I love your idea of planting trees. I think if I was rich, I'd start a charity with the purpose of turning the yards of those depending on government assistance and the elderly into food forests. Fill them with edible perennials and edible trees when there is room. Do it in a way that works with the land (and the neighbors trees) to provide a lifetime of food for those living in the house.

I'd also buy empty lots and turn them into food forests and let anyone who needs it gather food. It's all just a dream for now but someday...