In Summer, Denver gets hot — so hot that it’s considered one of the most intense urban heat islands in the U.S. A new initiative would require that many new buildings have green roofs to mitigate that heat. Critics of the policy, however, say the city should incentivize, not require, the so-called “living roofs.”
The initiative could go before voters in November, if petition gatherers collect enough signatures. It would modify the local building code to require urban gardens on the roofs of buildings over 25,000 square feet, the Denver Post reports. It would be similar to an ordinance adopted recently by the city of San Francisco, which forced certain developers to incorporate solar panels or rooftop gardens into their building design.
Philadelphia has also written green roofs into local policy with a numbers-driven twist — its director of sustainability last year said that local officials would use data to find the hottest areas in the city and install green roofs there. According to the EPA, “on hot summer days, the surface temperature of a green roof can be cooler than the air temperature, whereas the surface of a conventional rooftop can be up to 90°F (50°C) warmer.”
Advocates for the policy say the 2016 election is behind their push.
“I’m very passionate about climate change, and with our recent election, it’s time for our citizens to take the initiative and battle some of the climate changes we are experiencing,” Madison Backens, a biology student at the University of Colorado Denver and the initiative’s primary sponsor, told the Post.
A number of other cities, including Chicago, Seattle and Portland, have offered incentives to encourage green roofs instead of mandating them.
Rachel Dovey is an award-winning freelance writer and former USC Annenberg fellow living at the northern tip of California’s Bay Area. She writes about infrastructure, water and climate change and has been published by Bust, Wired, Paste, SF Weekly, the East Bay Express and the North Bay Bohemian.