The impact of climate information choices on city-scale resilience planning in the U.S.

Abstract:

In many United States (US) cities, there is growing evidence of increasing frequency of rainfall extremes, and climate change will further exacerbate these conditions throughout the 21st century. Local government stakeholders are leading efforts in many cities to develop plans that outline resilience strategies to adapt to a changing climate. In this work, we assessed adaptation plans from 86 large US cities to characterize what type of climate information informs local resilience planning. We found that the sources and methods that each plan uses for characterizing observed and future climate change trends are highly diverse. For rainfall extremes, about 55% of the plans we assessed mention extreme rainfall impacts within the city, with some plans only focusing on historical changes. In addition, the rainfall changes discussed in the plans are taken from external assessments that use a variety of trend detection methods, spatial scales, and filtering criteria to assess data quality. The plans that account for future changes mostly use rainfall projections from statistical downscaling methods. Despite the availability of multiple other datasets that provide downscaled climate projections, resilience discussions within each plan are centered around a single dataset. Through an analysis set in the context of city adaptation plans, we assessed the influence of different methodological choices and climate information on resilience decisions at the city scale. The results show that without a comprehensive analysis that includes a range of existing sources and methods of climate information, resilience decisions and outcomes can be different depending on the set of methodological decisions taken by local stakeholders. Given the continued progress of local adaptation efforts, both climate scientists and resilience practitioners can use these results to develop and use more relevant information to increase local resilience to climate change.