The recent surge of interest in renewable energy and sustainable land use has made the airspace above land more valuable than ever before. Unfortunately, a growing number of policies aimed at promoting sustainability disregard landowners’ airspace rights in ways that can cause airspace to be underutilized. This Article analyzes several land use conflicts emerging in the context of renewable energy development by framing them as disputes over airspace. This Article suggests that incorporating options or liability rules into laws regulating airspace is a useful way to promote wind and solar energy while still respecting landowners’ existing airspace rights. If properly tailored, such policies can facilitate renewable energy development without compromising landowners’ incentives and capacities to make optimal use of the space above their lands. This Article also introduces a new abstract model to argue that policymakers should weigh the likely impacts on both rival and nonrival airspace uses when deciding whether to modify airspace restrictions to encourage sustainability.