John Yang:

Goeing, a retired zookeeper, is among the hundreds of South Louisville residents getting trees, shrubs and other greenery over the next year.

It's part of a projected $15 million research project conducted by the University of Louisville and sponsored by the National Institutes of Health and The Nature Conservancy. It's called Green Heart Louisville.

Researchers say this project is the first of its kind, a large-scale scientific study of how trees and green spaces affect residents' health. It comes at a crucial time for the city of Louisville.

Between 2004 and 2012, the city lost an average of 54,000 trees a year to development, storms, pests, and old age. During that time, the tree canopy coverage in Louisville dropped to just 37 percent, well below other cities in the region. And since 1996, the American Lung Association has given the city a failing grade for air pollutants like ozone.

What's more, Louisville is one of the nation's fastest-warming urban heat islands. Parts of the city can be 10 degrees hotter than surrounding areas. Green Heart researchers think more trees could be a solution. They can improve air quality, cool neighborhoods, help combat global warming, and even muffle noise pollution.

Chris Chandler is The Nature Conservancy's urban conservation director in Kentucky.

When you look at a street like this, what do you see?