Largely due to population growth, U.S. urban areas are steadily losing tree cover. According to a study in the May issue of Urban Forestry & Urban Greening, these metropolitan areas are undergoing a net loss of 36 million trees a year. Trees play an important role in reducing urban air pollution. They provide shade, which helps save energy costs for cooling, and thy capture carbon emissions. Studies show that tree cover provides many psychological benefits to people.
Between now and 2065, if present trends continue, the U.S. will add more than 75 million people to its current population of 327 million. Current levels of immigration would account for 95 percent of that growth, according to the Census Bureau.
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