Extreme Hurricane Rainfall affecting the Caribbean mitigated by the Paris Agreement Goals

Hurricanes are among the most impactful extreme weather events affecting small island states such as the Caribbean and require long-term planning for community and infrastructure resilience. By coupling an offline dynamical hurricane model to the output of a large ensemble of global climate model simulations from the Half a degree of Additional warming Prognosis and Projected Impacts (HAPPI) project, we assess how the impacts of hurricanes may change under the Paris Climate goals. Specifically, we concentrate on hurricane rainfallover particular regions, with both the mobility and intensity of a hurricane being key drivers of local level impacts. For example, Hurricane Dorian (2019) caused widespread devastation when it stalled over The Bahamas as a category 5 storm. We show that since 1970 only one other hurricane stalled at this strength: Hurricane Mitch (1998). Due to a combination of increased stalling and precipitation yield under a warmer world, our analysis indicates a greater likelihood of extreme hurricane rainfall occurring in the Caribbean under both Paris Agreement scenarios of 1.5◦C and 2◦C Global Warming goals, compared to present climate projections. Focusing on specific hurricane events, we show that a rainfall event equal in magnitude to Hurricane Maria is around half as likely to occur under the 1.5◦C Paris Agreement goal compared to a 2◦C warmer climate. Our results highlight the need for more research into hurricanes in the Caribbean, an area which has traditionally received far less attention than mainland USA and requires more comprehensive infrastructure planning.