This Article argues that developed countries have an ethical responsibility to reduce energy consumption - through energy efficiency and conservation - as part of the global effort to reduce greenhouse gas emissions. While this responsibility is borne by nations themselves, it has consequences for the individuals living in those nations. This Article also argues that developing countries have different duties concerning energy consumption. Their responsibility to improve human quality of life will mean greater use of modern energy, especially when it is not now available. At the same time, developing countries should use energy efficiency and conservation when it is cost effective to do so.