Artificial intelligence and downscaling global climate model future projections
Rasmus E. Benestad
TL;DR
Problem: AI/ML methods for downscaling GCM future projections risk non-stationarity and non-representative training data. Approach: the author reviews historical AI/ML efforts, defines downscaling vs interpolation/bias-adjustment, and contrasts with empirical-statistical downscaling (ESD), stressing proper benchmarking and transferability. Findings: AI/ML can emulate RCMs and extract meaningful features, but performance is strongest when trained on future-period simulations and evaluated across GCMs; ESD often offers greater robustness and efficiency. Significance: the paper argues for rigorous, physics-informed, and performance-based evaluation to avoid hype and to determine the practical value of AI/ML in climate downscaling.
Abstract
A critical review of artificial intelligence and deep machine learning (AI/ML) applied to downscaling of global climate model simulations provides some words of caution, based on past experiences and well-established principles. Recent papers tend to ignore more subtle successes with statistics and mathematical based downscaling, and there are examples of inappropriate evaluation strategies and incomplete accounts of the scientific progress when it comes to climate downscaling. An incomplete description state-of-the-art and a dogmatic approach to evaluation may give a deceiving impression that AI/ML is superior to more statistics and mathematics based methods.
