Economic shifts in agricultural production and global trade from climate change. Report for the International Technical Conference on Climate Change, Agricultural Trade and Food Security

[摘要] In addition to expanding agricultural land area and intensifying crop yields, increasing the global trade of agricultural products is one mechanism that humanity has adopted to meet the nutritional demands of a growing world population. Our objective is to explore the consequences of climate change for the world’s agricultural trade network. To do this, we coupled seven Global Gridded Crop Models from the Agricultural Model Intercomparison and Improvement Project (AgMIP) database, which projects crop yields based on five Earth System Models, to a global economic model developed at CSIRO to project the economy to 2100. Agricultural productivities in the economic model are exogenously forced based on the AgMIP database. Here we present a novel approach to quantify the structural changes in the agricultural trade network under two contrasting global greenhouse gas emissions and climate change scenarios, based on two Representative Concentration Pathways (RCP), RCP4.5 that limits global temperature reaching 1.5˚ C, and RCP8.5 scenario that results in an increase in global temperatures above 2˚ C by 2050. We use a modified version of the Shannon entropy index, widely used in ecology to characterise species diversity, to quantify and characterise the structure of the global agricultural trade network. Our results show that the global trade network becomes more centralised under RCP8.5, with a few regions dominating the food markets. Under the carbon mitigation scenario, RCP4.5, in contrast, the trade network is more distributed and more regions are involved as either importers or exporters. Theoretically, the more distributed the structure of the global trade network, the less vulnerable the systems is to climatic or institutional shocks.We also found that the structure of agricultural trade projected to 2050, and later in the century, with and without the carbon mitigation scenarios, is significantly different from the current reality. A compelling result is that the amount of agricultural commodities imported by Sub-Saharan Africa will increase dramatically, this is because the largest increase in human population in the next few decades will occur in this region, with a subsequent increase in the demand for food. However, each RCP scenario presents a significantly different story in terms of who the exporting regions could be, and this is driven by shifts in regional climatic conditions that alter the existing agricultural system.Mitigating CO2 emissions as implied by RCP4.5, has the unintended co-benefit of creating a more stable agricultural trading system. Understanding how climate change affects the production and trade of agricultural commodities is vital for ensuring the most vulnerable regions have access to a secure food supply.

[发布机构] CSIRO

[效力级别] Agricultural Systems Analysis and Modelling [学科分类] 地球科学(综合)