Double benefit of limiting global warming for tropical cyclone exposure

摘要

Tropical cyclone (TC) impacts are expected to worsen under continued global warming and socio-economic development. Here we combine TC simulations with an impact model to quantify country-level population exposure to TC winds for different magnitudes of global mean surface temperature increase and future population distributions. We estimate an annual global TC exposure increase of 26% (33 million people) for a 1 degrees C increase in global mean surface temperature, assuming present-day population. The timing of warming matters when additionally accounting for population change, with global population projected to peak around mid-century and decline thereafter. A middle-of-the-road socio-economic scenario combined with 2 degrees C of warming around 2050 increases exposure by 41% (52 million). A stronger mitigation scenario reaching 2 degrees C around 2100 limits this increase to 20% (25 million). Rapid climate action therefore avoids interference with peak global population timing and limits climate-change-driven exposure. Cumulatively, over 1.8 billion people could be saved by 2100. Tropical cyclone winds intensify with warming but the impacts depend on global population, which is likely to peak by mid-century and then decline. Impact modelling suggests that stronger mitigation, under which warming would peak after the population begins to decline, may spare 1.8 billion people from impacts by 2100.