Plants grow on a rooftop farm in Greenpoint, New York. Photo: Mike Di Paola/Getty Images

Click the image above for the story in The Guardian:

Advocates say green infrastructure isn’t just about being green — it makes financial sense, as well. Its cost-effectiveness depends on how benefits are assigned and valued, and over how long a time scale, but green has been shown to be cheaper than gray.

A 2012 study by American Rivers, ECONorthwest, and other groups examined 479 projects around the country. About a quarter of the projects were more expensive, they concluded, and 31 percent cost the same; more than 44 percent brought the costs down, in some cases substantially. New York City, for example, expects to save $1.5 billion over the next 20 years by using green infrastructure.