Spatiotemporal dynamic of rice production and its carbon footprint in Hainan, China: Implications for food security and environmental sustainability

Rice (Oryza sativa L.) feeds more than half of the global population and faces the critical issues related to food security and environmental sustainability. This study analyzed double rice production data from 2010 to 2020 to assess its spatiotemporal dynamic in food production and carbon (C) footprint in Hainan province, China. The results revealed a 29.5% reduction in rice planting area, leading to a significantly decreased rice self-sufficiency rate from 38% to 33% from 2010 to 2020. During this period, the carbon footprint per unit area (CFa) for early, late, and double rice showed a fluctuating upward trend ranging from 8.1 to 8.4, 8.9 to 9.2, and 17.0 to 17.4 t CO₂-eq ha⁻¹, respectively. The total greenhouse gas (GHG) emissions of rice production decreased to around 2 million t CO₂-eq, primarily due to reduced planting area. The C sequestration initially increased before decreasing to 1.2 million t C in 2020 at a temporal scale. Spatially, the northeast and southwest regions exhibited ∼70% of the total GHG emissions and ∼80% of C sequestration. The regional C footprint per unit yield displayed less favorable outcomes, with some areas (e.g., Wenchang and Haikou) experiencing emission hotspots in recent years. Higher yield and smaller CFa for Lingao and Tunchang were observed compared to the average between 2010 and 2020. This study provides insights into the spatiotemporal dynamics of double rice production and GHG emissions in Hainan, offering a scientific reference for regional food security and environmental sustainability.