PT - JOURNAL ARTICLE AU - James R. Simpson TI - Urban Forest Impacts on Regional Cooling and Heating Energy Use: Sacramento County Case Study AID - 10.48044/jauf.1998.025 DP - 1998 Jul 01 TA - Arboriculture & Urban Forestry (AUF) PG - 201--214 VI - 24 IP - 4 4099 - http://auf.isa-arbor.com/content/24/4/201.short 4100 - http://auf.isa-arbor.com/content/24/4/201.full SO - JOA1998 Jul 01; 24 AB - Urban forests impact energy use for cooling and heating as a result of their moderating influence on climate. To evaluate the regional magnitude of these impacts, a large-scale analysis framework was developed and applied to Sacramento County, California, as a case study. Heating, cooling, and peak electrical energy use changes resulting from modification of solar radiation, air temperature, and wind speed by the existing urban forest were estimated for representative residential and commercial buildings. This is combined with building age and size, canopy and tree cover, and tree density (trees/ha) for 71 county subdivisions. Annual cooling savings are approximately 157 GWh (US$18.5 million) per year—12% of total air conditioning in the county. Net effects on heating are small, with 145 TJ (US$1.3 million) saved annually. Peak energy-use reductions result in avoided costs of US$6 million. The resulting large-scale analysis incorporates a manageable level of detail not previously available. Sensitivity of results to selected input data is demonstrated.