Tennessee is 42,143 sq. mi. (109,150 km.) in size with inland water making up 926 sq. mi. (2,398 sq. km.) Tennessee’s average elevation is 900 ft. (274 m.) above sea level, with a range in elevation from 178 ft. above sea level on the Mississippi River to 6,643 ft. (2,025 m.) at Clingman’s Dome. The variety of topographic features includes mountains, forested ridges, cultivated valleys, rugged plateau with valleys cut by streams, and the Highland Rim (an upland plain surrounds the Nashville Basin, and the Tennessee River separates the Highland Rim from the relatively flat coastal plain in the western part of Tennessee that extends almost to the low-lying area on the Mississippi River, which forms Tennessee’s western border). The major rivers are the Mississippi, the Tennessee River, and the Cumberland River, along with many tributaries. Natural lakes and reservoirs store water.
Tennessee has hot summers, mild winters, and abundant precipitation, with variations based on region. West Tennessee (the Gulf Coastal plain), Middle Tennessee (Highland Rim and Nashville Basin is made up of the Highland Rim [mountains] and East Tennessee [mountainous high region]). Average July temperatures range from less than 70 degrees F (21 degrees C) in the Blue Ridge region to 80 degrees F (27 degrees C) in Nashville and Memphis, and even summer nights can be warm and muggy in central and western Tennessee, with cooler temperatures in the eastern mountains. Average January temperatures range from freezing in the eastern mountains to 42 degrees F (22 degrees C) in the southwestern region. The highest temperature recorded in the state is 113 degrees F (45 degrees C) on August 9, 1930, and the lowest temperature recorded in the state is 32 degrees F (0 degrees C) on December 30, 1917. The average annual precipitation is 52 in. or 132 cm. (ranging from 60 in. or 152 cm. in mountain areas to 45 in. or 114 cm. in protected ridges and valleys). Severe blizzards rarely hit Tennessee, but some snow falls every year. West Tennessee receives about 5 in. (13 cm.), and the east can expect twice as much. The precipitation is made up of a combination of rain, snow, and sleet. Heavy rain falls in March and April, causing rivers to overflow their banks.
Tobacco is grown in much of the state. Western Tennessee is the largest agriculture region, with crops of cotton, corn, soybeans, tobacco, and others. Livestock (cattle, sheep, hogs, and poultry) predominates in the Nashville Basin, as well as dairy farming. Crops grown in the region are used to feed the livestock, except tobacco, which is a cash crop. Tennessee’s electricity is generated by coal-fired, nuclear power, and hydroelectric plants.
Although climate models vary on predicted temperature increase for Tennessee, estimates range from 1-5 degrees F (1.8-9 degrees C) in all seasons. Precipitation is estimated to increase only slightly in winter, perhaps 10-30 percent in spring and autumn and by 10-50 percent in summer. This increased rainfall could increase flooding (already a concern in the mountains in eastern Tennessee, in unregulated streams, and in growing urban areas near Chattanooga, Nashville, and Memphis).
With changes in climate, the extent of forested areas in Tennessee could change little or decline slightly, though the types of trees would be likely to change. Pine and scrub oaks would replace eastern hardwoods. The success of tree planting in environmental restoration areas (as in around mines) might decrease. Increased temperatures could pose a risk of wildfires. The agriculture may change little, however, with cotton yields unaffected and corn and hay yields possibly increasing.
If rainfall and runoff increase in the Tennessee region, then higher stream flows and lake levels could benefit hydropower production, enhance recreational opportunities, and improve water availability for water supplies. Increased water flow would dilute pollutants, though increased runoff including pesticides and fertilizers may shift levels of contamination higher, with the river basins in western Tennessee being especially susceptible.
Flooding increases the possibility of contamination of water supplies by sediment erosion, increased levels of pesticides and fertilizers, and runoff from grazing, mining, and urban areas.
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).
On the basis of energy consumption data from the Energy Information Administration, State Energy Consumption, Price, and Expenditure Estimates, released June 1, 2007, indicate Tennessee’s total CO2 emissions from fossil fuel combustion for 2004 were 125.38 million metric tons CO2, made up of contributions from: commercial sources (3.72 million metric tons CO2), industrial sources (20.41 million metric tons CO2), residential sources (4.41 million metric tons CO2), transportation sources (44.93 million metric tons CO2), and electric power sources (51.90 million metric tons CO2).
Tennessee 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. The Tennessee Environmental Council is including climate change strategy in their meetings.
Tennessee participates in a program called Rebuild America—an organization committed to assisting state and local government and school systems to implement energy-saving improvements. The Tennessee Valley Authority (TVA) has developed a program called Green Power Switch that enables customers to purchase 150-kilowatt-hour blocks of renewable energy (making up about 12 percent of a typical household’s monthly energy consumption). In addition, TVA must meet federal and other environmental statutes and regulations for air and water quality as well as managing the disposal of wastes (including hazardous materials). These regulations are becoming more stringent with clean air requirements and reducing greenhouse gas emissions.
Federal and state agencies are responsible for conservation inducing forest management and environmental protection including protecting against soil erosion and water and air quality.
