Trees can make a city sidewalk prettier, sure. But that’s not even their best trick. A growing pile of research suggests that planting more urban trees, if done right, could save tens of thousands of lives around the world each year — by soaking up pollution and cooling down deadly heat waves.

In fact, as a fascinating new report from the Nature Conservancy details, a well-targeted tree campaign could be of the smartest investments a hot, polluted city can make. Which seems important, given that the world’s cities will add about 2 billion people this century, and they’re only getting hotter.

“A lot of cities still think of trees as just ornamentation,” says Rob McDonald, the lead scientist for the Nature Conservancy’s Global Cities program and a co-author of the report. “But they really do so much more than that. And the evidence suggests that we should start thinking of trees as a crucial part of our public-health infrastructure.”

Read more at  Why planting more trees is one of the smartest things a city can do – Vox