This article revisits a principle of distributive justice accepted by most, if not all, scholars of climate justice. The principle at stake, the limit, protects those who are very badly off from bearing the costs of climate change mitigation. The persistent noncompliance of developed states with their obligations toward burden sharing, however, means that this principle is increasingly in tension with successful climate change mitigation, given it seems to require that those in poverty have continued access to emissions in cases where alternative forms of energy are not provided. In the first half of the paper I outline this tension and show how the dominant expression of the limit in the literature, advanced by Henry Shue, must be abandoned. I argue that any attempt to articulate the limit in current circumstance, where the carbon budget is very scarce, must consider the climate harm associated with continued subsistence emissions. The second half of the article defends a principle, the exemption, which is best able to maintain the strong commitment to shielding those below the minimal threshold from the costs of mitigation, even in light of the potential harm that will result if they require emissions to fuel their energy needs.