Increased coastal development is the primary cause of the recent dramatic increases in the damage faced by society and insurers. Natural fluctuations in tropical cyclone frequency are another factor. The media and various advocacy groups often incorrectly attribute increased damages to global warming, but they are probably not so attributable. Enhancing our understanding of, and ability to predict, natural variability in tropical cyclone activity on time scales of years to decades will benefit society and business. Any approach to forecasting tropical cyclone variability must include a rigorous understanding of the uncertainties in a way that is relevant to the science community, insurers, governments, and other groups in society.
Insurers are most interested in tropical cyclones that impact land.
On time scales of years to decades, recurrence is probabilistic, and the probability of the next event is independent of the timing of the last occurrence. Better estimates of the frequency of landfalling tropical cyclones can immediately be incorporated into existing insurance approaches to risk assessment and management. The quality of existing historical records of tropical cyclone activity generally decreases back in time. Reliable records of tropical cyclone activity throughout the Atlantic commence with the advent of aircraft reconnaissance flights in the 1940s. Reliable records of US landfalling tropical cyclones extend back to around 1900.