You may not think of New York City as an excessively green place, but life has found a way into every nook and cranny of the Big Apple not taken up by concrete. There’s so much green, in fact, that on certain summer days New York’s plant life reduce CO2 by up to 40 percent—sometimes knocking out an entire day’s worth of traffic emissions.

Researchers originally tried to calculate the effects of New York City’s parks on emissions, but that wasn’t telling the whole story. Only 10 percent of New York is designated as a city park, after all. By looking block by block, researchers were able to determine that nearly one third of New York is covered by some sort of leafy life—down to small gardens and single trees. The study comes from the scientific journal by way of :

“Most people have assumed that New York City is just a grey box,” Roísín Commane, a Columbia University researcher and coauthor of the paper, said in a . “But just because there’s a concrete sidewalk somewhere doesn’t mean there’s not also a tree that’s shading it.”

Scientists determined that tree canopies cover some 22 percent of New York, while shrubs and grasses cover another 12 percent. They estimated the total amount of carbon dioxide taken up by plants in the summer, when New York is at its most green, and compared it with data on local carbon dioxide levels gathered from instruments taking measurements on a continuous basis.

Carbon dioxide levels in the city followed a predictable pattern, researchers found. Levels would ramp up in the morning as the city got to work, and then slowly dissipate throughout the days as the plants sucked up emissions.

“There is a lot more greenery than we thought, and that’s what drives our conclusion,” Dandan Wei, a postdoctoral researcher at Columbia and lead author of the study, said in a statement to Yale Environment. “This tells us that the ecosystem matters in New York City, and if it matters here, it probably matters everywhere else.”

New York isn’t just letting the plants do all the work of cleaning up the city’s air. It announced that all new cars sold in the state must be hybrids or EVs by 2035. The city also introduced in an effort to cut down on traffic and smog. New York also pays bounty hunters who report , hoping fines will cut down on needless street-level pollution.