How Trees and Shrubs in New York City Help Purify the Air.

 As advocates push the city to plant more trees, new research shows the role of urban green spaces in absorbing carbon emissions.

Andrew Reinman looked beyond the buildings of a recent Harlem era and focused instead on the trees. Along St Nicholas Terrace, Dr. Reinman noticed rows of London planes and oaks embedded in the cement. In a garden overgrown with petals of a river birch, he saw a savannah.

New York is a surprisingly green city for a city that can't be separated from its towers of glass and steel. And its green spaces may affect a city's carbon footprint much more than previously known, according to new research by Dr. Reinman, a forest ecologist at the City University of New York, and colleagues.