Most U.S. cities have tree-planting programs, but not all urban tree canopies are created equal, according to a new analysis from American Forests.

The conservation organization said today that the United States needs to plant more than a half-billion new trees to achieve an equitable urban canopy across nearly 500 metropolitan areas and 150,000 local communities.

The findings are based on a new "Tree Equity Score" data tool that allows users to see where urban trees exist, and where they don't. American Forests also identified 20 large U.S. cities that are lagging in urban forest canopies that would protect their most vulnerable populations from hotter temperatures.

"The findings confirm a disturbing pattern of inequitable distribution of trees that has deprived many communities of color of the health and other benefits that sufficient tree cover can deliver," American Forests said.

For example, communities of color have 33% less tree canopy on average than majority white communities, the analysis revealed. And neighborhoods with 90% or more of their residents living in poverty have 41% less tree canopy than communities with only 10% or less of the population in poverty. (Greenwire, Sept. 16, 2020).

"The scale and pace at which trees are planted or naturally regenerate must significantly increase if trees are to continue to make people healthier or slow effects of climate change," Ian Leahy, American Forests' vice president for urban forestry, said in a statement.

Achieving "tree equity" nationally would require planting 522 million trees in places with populations of 50,000 or greater, American Forests said. As those trees mature, they would mitigate 56,613 tons of particulate pollution and absorb 9.3 million tons of carbon dioxide — the equivalent of taking 92 million cars off the roads, American Forests said.

The report identified several cities that would benefit from more equitable tree cover. Those include the five most populated cities in the United States — New York, Los Angeles, Chicago, Houston and Phoenix — and a handful of smaller cities such as Fresno, Calif.; Jacksonville, Fla.; and Oklahoma City.

Tree canopies are particularly good at reducing health stress associated with urban heat islands. These areas often are much hotter than surrounding neighborhoods — a condition caused by a lack of trees and the absorption of heat by buildings, streets and parking lots.

Scientists say urban heat islands can cause temperatures to be 5 to 7 degrees warmer during the day and as much as 22 degrees warmer at night.

This creates a dangerous health risk. Under current climate warming trajectories, heat-related deaths from 2031 to 2050 could be 57% higher than from 1971 to 2000, American Forests said.

"We need to make sure the trees go where the people are," said Jad Daley, American Forests president and CEO. "And more than 70% of the people live in cities or suburbs, so it's a place-based problem with a place-based solution."

He also stressed the need for local, state and federal lawmakers and nonprofits to fund the protection of existing trees and plant new ones.

Reprinted from E&E News with permission from POLITICO, LLC. Copyright 2021. E&E News provides essential news for energy and environment professionals.