Abstract  Libertarian justice arguably permits much that is harsh. It might plausibly be thought to generate only minimal obligations on the part of present people toward future generations. This turns out not to be so, at least on Nozick's version of libertarian justice, which is among the most thoroughly worked-out versions. Nozickian justice generates extensive obligations to future people. This provides an indirect argument for environmentalist policies such as resource conservation and wilderness preservation. The basis for these obligations is Nozick's use of Locke's proviso, which is spelled out using the notion of the baseline. This paper explains how the extensive obligations are implied by the core ideas of Nozickian justice. There is also a discussion of some of the difficulties involved in understanding the notion of the baseline. However, these difficulties do not destroy the theoretical basis for obligations to future generations contained within Nozickian justice. Provided that libertarian justice involves some such device as Locke's proviso the enforcement of substantial environmentalist policies comes within the ambit of the libertarian minimal state.