It’s not surprising that more urban trees lower the levels of heat and pollution. Although many cities maintain tree-planting programs, not all canopies have equivalent value. A new analysis from the American Forests conservation organization states that the U.S needs to plant more than half a billion trees across 500 metropolitan areas and 150,000 local communities. A new Tree Equity Score data tool allows users to see where urban trees exist and where they don’t. American Forests identified 20 large American cities that are lacking in canopies to protect their populations from hotter temperatures. Tree canopies are particularly effective in reducing health stress associated with urban heat “islands”.

It was also found that a pattern of inequitable distribution of trees has deprived many communities of the health and other benefits that sufficient tree cover can deliver. Communities of color have 33 percent less tree canopy on average than majority white communities. Jad Daley, American Forests president and CEO, says, “We need to make sure the trees go where the people are, and more than 70 percent of the people live in cities or suburbs, so it’s a place-based problem with a place-based solution.”