Computing has many potential “green” applications including improving energy conservation, enhancing energy management, reducing carbon emissions in many sectors, improving environmental protection (including mitigation and adaptation to climate change), and increasing awareness of environmental challenges and responses. An ad hoc committee would plan and conduct a public workshop to survey sustainability challenges, current research initiatives, results from previously-held topical workshops, and related industry and government development efforts in these areas. The workshop would feature invited presentations and discussions that explore research themes and specific research opportunities that could advance sustainability objectives and also result in advances in computer science and consider research modalities, with a focus on applicable computational techniques and long-term research that might be supported by the National Science Foundation, and with an emphasis on problem- or user-driven research. A report of the workshop will be issued.   In phase 2, the committee would obtain additional inputs through briefings to the committee and solicitations of comments and whitepapers from the research community. It would use additional deliberative meetings of the committee to develop a consensus report identifying promising research opportunities, cataloging applicable computational techniques, laying out an overall framework for “green” computing research, and recommending long-term research objectives and directions.