Decadal prediction: Can it be skillful?

Decadal prediction, a new field of study, focuses on time evolving regional climate conditions over the next 10-30 years, which is a time period of interest to infrastructure planners, water resources managers, and others. The decadal time scale offers an important bridge for informing adaptation strategies as climate varies and changes. Because decadal prediction lies between seasonal/interannual forecasting and longer-term climate change projections, there is some knowledge from El Nino forecasting that can be applied to decadal prediction, and climate change commitment and forcing changes also provides some information as to how skillful decadal predictions might be. Because an accurate observed initial climate state is thought to be important for decadal prediction skill, it is important to maintain a comprehensive global climate observing system, with emphasis on the ocean. The use of observations to evaluate model biases, the effect of model systematic errors on prediction skill, and how to reduce those biases, are major challenges for decadal prediction.