In order to achieve sustainable development, a good understanding of the interactions between economic, social and environmental factors is critical. In a Development Policy Seminar organized by DPAD, Dr. John Shilling of the Millennium Institute presented the Threshold 21 Model, a systemic approach to understanding these interactions and feedback loops. Scenario analysis based on the Threshold 21 model can be used to better understand the economic, social and environmental impacts of changing food consumption patterns, which is of interest for the Division's work on the post-2015 development agenda.