Global rice land suitability and adaptation strategies under climate change

Rice is a vital dietary staple for over half the global population, especially in Asia, Africa, and Latin America, underpinning food security. Rising temperatures and shifting precipitation patterns due to climate change threaten rice production, necessitating adaptive measures to sustain agricultural systems. This study evaluates rice land suitability across 19 sub-regions under current and future climate scenarios, assessing sowing adjustments to counter these impacts. The analysis utilized high-resolution climate data from WorldClim, encompassing historical (2001-2021) and future (2041-2060) projections based on CMIP6 models under medium-emission (SSP245) and high-emission (SSP585) scenarios. Soil data were obtained from the FAO Harmonized World Soil Database, with rice areas mapped using SPAM2020. Liebig's Law of the Minimum identified limiting factors during a standardized growing season, defined by regional sowing and harvest dates. Early sowing (ES) and late sowing (LS) adaptations were modeled to optimize climatic alignment, with suitability categorized into weakly, marginally, suitable and very suitable. Climate change significantly alters rice land suitability across 19 sub-regions, with tropical areas like South-Eastern Asia, Southern Asia, and Eastern Africa experiencing declines in suitable land for both irrigated and rainfed systems due to heat stress and irregular rainfall. In contrast, temperate regions such as Eastern Asia, South America, and Eastern Europe see gains in suitable land, driven by extended growing seasons. Marginal land challenges emerge in Southern and South-Eastern Asia. Late sowing proves the most effective adaptation strategy in major rice-producing regions like Eastern Asia, South-Eastern Asia, and Southern Asia, enhancing land suitability for irrigated systems by aligning with cooler periods and improving rainfed suitability in monsoon-dependent zones.This study highlights the varied impact of climate change on rice land suitability, with tropical regions facing greater losses and temperate zones gaining potential. Late sowing emerges as a key adaptation in Eastern and South-Eastern Asia, offering a sustainable approach to maintain rice production. These findings advocate for region-specific policies promoting timely sowing adjustments and resilient practices to ensure global food security amid escalating climate challenges.