populations. Tensions could arise between climate migrants and domestic populations.

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Constant, localized crises may affect global solidarity and collaboration on climate change mitigation and adaptation. Widespread desperation could lead citizens to demand drastic state actions without concern for long-term consequences. Governments may begin to use emergency measures frequently, eroding democratic norms at a time when faith in institutions is likely to plummet already due to their failure to protect citizens from climate disasters. Frequent mass casualty weather events could create an incentive for geoengineering interventions without widely agreed upon precautions in-place.

QUESTIONS FOR POLICYMAKERS

POLICY RESPONSES

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What can be done to ensure alignment between strategies for climate change mitigation and adaptation?

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What proactive investments in adaptation are immediately needed to prepare for the likelihood of multiple environmental crises occurring simultaneously?

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What can be done to develop the least risky last resort actions (e.g. geoengineering or drastic carbon austerity measures) and establish shared standards for collaborative implementation?

In 2017, the Quinault Indian Nation in the Pacific Northwest of the United States developed the Taholah Village Relocation Master Plan. Based on projected hazards from both climate change and the Cascadia Subduction Zone, the town faces tsunamis, riverine flooding, and coastal storm surges. The plan moves over 300 housing units, administrative buildings, a school, and cultural centers uphill out of flood zones by 2030. To date, the tribe has built 150 homes and an new administrative complex using a combination of federal funding and their own budget.

STRATEGIC FORESIGHT FOR SUCCESSFUL NET-ZERO TRANSITIONS www.oecd.org/strategic-foresight | foresight@oecd.org