Existential climate-related security risk: A scenario approach

Analysis of climate-related security threats depends significantly on understanding the strengths and limitations of climate science projections. Much scientific knowledge produced for climate policy-making is conservative and reticent. Climate change now represents a near- to mid-term existential threat to human civilisation. But this is not inevitable. A new approach to climate-related security risk-management is thus required, giving particular attention to the high-end and difficult-to-quantify “fat-tail” possibilities, in order to avoid such an outcome. This may be most effectively explored by scenario analysis.

In this report, a 2050 scenario of the high-end risks is outlined in which accelerating climate change impacts pose large negative consequences to humanity which might not be undone for centuries. To reduce or avoid such risks and to sustain human civilisation, it is essential to build a zero-emissions industrial system very quickly. This requires the global mobilisation of resources on an emergency basis, akin to a wartime level of response.