Midwest Agriculture and Economic Risks of Climate Change
A study in Iowa suggests that increased high temperatures will have a negative effect on crops. From the Des Moines Register:
The report’s grim assessment for the state, designed to look at the business risks from climate change, is similarly gloomy for other Midwest states and their largest cities, including Chicago, St. Louis, Indianapolis and Minneapolis.
Agriculture will be particularly hurt by climate change, it said, with corn, soybeans and wheat yields slashed as much as 85 percent by the next century in the leading farm states of Iowa, Illinois, Indiana and Missouri. Livestock also is expected to experience reduced productivity and other challenges.
Climate has a big say in crop yield variability
The University of Minnesota Institute on the Environment reports on a study published in Nature Climate Change:
What impact will future climate change have on food supply? That depends in part on the extent to which variations in crop yield are attributable to variations in climate. A new report from researchers at IonE’s Gobal Landscapes Initiative has found that climate variability historically accounts for one-third of yield variability for maize, rice, wheat and soybeans worldwide — the equivalent of 36 million metric tons of food each year. This provides valuable information planners and policy makers can use to target efforts to stabilize farmer income and food supply and so boost food security in a warming world.
Rising temperatures reduce global wheat production
Crop models are essential tools for assessing the threat of climate change to local and global food production1. Present models used to predict wheat grain yield are highly uncertain when simulating how crops respond to temperature2. Here we systematically tested 30 different wheat crop models of the Agricultural Model Intercomparison and Improvement Project against field experiments in which growing season mean temperatures ranged from 15 °C to 32 °C, including experiments with artificial heating. Many models simulated yields well, but were less accurate at higher temperatures. The model ensemble median was consistently more accurate in simulating the crop temperature response than any single model, regardless of the input information used. Extrapolating the model ensemble temperature response indicates that warming is already slowing yield gains at a majority of wheat-growing locations. Global wheat production is estimated to fall by 6% for each °C of further temperature increase and become more variable over space and time.