When it comes to global warming and the regeneration of land, trees have enormous value. Yet, short-term challenges force many people in the developing world to cut down trees. Would it work to pay landowners to leave their land alone? Critics have argued that such a policy would simply make the landowners shift their land use to places not covered by the payments. However, a two-year study in Uganda shows that tree cover declined by about half as much in villages where payments were offered compared to the villages where they weren’t, and it found no evidence that landowners who were paid to preserve their land shifted their deforestation to nearby land.