Carbon dioxide (CO2) emissions from power plants and factories are among the biggest contributors to global warming. Efforts are underway to capture CO2 emissions from smokestacks and store them underground in perpetuity. At Stanford, researchers are exploring novel, low-cost ways to capture emissions on an industrial scale. The Stanford Center for Carbon Storage is studying techniques for storing CO2 permanently in underground reservoirs and mineral deposits, or using captured CO2 to make oil and gas extraction more efficient. Stanford researchers are also looking at the feasibility of net-negative technologies that remove more greenhouse gases than are released into the atmosphere. On the policy side, analysts are studying how a carbon tax or a carbon cap-and-trade system could spur implementation of CO2 capture and storage technologies.