气候变化对全球玉米贸易网络影响分析

THE IMPACT OF CLIMATE CHANGE ON THE GLOBAL MAIZE TRADE NETWORK

关键词:  气候变化  全球玉米贸易网络  网络核心度  粮食安全  农业贸易治理

Key words:  climate change  global maize trade network  network coreness  food security  agricultural trade governance

摘要:

目的 系统评估气候变化对全球玉米贸易网络的影响，可为制定提高气候变化应对韧性的全球玉米供应链优化策略提供参考。方法 文章基于1990—2021年50个样本国家的面板数据，利用面板数据固定效应模型，从出口的角度实证分析了以降雨量和温度表示的气候变化对以核心度测度的全球玉米贸易网络的影响，并进行了稳健性检验、异质性检验和中介效应检验。结果 （1）降雨量和温度对样本国家玉米贸易网络核心度都具有显著的正向影响，且降雨量的影响程度小于温度。（2）气候变化对样本国家玉米贸易网络核心度的影响存在明显的气候变化程度、收入水平和地理位置异质性。降雨量和温度对低温度样本国家玉米贸易网络核心度有显著正向影响，对中降雨量和低降雨量样本国家玉米贸易网络核心度也有显著正向影响；低收入样本国家应对气候变化影响玉米贸易网络核心度的能力弱于高收入样本国家；降雨量和温度对欧洲样本国家玉米贸易网络核心度有显著正向影响，温度对非洲样本国家玉米贸易网络核心度有显著负向影响。（3）玉米产量在气候变化影响样本国家玉米贸易网络核心度中具有显著的中介效应。结论 应提高气候变化应对韧性、完善全球农业贸易治理和加大产业政策支持力度，促进全球玉米贸易网络平稳运行，提高中国统筹利用国内外玉米市场能力。

Abstract:

Systematically assessment of the impact of climate change on the global maize trade network, can help provide scientific basis for formulating global maize supply chain optimization strategies to improve climate change resilience. Based on the panel data of 50 sample countries from 1990 to 2021, this research empirically analyzed the impact of climate change expressed by rainfall and temperature on the global maize trade network measured by the coreness from the perspective of export by using the panel data fixed-effect model, and then conducted robustness tests, heterogeneity tests and mediating effect tests. The results were showed as follows. (1) Both of rainfall and temperature had a significant positive impact on the coreness of maize trade network in the sample countries, and the influence of rainfall was less than that of temperature. (2) There were obvious heterogeneities in the degree of climate change, income level and geographical location of the impact of climate change on the coreness of maize trade network in the sample countries. Both of rainfall and temperature had a significant positive impact on the coreness of maize trade network in the low-temperature sample countries, and also had a significant positive impact on the coreness of maize trade network in the medium-rainfall and low-rainfall sample countries. The ability of low-income countries to cope with the impact of climate change on the coreness of maize trade network was weaker than that of high-income countries. Both of rainfall and temperature had a significant positive impact on the coreness of maize trade network in the European sample countries, while temperature had a significant negative impact on the coreness of maize trade network in the African sample countries. (3) Maize production had a significant mediating effect on the coreness of maize trade network in the sample countries affected by climate change. Therefore, this research recommends that great efforts should be made to enhance resilience in response to climate change, improve global agricultural trade governance, and increase industrial policy support to promote the smooth operation of global corn trade network and improve China's ability to make overall use of domestic and foreign corn markets.