selecting a single global climate simulation dataset from a plurality of candidate simulation datasets, wherein each candidate simulation dataset consists of outputs from a global climate simulation model (GCM);

training the NN-based climate forecasting model on the selected global climate simulation dataset, wherein the NN-based climate forecasting model comprises a predictive neural network which produces a forecast outputs without needing to execute the GCM corresponding to the selected global climate simulation dataset, wherein for a given input into the NN-based climate forecasting model, a forecast output at the target lead time is generated by the NN-based climate forecasting model based on the given input, wherein the forecast output at the target lead time is compared to a corresponding desired output at the target lead time, and wherein the given input and the corresponding desired output at the target lead time are elements of a time series within the selected global climate simulation dataset; and

validating the NN-based climate forecasting model on a set of observational historical climate data.