The National Science Foundation's Environmental Sustainability program is seeking grant proposals that promote sustainable engineered systems compatible with maintaining natural environments and ecological services. The program supports research in four core areas: industrial ecology, green engineering, ecological engineering, and earth systems engineering. Proposals should be driven by engineering principles, involve graduate and undergraduate students, and may incorporate aspects of social, behavioral, and economic sciences. Innovative proposals outside the scope of the four core areas may also be considered. The program encourages Faculty Early Career Development (CAREER) program proposals, as well as proposals for conferences, workshops, and supplements. Compliance with the Proposal and Award Policies and Procedures Guide (PAPPG) is required. The typical award size for the program is around $100,000 per year, with a duration of one to three years. Proposals requesting substantially higher amounts without prior consultation with the Program Director may be returned without review. Research projects that demonstrate the potential benefit to the United States, even if conducted outside the country, will be considered.