Last fall I taught a class on climate change and urban development which focused on climate change impacts and adaptation in urban settings. Emphasis on urban agriculture was among the various adaptation practices employed to mitigate the impacts of climate change and assure food security. Urban agriculture entails the growing of food in an urban setting. This may include community gardening plots on open lots, rooftop gardens, and/or gardening in any available open space within cities.
Our visit at Up Top Acres during the Northern Virginia/Washington DC seminar gave us a closer look at urban agriculture in the form of rooftop gardening. Rooftop gardening has several important socio-economic and environmental benefits. The production of fresh fruits and vegetables closer to the consumption source is economically, socially, and environmentally advantageous. Rooftop gardens not only makes use of an otherwise underutilize rooftop space but also ensures easier access to fresh food by inner-city residents. According to Roof Top Acres, the rooftops are usually provided to them free of charge and some of the food grown is sold to the residents of these buildings.
On the environmental side, rooftop gardens reduce energy costs in terms of transportation and refrigeration required to ship food from long distances or rural areas. Additionally, it helps with the cooling of the buildings which also reduces energy consumption. Combined with rainfall harvesting, rooftop gardens can reduce groundwater depletion. Rooftop gardens can also serve as sanctuaries for urban wildlife thereby contributing to biodiversity within cities.
An important challenge is that older buildings are often not conducive to rooftop gardening. For example, the layout of roofs coupled with the weight capacity may threaten the structural integrity of the building. While some buildings can be retrofitted to accommodate rooftop gardens, the costs often outweigh the benefits. However, newer buildings are incorporating rooftop gardens as part of the Leadership in Energy and Environmental Design (LEED) certification.
In a time of unprecedented climate change and concerns about food security, rooftop gardens are economically viable, socially equitable, and environmentally responsible.