Deep uncertainty in long-term hurricane risk: scenario generation and implications for future climate experiments

Produced as part of the The Munich Re programme: evaluating the economics of climate risks and opportunities in the insurance sector CCCEP research programme theme

Also known as Munich Re Technical Paper: 8


Current projections of long-term trends in Atlantic hurricane activity due to climate change are deeply uncertain, both in magnitude and sign. This creates challenges for adaptation planning in exposed coastal communities.

We present a framework to support the interpretation of current long-term tropical cyclone projections, which accommodates the nature of the uncertainty, and aims to facilitate robust decision making using the information that is available today.

The framework is populated with projections taken from the recent literature to develop a set of scenarios of long-term hurricane hazard.

Hazard scenarios are then used to generate risk scenarios for Florida using a coupled climate-catastrophe modelling approach.

The scenarios represent a broad range of plausible futures; from wind-related hurricane losses in Florida halving by the end of the century, to more than a four-fold increase due to climate change alone.

We suggest that it is not possible, based on current evidence, to meaningfully quantify the relative confidence of each scenario.

The analyses also suggest that natural variability is likely to be the dominant driver of the level and volatility of wind-related risk over the coming decade; however, under the highest scenario, the superposition of this natural variability and anthropogenic climate change could mean notably increased levels of risk within the decade.

Finally, we present a series of analyses to better understand the relative adequacy of the different models that underpin the scenarios and draw conclusions for the design of future climate science and modelling experiments to be most informative for adaptation.

Nicola Ranger and Falk Niehörster