What is the most effective thing an individual can do about climate change? There are lots of possible answers: what you eat, how you vote, where and how you live, how you travel, and so on. Every one of them matters. For Americans, at this moment, the one that matters most may be how you vote.But among the steps most immediately within many people’s control, one of them is planting trees. Yes, there are cautions about doing this in the wrong way, or in the wrong places, or in ignoring the legacies of long-standing biases in zoning and city planning.