A new impacts-driven approach to understanding climate vulnerabilities

English Abstract:

Extreme weather events have the biggest impact on society, yet are often the climate phenomena we understand least, especially in GCMs. Even though these understandings are limited, there are opportunities from a hydrologic perspective to use past weather events to better quantify conditions (e.g. extent, duration, and intensity of precipitation, snow pack, soil moisture) that caused those events. This will help identify how the character of simulated future events, as they continue to evolve, differs from those of the past. To explore this, this research works to develop an impacts-driven method that uses the same modeling framework as past climate change studies (global climate models, hydrological models, and impact assessment tools), but reverses the typical direction of information flow: first, resource managers identify a metric of concern, e.g., flow above X cfs at a certain gauge, then hydrologic factors that lead to the metric are diagnosed, and finally connections to climate drivers are quantified. This presentation will discuss the opportunities and challenges of this new approach in the Pacific Northwest region of North America. Floods in the Skagit River in western Washington, selected after numerous meetings with stakeholders throughout the region, will be highlighted as a test case for this impacts-driven approach.