Midwest Climate Change
Ohio, Missouri, Iowa, Illinois, Indiana, Michigan, Minnesota and Wisconsin
Information from the U.S. Global Change Research Program, June, 2009
Rising Temperature and More Precipitation
The Midwest climate region includes the states of Minnesota, Wisconsin,
Michigan, Ohio, Indiana, Illinois, Iowa and Missouri. Climate in this
region is strongly influenced by the presence of the Great Lakes and the
location of the region in the middle of the North American Continent. Without
the temperature-moderating effect of a nearby ocean the region has large
seasonal swings in temperature.
In the past few decades there has been a noticeable increase in average
temperatures. The most dramatic change has been higher winter temperatures
and an extension of the frost-free growing season by over one week - mainly
due to an earlier date for the last spring frost.
Changes in precipitation have been dramatic. Heavy rainstorms now occur
twice as often as they did a century ago. Summer and winter precipitation
has been significantly above average for the last three decades, the wettest
period in the past century. There have been two record-breaking floods in
the past 15 years, a significant decrease in lake ice, and heat waves have
been more frequent and longer than any time other than the great dust bowl
of the 1930's.
|More Heavy Downpours, Higher Evaporation|
The likely increase in precipitation in winter and spring, more heavy downpours, and greater evaporation in summer would lead to more periods of both floods and water deficits.
The projected pattern of increasing precipitation in winter and spring and heavy downpours is expected to lead to more frequent flooding, increasing infrastructure damage, and impacts on human health. Heavy downpours can overload drainage systems and water treatment facilities, increasing the risk of waterborne diseases. In summer, with increasing evaporation and longer periods between rainfalls, the likelihood of drought will increase and water levels in rivers and wetlands are likely to decline. Photo copyright by iStockPhoto / S. Klaschik.
|Diseases, Pests and Invasive Species|
Native species are very likely to face increasing threats from rapidly changing climate conditions, pests, diseases, and invasive species moving in from warmer regions.
All major groups of animals including birds, mammals, amphibians, reptiles, and insects will be affected by climate change impacts on local populations and by competition from species moving into the Midwest. The potential for animals to shift their ranges to keep pace with the changing climate will be inhibited by major urban areas and the presence of the Great Lakes. Photo copyright by iStockPhoto / D. Allen.
|Heat Waves Impact People and Livestock|
While the longer growing season provides the potential for increased crop yields, increases in heat waves, floods, droughts, insects, and weeds will present increasing challenges to managing crops, livestock, and forests.
Spring flooding is likely to delay planting. An increase in disease-causing pathogens, insect pests, and weeds cause additional challenges for agriculture. Livestock production is expected to become more costly as higher temperatures stress livestock, decreasing productivity and increasing costs associated with the needed ventilation and cooling equipment.
|Climate change will have a number of severe impacts on the midwestern states of Ohio, Missouri, Iowa, Illinois, Indiana, Michigan, Minnesota and Wisconsin. This page illustrates a number of the more significant impacts. Map by Geology.com and MapResources.
|Public Health & Quality of Life Impact|
During the summer, public health and quality of life, especially in cities, will be negatively affected by increasing heat waves, reduced air quality, and increasing insect and waterborne diseases. In the winter, warming will have mixed impacts.
Heat waves that are more frequent, more severe, and longer-lasting are projected. The frequency of hot days and the length of the heat-wave season will both be more than twice as great under a higher emissions scenario than a lower one (see full report for information on emission scenarios). Insects such as ticks and mosquitoes that carry disease will survive winters more easily and produce larger populations in a warmer Midwest.
Significant reductions in Great Lakes water levels, which are projected under higher emissions scenarios, lead to impacts on shipping, infrastructure, beaches, and ecosystems.
Higher temperatures will mean more evaporation and hence a likely reduction in Great Lakes water levels. Reduced lake ice increases evaporation in winter, contributing to the decline. This will affect shipping, ecosystems, recreation, infrastructure, and dredging requirements. Costs will include lost recreation and tourism dollars and increased repair and maintenance costs. Photo copyright by iStockPhoto / R. Mansi.