The Third Degree Popular

Since the 2015 Paris Agreement, most global climate focus has centred on limiting warming to 1.5–2°C. Yet political inaction and inadequate commitments mean the world is likely on track for 3°C or more of warming — a trajectory with far more catastrophic implications. This paper expands on a previously published scenario exploring the security risks of 3°C warming, outlining potential consequences such as mass displacement, uninhabitable regions, and the breaching of climate tipping points consistent with a “Hothouse Earth.” These scenarios are not predictions, but tools for strategic insight, helping decision-makers “think the unthinkable” and prepare for destabilising change.

The paper also revisits a 2007 US national security scenario that anticipated many of today’s unfolding crises, reinforcing the urgent need for serious climate contingency planning. In Australia, a culture of denial and delay by political and corporate elites has left the population dangerously unprepared. Climate change is now the greatest threat to national security and economic stability. Immediate and holistic scenario planning is essential to avoid irreversible outcomes. Leadership must urgently shift to protect the future — not cling to a failing past — and the conversation must be mainstreamed to build public support for sweeping change.