In the concluding lecture of the series, Steve Cohen presents the definition and technical challenges of global sustainability. This includes: protecting ecosystems and biodiversity, preventing and adapting to climate change, reducing air and water pollution, ensuring a global food supply, developing land and handling waste, and finally, preventing human conflict. Cohen discusses the long-term and short-term financial issues for global sustainability as well as organization and management challenges, including issues of capacity, communication and coordination. He concludes by discussing the role of government and how existing policy instruments can deal with sustainability issues that cross international borders. Content in this video is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. http://creativecommons.org/licenses/by-nc-nd/3.0/