Agriculture in the entire Great Lakes region will be hurt by a changing climate, says a new report from the University of Illinois and the Union of Concerned Scientists (UCS). Changing precipitation patterns, more extreme rainfall events, rising ozone concentrations, and an increase in pests and pathogens will disrupt current farming practices throughout the region.
"Farmers in the region are already suffering from wetter spring and fall weather, and the intensity of rainstorms has also increased," says Michelle Wander, University of Illinois Associate Professor of soil fertility and co-author of Impacts on Agriculture: Our Region's Vital Economic Sector. "For farmers, these changes mean crop losses and higher costs."
Wander and co-author Steve Clemmer of UCS also agree that agriculture can be an important part of the solution to global warming. "Practical solutions exist today for farmers to reduce heat-trapping gas emissions from their operations," says Clemmer. "Along with addressing climate change, many of the available solutions also reduce soil erosion, improve air and water quality, and bring additional revenue to farmers and rural communities."
Maximum daily temperatures could rise by 5 to l2 degrees in winter and 5 to 20 degrees in summer in the Great Lakes region. Drought frequency will likely increase due to the combination of higher summer temperatures, evaporation, runoff from intense rainfall events, and decline in summer precipitation.
Effects vary by region
Of serious concern, according to the report, are changing precipitation patterns. Crop production in the region is already suffering from problems related to both excess and insufficient moisture, and these problems will only worsen as climate change progresses. The combination of high heat and flooding is especially lethal to corn and soybeans.
Increasing carbon dioxide levels in the atmosphere trap heat and contribute to climate change. Increased carbon dioxide and earlier planting dates could boost soybean yields in the central and northern portions of the region, but losses are expected in southern areas. Soybean yield variability is also expected to increase. Any increases may be offset or negated by rising ozone concentrations that result from human activities such as the application of nitrogen fertilizers and burning of fossil fuels.
"Ozone is particularly damaging to soybeans and horticultural crops, and soybean yields in the region are already reduced approximately 25% by ozone damage. But high heat and associated heat stress will also reduce corn yields in the south and western parts of the region," says Wander.
Climate changes will also affect the outlook for damaging crop pests. Ranges for many pests, including bean leaf beetles and corn borer, have already expanded northward. Hot, dry summers may worsen yield losses due to corn rootworm larvae. Excess moisture and humidity can increase the frequency of gray leaf spot, crazy top, and smut in corn; later in the century, drought will likely increase the damage inflicted by soybean cyst nematodes.
Solutions include renewable energy funding and conservation practices
Wander and Clemmer, Research Director for UCS' Clean Energy Program, collaborated to develop policy recommendations that would address heat-trapping emissions. They recommend increased funding for energy efficiency and renewable-energy projects.
"Over the past two years, the USDA has provided $44 million from the Farm Bill to support 280 renewable-energy and energy efficiency projects on American farms," says Clemmer. "Projects funded in the first year alone will produce enough electricity to supply the annual needs of 30,000 households while creating 1,300 new jobs and greatly reducing carbon dioxide emissions."
Certain best practices in soil management such as no-till, reduced tillage, and crop diversification including the use of cover crops could enhance short-term soil carbon storage.
Wander and Clemmer also recommend incentives to sequester carbon on marginal lands and renewable energy standards for electricity and transportation. Clemmer says competition from renewable energy would also lower natural gas prices, thereby lowering fertilizer prices.