Climate change represents a threat to future food security. There has been plenty of recent research on the effects of climate change on agricultural yields, productivity, and cropping decisions. In the agricultural trade domain, researchers have shown that trade can serve as a climate adaptation device, buffering the effects of shocks in importing regions where domestic agricultural systems are negatively affected by adverse weather shocks and climate change. But how will climate change affect the trade flows of exporting countries?
This question is the focus of our recent working paper with co-authors Kjersti Nes and Dan Scheitrum. We assess the impacts of growing-season extreme weather events on agricultural trade outcomes in the short run, as well as the trade implications of long-run shifts in climate expectations and variability. Our analysis focuses on trade in three crops—corn, rice, and soybeans. Together, these crops account for approximately $12.4 billion in U.S. exports and about 50% of calorie consumption worldwide.
What did we find?
We find that—in the short-run—extreme weather events can be extremely disruptive to agricultural trade. A growing-season weather shock with about a 1-in-100-year odds reduces corn and rice exports by more than 60%. Figure 1 shows the average annual losses in U.S. corn and rice exports associated with weather variability, evaluated as a percentage of potential exports. (Note that soybean trade appears to be less sensitive to extreme weather events.) As shown in Figure 1, on average, the U.S. loses approximately 4% of potential corn exports and 8.5% of potential rice exports due to weather variability. A 10% increase in weather variability would increase these average losses to 6.5% for corn and 10.8% for rice.
In the long run, we find that climate change may have large impacts on U.S. grain exports, as production shifts to regions with more temperate climates, like Canada or Argentina. Figure 2 shows our estimates of the long-run impacts of climate change on U.S. grain exports under +2°C and +4°C climate change scenarios. Under a +2°C climate change scenario, U.S. corn exports are projected to fall by as much as 44%. Things may be even more bleak if warming temperatures are accompanied by an increase in climate variability. When we simulate the +2°C climate change scenario with a 15% increase in climate variance, U.S. corn exports are projected to fall by 50%. U.S. rice and soybean exports may be hit even harder than corn.
Figure 1: Short-Run Impacts of Weather Variability on U.S. Agricultural Exports
Figure 2: Long-Run Impacts of Climate Change on U.S. Agricultural Exports
Gammans, Matthew, and K. Aleks Schaefer. “What might climate change mean for U.S. grain exports?” Southern Ag Today 3(12.4). March 23, 2023. Permalink
Photo by Guillaume Falco: https://www.pexels.com/photo/icebergs-2229887/