Joint Hazard Assessment for Urban Decision-Makers in the Northeastern United States

Abstract:

Most of the large municipalities of the Northeastern U.S. have conducted adaptation assessments that include downscaled climate projections. In these assessments, each climate variable has generally been considered independently, and downscaling methodologies have generally not been tailored to the extremes of a variable’s distribution. In the wake of events such as Hurricane Sandy, stakeholder need and scientific advances are increasingly converging towards assessments focused on extreme events from a joint hazards perspective, across multiple climate variables. Such a joint approach requires consideration of possible correlation across climate variables (e.g., changes in relative sea level rise and coastal storms), as well as emphasis on additional variables—and their extremes—not considered quantitatively to date (e.g., humidity). This presentation will focus on two examples: 1) heat stress, based on combined impacts of high temperatures and high humidity, and 2) coastal flood risk associated with combined impacts of sea level rise and changes in coastal storms. This talk will demonstrate how the joint hazards approach can lead to large changes in projected extreme event frequency, relative to downscaling approaches that treat climate variables as independent. Challenges—and opportunities--associated with downscaling across multiple climate variables, with an emphasis on the extremes of the variables, will also be highlighted.