A climate impact attribution of historical rice yields in Sri Lanka using three crop models

Sri Lanka’s rice systems are vulnerable to low-yield events that threaten national food security. This study presents an attribution analysis quantifying the effects of climate change on average rice yields (1981–2019) and on the severe low-yield event of 2017 using three crop models (DSSAT, APSIM, CYGMA) driven by factual and counterfactual climate simulations. Results indicate climate change decreased average yields by −4.99% to −0.20%, although impacts on the 2017 event varied by model. Multi-model ensemble analysis suggests significant negative impacts on the Yala season, while projections remain inconclusive regarding the frequency of 2017-level events under future climate scenarios. Findings highlight uncertainties but underscore the importance of improved attribution for informing climate negotiations and loss-and-damage mechanisms.