BY NATALIE LYNNE QUEALLY
I really love plants. They look good, quite often they taste good, and they’re pretty great at producing oxygen. It’s nice having them around, and I'm a huge proponent of putting more plants in the city. That's why one of my favorite trends cropping up in cities everywhere is the installation of green roofs. So what are they and what’s the big deal?
A green roof is pretty much what it sounds like—instead of being a flat, empty, hot space, the roof has vegetative cover instead. Besides looking fantastic, having green roofs in our cities has so many benefits I can’t believe they’re not everywhere.
First of all, there’s this thing called the “urban heat island effect.” Basically, all of our developed surfaces are drier and less permeable than natural landscapes, resulting in a temperature increase in cities as compared to neighboring rural areas. This effect necessitates higher energy usage for temperature control in buildings, which increases CO2 and other emissions from power plants. It also makes it just plain hot for us. That’s where green roofs come in. Installing one will reduce the temperature on the roof's surface, as well as inside the building, by absorbing heat and providing insulation, therefore lowering the energy bill.
But there’s more to them than just temperature regulation; green roofs provide many services for us and the other residents of our planet. They can reduce storm-water runoff through retaining and cleaning it, and improve air quality through intercepting airborne pollutants and filtering noxious gases. They also provide habitat for other organisms. With green roofs we have the chance to welcome birds, insects, and plants back into our cities.
Ultimately, these roofs are environmentally friendly, aesthetically pleasing, and versatile. There is no set type of green roof, so they can be as simple as a lawn or as complex as a mini park, complete with grasses, shrubs and trees. The Getty Center has a great example of a green roof well suited to the dry Los Angeles climate.
Although green roofs may have a higher cost upfront, they pay for themselves down the line—both economically and in ways that can’t be measured as easily. I think it’s time for us city-dwellers to mend our relationship with the environment, and this is a cool way to start.
Read about the urban heat island effect and mitigation here http://www.epa.gov/heatisland/mitigation/index.htm
Read about the function and benefit of green roofs here http://www.greenroofs.org
And for more inspiring examples of plants in cities around the world, check out http://urbangreens.tumblr.com