NYC's Greenery Eats Up All the CO2 From Its Cars, Trucks and Buses "And Then Some"

New York City's vegetation seems to absorb a lion's share of its carbon emissions via photosynthesis on summer days, according to researchers at New York City's own Ivy League school.

For the first time, the city's hidden greenery between buildings and on streets has been mapped by the environmental scientists from Columbia University and the City University of New York.

On many summer days, trees and grasses absorb all the carbon emissions produced by cars, trucks and buses, and then some.

Scientists were able to see minute bits of vegetation, from trees and small gardens in the brownstone backyard to individual foliage on the street, using new aerial radar imagery. The vegetation was left out of the NYC greenery maps due to the large tracts of grassland and forests in the city parks that only make up 10% of the total vegetation.

According to Rosn Commane, an atmospheric chemist who co-authored the paper, most people assume that New York City is biogenically dead. "Just because there's a concrete sidewalk somewhere doesn't mean there isn't a tree that's shading it."

The research team looked at carbon data from June to August and found that the Big Apple emitted over 13 million tons of carbon dioxide. It's not much of a shock that New York is the largest carbon emitter in the US and third largest in the world.

The researchers say that NYC's CO2 levels would be higher if it weren't for the city's large amount of greenery. When NYC is at its best, the vegetation ate up 85 percent of the carbon emissions.

The press release states that on many summer days, total carbon absorption equaled up to 40% of a summer afternoon's total emissions. The scientists saw carbon dioxide levels go up in the morning and go down in the afternoon, as traffic and other activities went on.

The conclusion has a huge caveat, it only happens in New York during the growing season from April to October. The growing season lasts longer in warmer cities.

Natural defenses against carbon emissions could be affected by these conclusions.

Dandan said in the release that there is a lot more greenery than they thought. If it matters here, it probably matters everywhere else.

Scientists say carbon dioxide seems to be making trees grow faster.