“When a rooftop has a green cover, comprised of plants in raised beds, tables, or trellises, it shades the apartments on the upper floor, preventing overheating, especially in buildings that lack proper insulation, as is often the case in informal settlements. Rooftop gardens also reduce the heat that concrete structures absorb throughout the day and then re-emit at night, keeping cities cooler overall.
In Jeddah, Saudi Arabia, one of the world’s hottest cities, a study showed that indoor air temperatures in buildings with rooftop gardens were as much as 12 degrees Fahrenheit cooler than those without gardens, even during the warmest hours of the day. That saves on energy, too, which can have knock-on environmental effects. Research also shows that even relatively small rooftop gardens can reduce surrounding air temperatures by more than half a degree Fahrenheit”
A Greenpoint building is part of a push to combat climate change and make the city more welcoming to wildlife.
Excerpt from this New York Times story:
Tall grasses glow in the afternoon sunlight. The last bees and butterflies of the season hover over goldenrod and asters. Silver orbs that look like alien spacecrafts shimmer nearby.
The wild-looking meadow is not in a rural outpost, but sandwiched between a sewage plant — the orbs are the tanks — and a parking lot packed with tractor-trailers. The plants perch atop the roof of a film production studio in the Greenpoint section of Brooklyn, beside a Superfund toxic-waste site.
As bird and insect populations plummet, sounding new alarms about the health of the natural world, one promising arena where humans can help is also a surprising one: cities. In New York, scientists and officials are calling for residents and companies to do their part, with projects as ambitious as the rooftop meadow and as simple as choosing native plants for home window boxes.
For some species, scientists say, cities can be more hospitable than rural and suburban areas, because fewer lawns and farms mean fewer pesticides. The green roof in Brooklyn, Kingsland Wildflowers at Broadway Stages, draws endangered monarch butterflies, a panoply of birds and wild bees that are native to New York City but threatened by what scientists have called an “insect apocalypse.”
Measures to help wildlife survive in, and migrate through, cities overlap with those needed to protect people from the impact of climate change and the related flooding.
Green roofs like the one in Greenpoint, for instance, are expected to multiply under a city law that is set to take effect next month and will require new buildings to be topped with green spaces or solar panels. Either measure can help reduce carbon emissions and rising temperatures; green roofs also reduce storm-water runoff. Currently, the 730 green roofs in New York cover just 60 of the city’s 40,000 rooftop acres, according to the Green Roof Researchers Alliance.
