What We Really Need is More Trees
I have previously sung the praises of tree-planting in this space, so consider the post a "PS" on that. The print version of this article from American City and County about a tree-planting program in Pittsburgh has a picture of a new tree with a remarkable tag on it that reads: "In its lifetime, this tree will 'pay us back' an estimated $3,136.80 in energy conserved, higher property values, stormwater intercepted, and cleaner air."
Leave aside the impossible precision of that dollar figure, or the fact that higher property values ARE the capitalization of the other three advantages, so there's probably some double-counting in there. But whatever the number is, it's likely far more than the cost of planting the tree in the first place.
I know our cities have a lot of things to worry about now, what with rising crime and widening budgets and soaring pensions and crumbling schools. But hopefully we can also figure out ways to get some more trees planted. We could all use the return on those investments.