The Manhattan skyline is unmistakable. And it's a fan favorite—search Google "best skylines" and it will consistently be ranked in the top favorites. It has become a symbol of the city itself—sold on coffee mugs, in snow globes, on t-shirts. But what if the straight edges of the buildings and roofs were softened? If the roofs didn't pierce the sky but melded urban and natural a bit more easily? Imagine a skyline that could shift seasonally, and not simply as a result of new construction. It would be a subtler change that might confer a more real sense of the vitality of the cityscape. The icing on the cake? It would be good for us too.
Our recent discussion about infrastructure is definitely very much on my mind—particularly as my commute has now become longer and more congested as a result of shortsighted planning. The fire at the switching station on the LIRR has been a reminder of the vulnerabilities that lurk below the surface of our constructions. And provocations, stress on the system, can come from anywhere, including nature—something that New York City already knows: A thunderstorm on August 8, 2007 caused 7,000 kilograms (about 15,000 pounds) of dirt and debris to flood the subway system during the morning rush hour forcing New Yorkers and city officials to acknowledge that our subway drainage system is ill equipped to handle suddenly water surges. But this should not have come as news to anyone—we've been through this at least once before in recent memory: Lower Manhattan was flooded in December 1992 as a result of a storm.
Nature seems to be our biggest threat at the moment, and it's time we started planning and building with this in mind. A article from Scientific American earlier this year, reports the ways poor infrastructure can compound the effects of climate change. For example, a rise in temperature means it will get hotter underground as well. New Yorkers, you think it's hot in the subway during the summer months now? A 2 - 4 degree increase (predicted by 2100) may not sound like much, but you'll likely feel differently as the sweat pools at the base of your spine. One solution would be more vents to help push the hot air out of the subway, but more vents means that more water can get it—so we're back to dealing with flooding.
But it's not just planning below ground. What we choose to do with our open space is also an issue. We construct buildings. Fine. We all need places to live and work—I'm definitely not going to be the one to say we need to live in mud huts or caves or gather around an open campfire. But many of our buildings are capped off by black tar roofs. In the summer, they become infernos and add to the sweltering effect felt in the city.
One idea that is slowly gaining popularity is the suggestion that we can reclaim these spaces, these miniature hells, as National Geographic writer Verlyn Klinkenborg referred to them last August, saying that the urban roof is "a lifeless place of bituminous surfaces, violent temperature contrasts, bitter winds, and an antipathy to water." This doesn't need to be the case. But it will require changing the way we think about our landscapes—and our skylines. Green roofs reintroduce plants, supported by shale and clay to allow for drainage, and as an added bonus, they attract birds and insects, who may have been displaced by urban development. They can a more natural feeling to the concrete jungle.
Green roofs are not new ideas. They were common in sod houses on the prairies of western America, and apparently are still common in northern Europe. Urban architects are reviving the aesthetic in North America as they recognize the added benefits these features provide to urban planning overall: Green roofs can help regulate temperatures which could increase energy efficiency, and they help contain storm-water runoff which reduces sewage overflows, according to National Geographic:
On green roofs the soil mixture and vegetation act as insulation, and temperatures fluctuate only mildly—hardly more than they would in a park or garden—reducing heating and cooling costs in the buildings below them by as much as 20 percent.
When rain falls on a conventional roof, it sheets off the city's artificial cliffs and floods down its artificial canyons into storm drains—unabsorbed, unfiltered, and nearly undeterred. A living roof works the way a meadow does, absorbing water, filtering it, slowing it down, even storing some of it for later use. That ultimately helps reduce the threat of sewer overflows, extends the life of a city's drain system, and returns cleaner water to the surrounding watershed.
Cities like Chicago and Seattle have added a number of green roofs in recent years, but change has been a bit slower in Manhattan. It's a pricey endeavor, with costs averaging about $30.00/square foot for installation in the city, but I think there may also be an issue of vanity to contend with: The best surfaces for green roofs are buildings with large, flat tops well exposed to the sun. New York City's skyline has character—there are peaks and valleys throughout—so most of the green roof initiatives have been confined to the industrial areas in other boroughs. When Con Ed in nearby Long Island City unveiled their green roof, the New York Times began their feature by saying:
The thousands of recently planted green and purple shrublike sedum lining the roof of Con Edison’s training center in Long Island City look a bit out of place in the shadow of Manhattan’s skyline.
While there are opportunities in Manhattan for green roofs, most tend to lie just outside the borough's borders: Bronx County Courthouse (10,000 square feet), Ikea in Brooklyn (70,000 square feet), Ethical Culture Fieldston School (two roofs, measuring 5,100 square feet and 1,500 square feet, in the Bronx), and Hackensack Hospital in New Jersey (about 5,000 square feet). Developing more green roofs in Manhattan may require us to reconsider architectural plans going forward. And we may have to sacrifice some of our hard lines for softer ones. Because at the end of the day, questions of appearances and views aside, the economic and environmental impacts are hard to ignore. The largest green roof in Manhattan belongs to a postal facility on Ninth Ave, between West 29th and West 30th. The facility has reported over $1 million in energy savings to-date. Though it may be expensive to install, depending on the building's insulation green roofs can help keep buildings up to 30% cooler than black tar roofs, and the roof has double the lifespan. (Tax credits for building owners will probably also help usher in the change.)
These types of initiatives are exciting because they represent creative and meaningful ways of using space. If we can manage to implement more green roofs in New York City, we may also open the door for urban rooftop gardens, increasing the availability of local produce and reducing carbon footprints and food-prints. Granted, this isn't an overnight fix, nor will it magically undo the changes we have already wrought. Updating the subway system in New York City will take decades. But agencies like PlaNYC are looking ahead toward upgrades and conservation. The city has planted more than 322,000 trees as a part of its MillionTreesNYC initiative, and there are a fair number of hybrid vehicles in the taxi fleet (though the city has some work to do in converting the rest). The point is the awareness is there. And it's time to build intelligently. And to think about our relationship with the world around us and understand the long term effects of our decisions on not the just the landscape but on sustainability and our overall well-being.
Is your city in on the green roof movement? Or other green initiatives? Let's hear about 'em below.