Projected risk and vulnerability to heat waves for Montreal, Quebec, using Gaussian processes

Urban areas face increasing climate risks and are at the forefront of adaptation challenges. Despite the growing number of cities that are developing adaptation plans, they often fail to implement, monitor, and evaluate them. This article addresses this issue by modelling a comprehensive risk assessment that includes vulnerability using Gaussian processes. Mortality during heat waves for the City of Montreal, Quebec, is used as a case study. The vulnerability model includes sensitivity components (age and socioeconomic variables) and an adaptive capacity component (a suitable level of vegetation to decrease the urban heat island effect). Various aging and climate scenarios (SSP1-2.6, SSP2-4.5 and SSP5-8.5) are used for projections up to year 2100. SHAP values are used to show features contributions to the model. As the climate warms, Montreal will face increasing summer mortality. The city should therefore increase its vegetation cover in vulnerable neighbourhoods. Despite inherent limitations to the complexity of risk modelling, this approach facilitates the implementation of adaptation solutions and their monitoring. Greater effort should be made in the future to improve comprehensive risk modelling and more research is required to validate which framework is best in closing the gap between science and political decisions.