Annual net carbon uptake by urban trees in places like New York City's Central Park and Golden Gate Park in San Francisco is estimated at 21 million tons and $1.5 billion in economic benefit, researcher Dave Nowak reported in the journal Environmental Pollution.
Nowak and his forest service colleagues used urban tree field data from 28 cities and six states and national tree cover data to estimate total carbon storage in the nation's urban areas.
"With expanding urbanization, city trees and forests are becoming increasingly important to sustain the health and well-being of our environment and our communities," U.S. Forest Service Chief Tom Tidwell said.
"Carbon storage is just one of the many benefits provided by the hardest working trees in America," he said. "I hope this study will encourage people to look at their neighborhood trees a little differently, and start thinking about ways they can help care for their own urban forests."
The researchers said the states with the greatest amount of carbon stored by trees in urban areas are Texas with 49.8 million tons, Florida with 47.3 million, Georgia with 42.4 million, Massachusetts with 39.6 million and North Carolina with 37.5 million tons.