Trees and urban forests cool the environment by direct shade, which lowers surface and air temperature, and by evapotranspiration. The lowering of temperatures reduces energy consumption, and thus the amount of carbon emissions at the power plant. In this way, carbon savings are achieved from reduced energy consumption.
The exact calculation of carbon savings from cooling effects is hard to pinpoint, because savings will vary based on density of tree canopy and spacing in an urban forest. In addition, the maintenance of trees leads to carbon emissions, so it is important to consider the net effects on the carbon balance of a community. In one example, according to the City of Minneapolis, Minnesota Municipal Tree Resource Analysis, street trees in Minneapolis reduce annual CO2 emissions by 27,611 tons through energy savings. The study showed a release of 2,012 tons of CO2 from decomposition and tree care activities annually.
|Photo Credit: Raina Sheridan|
McPherson, Gregory E., James R. Simpson, Paula J. Peper, Scott E. Maco, Shelley L. Gardner, Shuana L. Cozad, and Qingfu Xiao. City of Minneapolis, Minnesota Municipal Tree Resource Analysis. Tech. Center for Urban Forest Research, Pacific Southwest Research Station, USDA Forest Service. June 2005. http://www.fs.fed.us/psw/programs/uesd/uep/products/2/cufr645_MinneapolisMFRA.pdf