Published in PNAS, 2022
Statistical projections of the socioeconomic impacts of climate change are increasingly used in policy, development, and the private sector to understand and prepare for climate risks. Climate uncertainty is the dominant source of uncertainty in many of these projections. Such studies increasingly account for some sources of climate uncertainty, including differences between climate models and emissions scenarios. However, uncertainty due to internal climate variability is generally ignored. We show that internal variability substantially boosts the uncertainty by 38% on average for near-term mortality, corn yields, and gross domestic product projections in the continental United States. Omitting uncertainty due to internal variability could lead to an underestimation of worst-case impacts and/or a misallocation of resources in climate mitigation and adaptation efforts.
Recommended citation: Schwarzwald, Kevin, and Nathan Lenssen. 2022. “The Importance of Internal Climate Variability in Climate Impact Projections.” Proceedings of the National Academy of Sciences 119 (42): e2208095119. https://doi.org/10.1073/pnas.2208095119. https://doi.org/10.1073/pnas.2208095119