03.14.07
Zone Roof Gardens to Plan For Abrupt Climate Change (the game)
If you knew global warming would bring an abrupt climate change, roof gardens might be close to a first response. (See premise for the game.) Better yet, they offer immediate benefits.
Roof gardens are of two types. There are shallow gardens that use between 1 to 4 inches of dirt and are relatively low maintenance called extensive roof gardens. There are also intensive roof gardens that are often landscaped retreats that have at least 8 inches of soil, irrigation systems and can require significant roof reinforcement. Both offer immediate benefits of extended roof life, energy conservation, runoff control, air pollution mitigation, and ambient air temperature reduction in urban areas.
If you were only concerned with peak storm runoffs, global warming or energy conservation you might start zoning to encourage moving towards all roofs having extensive roof gardens. If you know you need to be able to maximize food production, you might start tax breaks for intensive garden roofs. Growing your food on your roof not only greatly increases the fertile area that may be available to some communities, it may provide added security for crops in the scenario postulated by the community planners game.
This is long-range strategy that could take 40 – 50 years to become fully functional. Even with great tax incentives (even more hypothetical than abrupt climate change) roofs will primarily be replaced as they wear out or as new homes are built. If new homes are built now with extensive roofs, it is expected that it will be 40 years before they require a new roof.
