Attribution of Extreme Weather and Climate Events and their Impacts Report

Decades of data and research indicate that human-caused climate change is altering the frequency and intensity of several types of extreme events, such as heat waves and extreme rainfall events. Even as those trends become clearer, extreme event attribution (EEA) seeks to assess the degree to which climate change contributed to any specific event. EEA studies provide information that can be useful for public understanding, planning and risk management, policy and legal contexts, and scientific research. This report evaluates the state of EEA science, updating a National Academies report published in 2016. The report also assesses the emerging field of extreme event impact attribution (EEIA).

The number of EEA studies has grown substantially over the past decade as scientific tools, observational datasets, and methodologies have advanced, enabling attribution studies to be completed within days of an event. However, challenges remain, including limited model capabilities for small-scale regional events, representation of key atmospheric processes, and attribution of compounding, cascading, and record-breaking events. The report examines these advances and remaining challenges and provides recommendations for strengthening attribution science, improving collaboration with local experts and stakeholders, and advancing research, data, and modeling capabilities worldwide.