In heavily-paved urban areas, a good downpour can quickly overwhelm a municipal sewer system. But an ancient building technique that’s popular in Europe suggests a way to alleviate the problem: add a touch of green to the roof. Roof-top vegetation provides insulation, cooling and waterproofing; and it can help prevent runoff, too. Several German cities already require so-called “green roofs” on all new commercial buildings. Here in the U.S., the idea is just catching on. And we found one of its proponents. Tom Liptan is a storm water specialist for Portland, Oregon — a city where sewer overflows are common. Two years ago Mr. Liptan built a green roof on top of his garage.
The World is an independent newsroom. We’re not funded by billionaires; instead, we rely on readers and listeners like you. As a listener, you’re a crucial part of our team and our global community. Your support is vital to running our nonprofit newsroom, and we can’t do this work without you. Will you support The World with a gift today? Donations made between now and Dec. 31 will be matched 1:1. Thanks for investing in our work!