This paper definitely contained a lot more hard science than many of the other ones that we have read, especially when it came to discussing some of the biology and chemistry in the methods of pollutants being removed and the results of the dozens of experiments and studies being performed. There was even a whole section dedicated to explaining the criteria for the selection of articles to be used as references for the paper. Despite this, Rowe clearly demonstrated the many benefits of having green roofs, other than the most apparent one, which would probably be their aesthetic appeal resulting from lush, verdant vegetation covering up once-useless wood and shingles.
Green roofs reduce air, water, and noise pollution, mitigate the effects of the urban heat island, take up less space in landfills, release less carbon dioxide, and provide countless positive outcomes to many aspects of human health, especially physiological and psychological. One particular statistic that I found interesting was that “emissions from coal fired power plants could be reduced by 350 tons of NOx per day in Los Angeles by reducing the need for air conditioning…[this] results in a savings of one million dollars per day” (Rowe 2102). Los Angeles might have a much different climate than New York (mild, wet winters and bone-dry, warm to hot summers) and topography (with all of its valleys and mountains), but its metropolitan area has more than eighteen million people, so this proves that green roofs can be implemented on a large scale in some of the most populous urban conglomerations in the world.
Not surprisingly, green roofs are not foolproof and have a few drawbacks. It was mentioned that “particulate matter cleaned from the air that adhered to leaf surfaces will be washed off by rain and eventually leach into the stormwater system, thus trading air pollution for water pollution” (Rowe 2104). Furthermore, only the magnitude and frequency of precipitation, mostly rain, was discussed; what about snow, sleet, hail, ice, or other meteorological events, such as extremely hot or cold temperatures and wind? Lastly, it seems that green roofs will take a giant amount of time and effort to plan, ranging from engineers and architects discussing the design appropriate for the building to botanists selecting a certain group of species to other workers maintaining the green roof for years to come. Regardless, this idea looks extremely promising, and a cost-benefit analysis will likely allow green roofs to enter the mainstream if they have not done so already.
