Living near parks, trees, water, and other green and blue spaces is good for your body and mind. Mayors from big cities worldwide, part of the C40 Cities Climate Leadership Group, signed a promise in 2021. They want 30% of each city covered in green spaces and 70% of people to have a park or nature nearby by 2030.

A study from George Washington University shows most of these cities met the green goal, but less than half reached the accessibility goal. They used satellite images to check the spaces in each city and found 80% met the green target, but only 47% made nature easily accessible for 70% of residents. Some cities have parks bunched up, while others spread them out.

Urban greenery

Most studies on green spaces and health use a measure called the normalized difference vegetation index. It checks plant density but doesn’t cover how easy it is to get to a park or what type of park it is. There’s no standard way to measure water spaces.

To track city progress, the researchers made a new way. They used satellite pictures to see where natural spaces are in each city. This helped them use different measures to see if cities were reaching the goals they promised.

In the future, they plan to use their method to see how more parks and nature in cities can make people healthier.