Climate change in the Midwest is causing winters to be milder, on average, and is increasing the frequency and severity of heavy precipitation events. These changes are increasing the prevalence and range of pests and invasive species, which has wide-ranging impacts on human health, food security, and the management of important ecosystems.
Climate Implications – Invasive Species and Pests
Short, mild winters and wetter weather are increasing populations of pest insects such as mosquitos and ticks. These increases in pest insects are projected to double the national annual cases of West Nile Virus by 2040 and increase annual Lyme disease cases by 20 percent.
Increased spring precipitation and humidity is causing fungal outbreaks in agriculture to be more widespread, frequent, and impactful. Diseases such as Bacterial Spot, Anthracnose, and Southern Rust may become more common in the Midwest, causing food crop yield losses and negatively impacting food security. Increased disease prevalence, combined with other threats that crops face such as drought, flooding, and heat stress, could increase crop failures, endanger food security, and raise food prices.
Warmer temperatures, extended growing seasons, and increased rainfall favor fast-growing and invasive species. In the Great Lakes, Alewife, zebra, and quagga mussels may cause even more damage to the native ecosystem by taking advantage of increased nutrient levels caused by increasing fertilizer runoff. Sea lamprey, which feed on game fish, are expected to grow larger, and produce more eggs, further stressing fisheries around the Great Lakes. Commercial and sport fishing could be impacted by these invasive species. Similarly, forest management will become more difficult as southern invasive plants such as Chinese privet, kudzu, bush honeysuckle, and more creep further north, pushing out native species.