Constraining Decadal Variability Yields Skillful Projections of Near-Term Climate Change

Targeted adaptation to near-term climate change requires accurate, reliable, and actionable climate information for the next few decades. Climate projections simulate the response to radiative forcing, but are subject to substantial uncertainties due to internal variability. Decadal climate predictions aim to reduce this uncertainty by initializing the simulations using observations, but are typically limited to the next 10 years. Here, we use decadal predictions to constrain climate projections beyond the next decade and demonstrate that accounting for climate variability improves regional projections of 20-year average temperatures. Applying this constraint to climate projections of the near future until 2035, summer temperatures over land regions in Asia and Africa tend to show stronger changes within the warming range simulated by the larger, unconstrained, ensemble-consistent with a warm phase in North Atlantic variability. This improved regional climate information can enable tailored adaptation to climate changes in the coming decades.

Automated summary

This study uses decadal climate predictions to improve regional projections beyond the next decade, demonstrating that considering climate variability can enhance the accuracy of 20-year average temperature predictions. Specifically, summer temperatures over land regions in Asia and Africa are expected to show stronger changes within the warming range, consistent with a warm phase in North Atlantic variability. This improved regional climate information can facilitate tailored adaptation to climate changes in the coming decades.