Throw in some solar panels too! I have no idea what the balance is, or which route is actually 'greener' in an environmentally-friendly sense, but definitely part of the experience of a green city for me would be to actually have it green-colored and covered in plants. But if you can grow a lot of your food right on top of the building, then at least that cuts down on the need to expend energy transporting it in. And between having lush greenery overhead and building open-air structures with natural ventilation, hopefully it would be cool enough to reduce the need for air conditioning. The building I live in has good natural ventilation and so I actually haven't had AC these four years and I've survived in the blazing Cambodia heat :)