中国七大地区“气候变化—作物产量—经济影响”综合评价

Comprehensive assessment of “climate change-crop yield-economic impact” in seven sub-regions of China

农业作为响应气候变化最敏感的领域之一,未来作物产量可能受到深刻影响。量化气候变化冲击作物产量导致的最终经济影响,需要综合"气候变化—作物产量—经济影响"开展链式研究。文中采用系统回顾和Meta回归分析方法整合了55篇文献的667项研究结果,推导出我国七大地区主要作物(水稻、玉米、小麦)产量与地区内未来温度和降水变化的定量关系,并将其作为农业部门的损失量代入改进的多区域投入产出模型,量化七大地区内与地区间遭受的经济波及影响(ERE)。结果显示:(1)气候变化对我国作物产量的影响主要体现在温度升高上,每升温1℃减产2.6%~12.7%,东北和西北地区作物受升温影响最显著;(2)气候变化导致的作物减产将对经济产生更严重的波及影响,GDP因作物减产每下降1%将额外产生17.8%的波及影响;(3)21世纪末,若不考虑CO2肥效作用,作物减产导致的ERE将占GDP的-0.1%~13.6%(负值表示收益),最悲观情况下ERE与当前我国农业总产值相当(2012年为基准年);(4)不同地区受ERE影响程度的差异较大,因各区之间产业结构、贸易联系及经济发展程度存在差异,西南地区遭受本区及来自其他地区的ERE比华东地区高2.8~8.5倍。

Agriculture is one of the most sensitive areas in response to climate change, and future crop yields may be profoundly affected. To quantitatively assess the final economic impact of climate change on crop yields, it is necessary to conduct a chain study on the comprehensive “climate change-crop yield-economic impact”. In this study systematic assessment and Meta regression methods were used to integrate 667 research results from 55 literatures, deriving the quantitative relationship between the main crop yields(rice, corn, wheat) in the seven subregions of China and future temperature and precipitation changes in the local area. Subsequently, the crop yields data were input to the improved multi-regional input-output model as the loss of the agricultural sector to evaluate the economic ripple effects(ERE) in and between the seven sub-regions. Results are as follows.(1) The impact of climate change on crop yields was mainly reflected in temperature increases, with an average yield loss of 2.6%-12.7% per℃, and with crop yields being more vulnerable in Northeast China and Northwest China than in other sub-regions.(2) Crop failure caused by climate change is estimated to have a more serious impact on China’s economy, each 1% drop in GDP due to crop failure will have an additional 17.8% ripple effects.(3) At the end of the 21 st century, the ERE is -0.1%-13.6% of GDP(negative values indicate economic gains) without considering CO2 fertilization effect, of which the ERE in the most pessimistic pathway is equivalent to the total agricultural output in China in 2012.(4) Sub-regional-level results show an uneven distribution of economic impact in China, which is related to the regional economic development. Southwest China experiences 2.8-8.5 times more ERE than East China.