Department of Energy Researches Carbon Sequestration
The Wikipedia entry on carbon sequestration explains:
Carbon sequestration is 'The process of removing carbon from the atmosphere and depositing it in a reservoir.' It is a geoengineering technique for long-term storage of carbon dioxide or other forms of carbon to mitigate/defer global warming. It has been proposed as a way to slow the atmospheric and marine accumulation of greenhouse gases, which are released by burning fossil fuels.