Shade trees reduce building energy use and CO2 emissions from power plants

TitleShade trees reduce building energy use and CO2 emissions from power plants
Publication TypeJournal Article
Year of Publication2002
AuthorsAkbari, Hashem
JournalEnvironmental Pollution
Volume116
Issue1
PaginationS119-S126
Date Published03/2002
Keywordscarbon sequestration, cost-benefit analysis, Heat islands, Heating and cooling energy use, Shade trees, Smog
Abstract

Urban shade trees offer significant benefits in reducing building air-conditioning demand and improving urban air quality by reducing smog. The savings associated with these benefits vary by climate region and can be up to $200 per tree. The cost of planting trees and maintaining them can vary from $10 to $500 per tree. Tree-planting programs can be designed to have lower costs so that they offer potential savings to communities that plant trees. Our calculations suggest that urban trees play a major role in sequestering CO2 and thereby delay global warming. We estimate that a tree planted in Los Angeles avoids the combustion of 18 kg of carbon annually, even though it sequesters only 4.5–11 kg (as it would if growing in a forest). In this sense, one shade tree in Los Angeles is equivalent to three to five forest trees. In a recent analysis for Baton Rouge, Sacramento, and Salt Lake City, we estimated that planting an average of four shade trees per house (each with a top view cross section of 50 m2) would lead to an annual reduction in carbon emissions from power plants of 16,000, 41,000, and 9000 t, respectively (the per-tree reduction in carbon emissions is about 10–11 kg per year). These reductions only account for the direct reduction in the net cooling- and heating-energy use of buildings. Once the impact of the community cooling is included, these savings are increased by at least 25%.

Notes

0269-7491Added to JabRef: 2010.04.16

DOI10.1016/S0269-7491(01)00264-0