暨南大学硕士生 仲政 合作论文在Journal of Development Economics发表

Climate change is expected to reduce crop yields, but knowledge on how it affects agricultural land use is still limited. This paper empirically investigates the induced cropland adjustments in responding to long-run climate change in China. Based on county-level data over several decades, we employ a moving-average specification that exploits within-county variation in local climate normals. We show that cropland expands with rising temperature (precipitation) in cold (dry) areas, while the effect is reversed in hot (humid) areas. The results are consistent with the “long-difference” estimates and robust to a host of different specifications. Besides, local crop mix also evolves with the changing climate. However, accounting for the crop-mix adjustments, climate change by the mid-century is still predicted to significantly lower the national calorie provision through induced cropland adjustments, and an average yield growth of 17.6% (21.2%) would be required to offset the associated loss under RCP 4.5 (RCP 8.5).

   气候变化预计会降低作物产量，但对其如何影响农业土地利用的了解仍然有限。本文实证研究了中国应对长期气候变化的耕地调整。基于几十年来的县级数据，我们采用了移动平均方法，该方法利用了当地气候正常值的县内变化。我们发现，在寒冷（干燥）地区，农田会随着温度（降水量）的升高而扩张，而在炎热（潮湿）地区，这种影响会逆转。结果与“长差”估计一致，并对许多不同的方法具有稳健性。此外，当地的作物组合也随着气候变化而变化。然而，考虑到作物结构的调整，预计到本世纪中叶，气候变化仍将通过诱导的农田调整大幅降低国家热量供应，需要17.6%（21.2%）的平均产量增长来抵消RCP 4.5（RCP 8.5）下的相关损失。