>> There’s a charitable organization here in San Francisco that plants trees throughout the city for the benefit of all. If one of their tree’s shade falls on a cafe table and cools the cafe’s patrons as they enjoy their espressos, does that mean the tree-planting organization is no longer a charity?
In fact, the tree-planting group can easily show that they serve an exempt purpose, namely "lessening the burdens of government". Planting trees is something that city governments routinely do for the purposes of beautification or whatever. If a non-profit wants to do it, that's a perfectly legitimate reason to get tax exempt status. The group would also have to show that they are serving a public interest - for instance they're not just planting trees outside of one company's coffee shops but they're providing a service for the whole neighborhood.