New Methods Needed to Assess Ecosystem Productivity Response to Precipitation Variability

Abstract Dai et al. (2025, https://doi.org/10.1029/2024GL113861 ) address a critical question: how ecosystem primary productivity will respond to changes in precipitation variability. To do so, the authors use the asymmetry index (AI), a metric commonly used to quantify the asymmetry in productivity response to wet and dry precipitation anomalies. Productivity asymmetry is a data‐driven, model‐independent metric to understand how ecosystem productivity responds to precipitation change. However, AI does not by itself reflect asymmetry in productivity response and must be used cautiously to infer how productivity will respond to changes in precipitation variability. This comment criticizes the use of AI alone and suggests alternative lines of evidence to provide appropriate context to interpret AI. Finally, we summarize the open research questions needed to be addressed to bracket how productivity has changed and will respond under future climates.