Climate change presents an unprecedented and existential threat. Proposals addressing this threat are criticized as impractical, costly, and/or beyond the legitimate scope of government power. We engage the latter critique by turning to John Locke's writings. Locke is both a proponent of limited government and profoundly influential on liberal democracies. He argues that government exists solely to enforce the natural law, and in doing so, protects life, liberty, and property. While Locke presents the Earth's resources as existing to be exploited, (...) he limits property acquisition, arguing that natural law prohibits spoilage and requires that we leave ample, quality resources for others to utilize. We argue that since these caveats are part of the natural law, government is obligated to take comprehensive action addressing climate change. (shrink)