Widespread land surface cooling from paddy rice cultivation revealed by global satellite mapping

Abstract

Paddy rice exacerbates climate warming through greenhouse gas emissions but also cools the land surface by enhancing evapotranspiration. While the former effect has received extensive attention, the biophysical cooling effect remains poorly quantified, partly due to the lack of high-quality global paddy rice data. Here, we address this gap by developing a universal rice mapping framework that integrates the strengths of phenology-based and curve-matching methods to construct the global, long-term rice dataset (GlobalRice500) with daily temporal and 500 m spatial resolution. Our analysis reveals that paddy fields annually reduce daytime land surface temperature by 0.21 (±0.0057)–0.27 (±0.0063) °C during the growing season compared to other croplands, with stronger cooling observed in larger fields and partial spillover to surrounding landscapes. These findings provide robust evidence of the surface cooling effect of paddy rice and call for a comprehensive evaluation of its role in climate regulation.