High air temperatures are a public health threat,causing 1300 deaths annually in the United States(US) along with heat-related morbidity and in-creased electricity consumption for air-conditioning. Increasing tree canopy cover has been proposed as one way to reduce urban air temperatures. This paper assembles tree cover and developed land-cover information for 97 US cities, housing 59 million people, and use regression relationships to analyze how much current urban tree cover reduces summer air temperatures and associated heat-related mortality, morbidity, as well as electricity consumption.

Currently, for the 97 cities studied, the total annual economic value of avoided mortality, morbidity, and electricity consumption is an estimated $1.3–2.9 billion , or $21–49 annually per capita. Applying our results to the entire US urban population, the authors estimate urban tree cover annually supplies heat-reduction services worth $5.3–12.1 billion.

• TAGS:
• Climate Change,
• Human Health,
• urban heat island