Designing extreme climate change scenarios for anticipatory governance

As climate change policy researchers, we applaud Kemp et al.’s proposal (1) to develop integrated catastrophe assessments of extreme climate change scenarios. Current policy efforts are lagging well behind what is needed to meet internationally agreed goals (2), and many climate scientists fear a “beyond 2°C” world is an increasingly likely future (3). We recently argued for a similar scientific extreme scenarios research agenda to support adaptation policy (4). We differ with Kemp et al. (1), however, regarding four important aspects.

First, Kemp et al. (1) propose that the Intergovernmental Panel on Climate Change (IPCC) should take the lead in preparing assessments. Given the importance of extreme climate change research to policy development at multiple scales, we believe an independent, science-based government entity with no policy authority or agenda, similar to the US Geological Survey, is a better choice. Such an entity will be more attuned to the research that policy-making institutions will need to design and implement adaptative measures. Moreover, the IPCC’s consensus approach to climate change assessments has resulted in conservative reports and continuous revelations of “it’s worse than we thought” (5–7).

Second, Kemp et al. (1) focus primarily on research into how interactions between climate and social systems could produce cascading failures. We suggest that they currently underestimate the potential for social chaos to accelerate such collapses (4). More optimistically, however, we propose that the scientific scenario building also explicitly integrates potential social responses to test the possible effects and efficacy of various adaptation policy choices (4).

Third, Kemp et al. (1) propose that governance responses to the assessments be developed through open deliberative democratic methods to ensure fairness and inclusion. While we agree that those are important considerations, some adaptive policy responses to extreme climate change scenarios could be complex and controversial, requiring some measure of expert-driven decision processes. At the very least, relying exclusively on robust democratic processes could preclude consideration of policies that are deemed unacceptable currently, such as forced relocation or using conservation lands for needed housing, but which may be necessary under extreme climate change. Moreover, coordinating different scales of adaptation will almost certainly require intergovernance tradeoffs that will be next to impossible to negotiate democratically if adaptation slips into an emergency response modality.

Finally, our package of proposals for extreme scenario research and policy design draws on concepts in anticipatory governance literature addressing climate change (4). Anticipatory governance uses plausible future scenarios, including the possibility of extreme climate conditions, to test a broad range of policy responses using multiple decision processes (8–10). For this reason, we emphasize that the research agenda both Kemp et al. (1) and we (4) propose must be broadly interdisciplinary, including political scientists, anthropologists, lawyers, and psychologists as well as climate scientists. Only by including probable human responses—positive and negative—in the projections of an evolving world are extreme climate scenarios likely to illuminate the best policy and governance responses.