Rice Faces Thermal Limit With Rapid Warming

Why this is here: Rice photosynthesis begins to shut down at around 104°F (40°C), a temperature that increasingly threatens yields in major growing regions.

Nicolas Gauthier at the Florida Museum of Natural History and colleagues determined climate change now exceeds the pace of rice evolution. The researchers analyzed nearly a millennium of climate data alongside archaeological evidence of rice farming. They found rice cultivation has remained largely limited to areas with mean annual temperatures below 82.4°F (28°C) over 9,000 years.

Current warming trends are occurring roughly 5,000 times faster than the rate at which rice has historically evolved, potentially reaching a thermal limit for the crop. While breeding heat-resistant strains or shifting cultivation to new regions is possible, moving paddies built over centuries presents practical difficulties.

About 90% of global rice cultivation happens in Asia, supporting over half the world’s population, and disruptions could significantly impact food security. The team acknowledges human adaptation is possible, but its limits are becoming increasingly apparent as warming continues.