I’ve often viewed agriculture, urban agriculture in particular, from a resource perspective. In order to grow food, people need access to land, water, genetic stock and knowledge. I’ve taken for granted one absolutely essential resource: energy from the sun. This is available to everyone, everywhere, right? (Of course, I’m ignoring the far north and far south polar regions, that lose sunshine for months at a time.) Turns out I am wrong. I need to include access to sunshine as one of the critical factors. (more…)