CMIP6 models simulate heavier future rainfall over the Highlands than across other agricultural areas of Yemen

Abstract

The climate of Yemen remains largely unstudied, leading to major uncertainties and a lack of understanding of future extreme rainfall events and how they are likely to affect agriculture. Here, we examine future heavy rainfall events for the period 2025–2100 using the latest state-of-the-art Coupled Model Intercomparison Project Phase 6 (CMIP 6). Based on differences in rainfall regimes, we divided the study area into two distinct parts: Highlands and the Red Sea Coast & Tihama Plain region. Analyzing annual total precipitation when daily precipitation exceeds the 95th percentile of wet day precipitation (R95p), we found that models predict 16–25% heavier future rainfall over the Highlands than across the Tihama Plain and other agricultural parts of Yemen. By mid-century, the Highlands will experience ~ 25% heavier rainfall than other agricultural areas under SSP2-4.5 and ~ 16% heavier under SSP5-8.5. In both cases, the risk of rejecting the null hypothesis (H0) when it is true is lower than 5%. These results suggest that whether the current status quo of emissions continues, or the radiative forcing level is stabilized at 4.5 W/m2, heavy rainfall events are projected to increase more over the Highlands than over other agricultural areas of Yemen. Considering the projected increase in heavy rainfall events, we argue that Yemen desperately needs investments and innovations that will foster readiness and overall climate disaster preparedness. Efforts and investments will need to be directed more toward bridging the gap between producers of climate information and end users. Ultimately, these efforts will contribute to shaping the future of farmer decision support across Yemen.