IOWA HAS AN area of 56,272 sq. mi. (145,744 sq. km.), with inland water making up 402 sq. mi. (1,041 sq. km.), including 31 natural lakes most formed by glaciers and reservoirs. Iowa's average elevation is 1,100 ft. (335 m.) above sea level, with a range in elevation from 480 ft. (146 m.) at the Mississippi River, to 1,670 ft. (509 m.) in Osceola County. Iowa has 2 million acres of forested land. The topography is central lowland, part of the interior plains. Iowa's rivers drain into the Mississippi River system. Iowa has many small lakes, and dams on smaller rivers have created several reservoirs. Dams on the Mississippi River have created large reservoirs on the eastern state line formed by the Mississippi River.
Iowa's climate is fairly uniform throughout the state, with hot, muggy summers, and harsh winters. Des Moines's average January temperature is 20 degrees F (minus 6 degrees C) and the average July temperature is 76 degrees F (24 degrees C) (with warmer daytime temperatures in the high 80s to low 90s F, or 27-32 degrees C). The highest temperature recorded in the state was 118 degrees F (48 degrees C) on July 20, 1934, and minus 47 degrees F (minus 44 degrees C) is the lowest temperature recorded in the state on February 3, 1996. The annual precipitation is between 26-36 in. (66-91 cm.) around the state, with more precipitation in the eastern part of the state. With no natural barriers like mountains, Iowa experiences the full sweep of winds.
Iowa's major crop is corn (hybrid corn developed to resist disease and drought). Hot and muggy summers and a long growing season (170 days in the south and 140 days in the north) lead to a good corn harvest. Beef, pork, wheat, soybeans, and apples are also major agri cultural contributions to the economy. Major industries include chemicals, machinery, and electrical equipment manufacturing. Iowa has large coal reserves and most of the coal mined is burned to make electricity.
Iowa experienced a sample of possible impact of climate change with the Great Flood of 1993. Heavy rain (Des Moines reported 29.67 in. of rain) and snow runoff raised the Missouri, Mississippi, Des Moines, Cedar, and Iowa rivers and many smaller streams, causing severe flooding in much of the state.
Climate models vary on temperature increase for Iowa, from 2-7 degrees F (1-4 degrees C) in autumn and winter, from 1-4 degrees F (0.5-2 degrees C) in summer, and from 1-5 degrees F (0.5-3 degrees C) in spring by the end of the 21st century. Potential risks include increase in frequency and intensity of summer and autumn rainfall, making flooding a possibility in many areas, made worse by difficult drainage and the increasing chance of topsoil erosion. Flooding and runoff could contaminate water supplies (with eroded soils and agricultural chemicals containing high concentrations of nitrates, pesticides, and soil nutrients). Changes within established ecosystems (wetlands, forest, cropland, and prairies) would affect wildlife, including breeding grounds of waterfowl and migratory birds. Human health risks include, but are not limited to, contracting certain infectious diseases from water contamination or disease-carrying vectors such as mosquitoes, ticks, and rodents. Warmer temperatures would increase the incidence of heat-related illnesses and lead to higher concentrations of ground-level ozone pollution, causing respiratory illnesses (diminished lung function, asthma, and respiratory inflammation).
Agriculture, the major source of the Iowa economy, may not be affected at lower temperature increases. Only if summer temperatures rise to the higher predicted levels and drier conditions become prevalent will livestock be affected by failure to gain weight and limited pasture yield. Iowa has the potential for an additional source of income selling emission credits achieved by carbon sequestration.
Based on energy consumption data from the Energy Information Administration's State Energy Consumption, Price, and Expenditure Estimates (SEDS) released June 1, 2007, Iowa's total carbon dioxide (CO2) emissions from fossil fuel combustion in million metric tons CO2 for 2004 were 80.20, made up of contributions from: commercial, 3.54; industrial, 15.58; residential, 4.77; transportation, 20.37; and electric power, 35.93.
Iowa established the Climate Change Advisory Group in April 2007 to assess climate change impact and develop a strategy for reducing greenhouse gas emissions. The Department of Natural Resources Air Quality must include greenhouse gas emissions estimates in construction permitting and emissions inventory programs. Iowa's 2002 Comprehensive Energy Plan Update required state facilities to purchase at least 10 percent of their electricity from renewable energy by 2005 and to reduce their energy consumption to 20 percent below 2000 levels. Iowa joined the Climate Registry, a voluntary national initiative to track, verify, and report greenhouse gas emissions, with acceptance of data from state agencies, corporations, and educational institutions, beginning in January 2008.
Iowa farmers are participating in a pilot program that pays them to store carbon in their soil by not tilling. The Chicago Climate Exchange program then sells carbon credits to utilities and other big carbon polluters to offset emissions. Conservation in Iowa began long before global warming became an issue. In 1972, Iowa established the first soil conservation cost-share program in the United States, and, in 1980, renewed the commitment to soil conservation with a 20-year schedule for soil-erosion prevention measures. In addition, research and education continue to decrease the use of chemicals in farming. The Iowa legislature also passed environmental protection bills to preserve ground water and air quality, with the task performed by the Department of Natural Resources.
sEE ALso: Carbon Sequestration; Iowa State University.
BIBLIoGRAPHY. A.N. Garwood, Weather America Latest Detailed Climatological Data for Over 4,000 Places and Rankings (Toucan Valley Publications, 1996); Iowa Department of Natural Resources, www.iowadnr.com (cited October 2007); W.A. Lyons, The Handy Weather Answer Book (Visible Ink, 1997).
Lyn Michaud Independent Scholar
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