> They feel all accomplished and that they did their part. But if that doesn't have any real impact on the problem, then we've done lots of work, used up people's goodwill, but not dented the problem.

Does the evidence support that people's goodwill get "used up"?

It seems as plausible a theory to me that, when people get involved and take direct action, it ends up driving them to take further actions. Being personally invested in the result may drive more action rather than using up the goodwill.

(To be clear, I agree that we should always encourage action with the highest impact, and if tree planting actually does nothing to help solve the problem, then we should direct people to other activities. I'm not really jumping in to defend tree-planting initiatives, but more to question the assumption that people have a fixed amount of effort that they're willing to put into a given problem)