Tennessee, land of country music and smoky mountains, is home to 6.83 million people over 42,144 square miles. Tennessee’s geography is extremely unique, with the Appalachian and Great Smoky Mountains by the eastern North Carolinian border and a relatively flat half by the Mississippi River to the west on the Missouri and Arkansas border. Tennessee is sandwiched between the milder-climates of states like Kentucky and Virginia and the Deep South climate of Georgia, Alabama, and Mississippi. Tennessee has 10 official state songs. The first is “My Homeland, Tennessee,” adopted in 1925, but the most famous one is “Rocky Top,” adopted in 1982.
Tennessee is an interesting case when it comes to climate change. Natural cycles and sulfates in the air prevented much of Tennessee from warming during the last century. Sulfates are air pollutants that reflect sunlight back into space, preventing the greenhouse effect. Now, sulfate emissions are declining and Tennessee is warming.
Annual precipitation in Tennessee has increased by 5% since the first half of the 20th century. However, rising temperatures cause increased evaporation, so although rainfall is expected to continue to rise, the total amount of water running into rivers or recharging ground water each year is likely to decline 2.5-5%. Droughts are likely to be more severe because periods without rain will be longer, and very hot days will be more frequent.
When rainfall increases but periods without rain get longer, flooding is inevitable. Flooding is already becoming more severe. Since 1958, the amount of precipitation falling during heavy rainstorms alone has increased by a full 27% in the Southeast, and the trend is likely to continue.
Severe droughts and more hot days reduce farm yields, especially in the western half of Tennessee. These hot days will particularly impact corn and soybeans, two major cash crops. Warmer temperatures are also likely to reduce the productivity of dairy and other cattle farms.
Another less obvious problem with droughts and rainstorms is damage to Tennessee’s river trade. During droughts, the Tennessee Valley Authority and the Corps of Engineers release water from dams to keep the Tennessee and Cumberland rivers navigable. These rivers support $35 billion in annual shipping. The agencies try to keep channels at least eleven feet deep, because lower river levels can force barges to carry smaller loads, which increases transportation costs.
Tennessee’s government leaves something to be desired in terms of climate change legislation. The state’s current governor has made statements in the past against climate change, equivocating, “There are a lot of studies that have had a lot of different outcomes,” when asked if he believed that climate change was real. However, former Tennessee governors and local state authorities have taken minor action. In 2009, Tennessee commissioned an assessment of the impacts of climate change on the state (though it was mandated by Congress). The city of Memphis did highlight climate change adaptation in its GreenPrint area study in 2015, which spells out a vision for the greater Memphis region over the next 25 years. However, as of now, the state of Tennessee has no climate change adaptation plan.
In energy consumption, Tennessee ranks among the top one-third of the states and near the median of energy consumption per capita. The transportation sector alone accounts for 30% of the state’s energy usage. Manufacturing takes slightly under another 30% of the state’s consumption, and most of the rest of the state’s energy goes to heating and cooling in the residential sector.The Tennessee Valley Authority (TVA) owns more than 90% of Tennessee’s electricity generating capacity, including 19 hydroelectric dams, seven natural-gas fired plants, four coal-fired power plants, two nuclear power plants, and one pumped-storage hydroelectric plant. TVA also has one wind farm and seven small solar farms. Nuclear power accounts for 44% of the state’s generation. Coal accounts for 23%, natural gas at 20%, and hydroelectric power at 12%. All of the rest (1%) of Tennessee’s generation came from other renewable power sources. Biomass makes up the majority of that 1%, with solar energy making up the rest.
CREDIT: Senator Sheldon Whitehouse