The Twenty-Seventh AAAI Conference on Artificial Intelligence (AAAI-13) convenes next week in Bellevue, Washington USA. For the third consecutive year there will be a special track on Computational Sustainability, a nascent and growing field of computing that is concerned with the application of computer science principles, methods, and tools to problems of environmental and societal sustainability. This is not a one-way street, however, because sustainability problems force computer scientists into new theory, as well as new practice. For example, sustainability problems require extraordinary attention to solution robustness (e.g., so that a so-called optimal solution doesn’t catastrophically fail with an environmental change) and issues of uncertainty, ranging from uncertainties in environmental sensor readings to uncertainties in the budget awarded by a state legislative body for wildlife management!The 16 papers of the Computational Sustainability (CompSust) track of AAAI (http://www.aaai.org/