Attribution of extreme weather events in the context of climate change

This report examines the current state of science of extreme weather attribution, and identifies ways to move the science forward to improve attribution capabilities. As climate has warmed over recent years, a new pattern of more frequent and more intense weather events has unfolded across the globe. Warming increases the likelihood of extremely hot days and nights, favors increased atmospheric moisture that may result in more frequent heavy rainfall and snowfall, and leads to evaporation that can exacerbate droughts.

The relatively young science of extreme event attribution seeks to tease out the influence of human-cause climate change from other factors, such as natural sources of variability like El Niño, as contributors to individual extreme events. Event attribution can answer questions about how much climate change influenced the probability or intensity of a specific type of weather event. As event attribution capabilities improve, they could help inform choices about assessing and managing risk, and in guiding climate adaptation strategies.