As Jeff Gahan's chainsaws coo and whirr: "What Are Trees Worth to Cities?"

Take it from me: They're absolutely doomed.

Here's your trade-off: Finally we'll have a walkable city -- just one without any shade trees whatever. That's precisely the ticket for an urban heat island, don't you think? But we all have air conditioned cars, right?

Hmm.

Maybe trees should consider becoming visionary level donors to the local Democratic Party. Mighty shortsighted of them failing to grasp the way things work.

What Are Trees Worth to Cities? Meet the U.S. Forest Service scientist putting a dollar value on urban forests, by Laura Bliss (City Lab)

David Nowak whittles down 30 years of studying the economic value of forests to this advice: If you can only plant one tree, plant it in a city.

After all, in an era of overwhelming need for urban infrastructure improvements, trees offer cities some of the best bang for their buck. Trees remove carbon dioxide, filter air pollution, and produce oxygen. They absorb rainwater, UV radiation, and noise. They slow down traffic, improve property values, and reduce human stress and mental fatigue. And they provide shade, which means we have to use less energy to cool down.

“Trees help us avoid emissions in the first place, in addition to taking out carbon,” says Nowak, a lead researcher at the U.S. Forest Service’s Northern Research Station in Syracuse, New York. “It’s a big problem that they help us solve.”