Briefs: Impact of shade trees on electricity use

A recent study conducted on 460 single-family homes in Sacramento, California, shows that shade trees on the west and south sides of a house can reduce the summer electricity bill by about USD 2500 a year. Of course, the fact that shade can reduce air-conditioning needs is not groundbreaking news, but this study is the first to give precise facts and figures on several aspects such as optimal tree locations. For instance, a tree planted on the west side of a house can reduce net carbon emissions from summertime electricity use by 30% over a 100-year period.