Agricultural yields in certain “hot spots” within the US will be severely diminished by 2050 as a result of the impact that climate change will have on water availability and irrigation, according to a new study from MIT.
The hot spots in question are, unsurprisingly, mostly within the Southwestern US, where agriculture and ranching are already highly dependent upon unsustainable groundwater extraction rates.
To put a specific figure to that assertion: the study predicts that reduced precipitation levels in the region will result in cotton yields there falling to less than 10% of the crop yield that’s expected under optimal irrigation conditions.
Also, Utah’s maize yields — which are already only around 40% the optimal expected yield — are predicted to fall to around 10% of the optimal expected yield by the middle of the century.
The press release provides more: “In the Northwest, water shortages to the Great Basin region will lead to large reductions in irrigated forage, such as hay, grasses, and other crops grown to feed livestock. In contrast, the researchers predict a decrease in water stress for irrigation in the the southern Plains, which will lead to greater yields of irrigated sorghum and soybean.
“In predicting how climate will affect irrigated crop yields in the future, the researchers also consider factors such as population and economic growth, as well as competing demands for water from various socioeconomic sectors, which are themselves projected to change as the climate warms. … To do this, the researchers used a model of 99 major river basins in the country, which they combined with the MIT Integrated Global System Model-Community Atmosphere Model — a set of models that simulates the evolution of economic, demographic, trade, and technological processes.”
The study reiterates a point that many in the climate research sector have made in recent years: the Southwestern US, along with the mountain states, will be facing increasingly bad conditions as time goes by. This will lead directly to mass migrations out of the regions in question, to other already overpopulated parts of the country. Mass migrations out of coastal regions will add to this social disaster, as will falling agricultural yields themselves.
The new findings are detailed in a paper published in the journal Earth’s Future.