
I've been a fan of the United States Postal Service for a very long time. Perhaps it's the architecture: those classic columns you see on so many Post Office buildings here in New York (I've always thought the magnificent columns at the General Post Office at 34th and 8th to be sheer poetry in concrete); those historic or quaint buildings you see out of town.
Perhaps it's the amazing amount of mail that circulates through the system (if I recall correctly, it's something like a million pieces a day at the sorting facility in New York City, with 2.5 million during the holiday season), with so little of it going astray or getting chewed up.
Or perhaps it's the invariably dramatic, democratic-people's-republic feel of standing on the inevitable line with my neighbors, good and bad, rich and poor, grumpy and congenial, an event that always reminds me of
The Line, the play by Israel Horovitz.
You just have to try sending something to the Central African Republic (don't! -- give it instead to someone you know and trust to deliver) to really appreciate our venerable, home-grown institution, even though it has fallen out of favor in the high-speed Internet age and is short on money.
So I was disposed from the outset to have a great time getting a tour of the new green roof at the P.O sorting facility on 30th and 9th, sponsored by the Science Writers in New York (SWINY). But, as has come to be usual for me with SWINY-sponsored events, reality trumped my imagination once again.
The green roof at the P.O facility is currently the largest in New York and is a sublime, peaceful oasis of a place. A huge number and variety of hardy, colorful, low-lying plants, suited to hot summers, cold winters and arid conditions, fill enormous, densely packed, 4-inch high, metal-sided containers, in an area large enough that it takes several minutes to traverse its entirety along the meandering walkways.
For this event, the guides were
Stuart Gaffin, a climatologist from Columbia University's Earth Institute, and a representative (whose name I didn’t catch) from the company who installed the roof:
Tecta America.
From them I learned that the 4-inch thick green roof is capable of reducing roof rainwater runoff -- and its contribution to the overload of the city's sewage systems and pollution of the river -- by half, and cooling the roof from 170 degrees Fahrenheit or more on a black roof, to the much more tolerable ambient air temperature.
Due to the building's insulation, the direct cooling effect of the roof on the air inside the building is minimal, but the reduced temperature of the air processed by the building's air handlers does have a measurable and significant impact.
Because the plants absorb water and regulate temperature extremes through
evapotranspiration, a green roof also protects the roof from weathering, potentially increasing the longevity of the structure by decades; and green roofs increase the biodiversity of the city, offering sorely needed habitat for butterflies and other beneficial insects.
Although white roofs are currently favored over green roofs because they are cheaper and quicker to implement, and have the potential to rapidly diminish the "heat-island" effect of a large city like New York, the only (although critical) environmental benefit white roofs offer is reduced temperatures, and since they quickly become grimy, keeping them white is an additional expense.
I think
white roofs are essential as a short-term solution to reducing the city's substantial carbon footprint and effect on local air temperatures, but I agree with Dr. Gaffin that the superior environmental and structural benefits of green roofs should prove them to be the more cost efficient in the long term.
Because of security measures, I could not linger after the presentation, but the beauty of the waning light, the pleasant breeze off the Hudson River and the soothing presence of all those lush living plants were so enticing that I departed with reluctance.
Click here to see the video: Green Roofs: Ingenuity Sprouting from the Rooftops.