This lecture explores the concept of green growth and the double-externality problem, focusing on the limitations of GDP as a measure of economic success. It delves into the challenges of measuring externalities, such as pollution and resource depletion, and the need for full internalization of costs. The instructor discusses the importance of innovation in responding to new cost signals and the role of the public sector in supporting the transition towards sustainable development. Various case studies and strategic papers are analyzed to illustrate the complexities of addressing environmental and societal issues while promoting economic growth.