Two Harvests Are Better than One: Double Cropping as a Strategy for Climate Change Adaptation
研究了双季种植作为气候变化适应策略的可行性，通过分析日本水稻和小麦的生产数据，发现气候变暖可使适宜双季种植的面积增加近三倍，从而抵消气候变化带来的产量和利润损失。
Abstract Adaptation of agriculture to climate change is essential for reducing its negative impacts. This article evaluates the feasibility of double cropping, which has received relatively little consideration yet holds potential as an adaptation strategy. To assess its feasibility, growing seasons and economic profitability as calculated from crop yield and quality are considered. Accordingly, methods are developed for quantifying the determinants of crop yield and quality grade in a simultaneous equation system that directly expresses the ordered and fractional nature of grade shares. An empirical application to rice and wheat production in Japan reveals that, without any adaptation strategy, climate change will decrease revenues of both crops due to the reduction in yield and quality. Adjusting planting dates helps to avoid such negative impacts for rice but not enough for wheat in southern Japan. However, climate change provides an opportunity for another adaptation strategy—double cropping. Warmer climates enable many regions to shift from a single cropping system to a rice‐wheat double cropping system by shortening the length of the wheat growing season and by delaying the optimal timing of rice planting. As a consequence, the area suitable for double cropping is nearly tripled, suggesting a strong potential to offset climate‐induced production and profit losses.