A growing body of research predicts deep subsea rock formations may be ideal for carbon sequestration — the process of storing carbon dioxide emissions underground to keep them from entering the Earth's atmosphere and contributing to climate change. A number of researchers already are conducting projects to inject CO2 in onshore formations to see if large amounts of the greenhouse gas can be stored underground indefinitely. Daniel Schrag, a professor at Harvard University's Department of Earth and Planetary Sciences, says the high pressures and low temperatures found below the sea floor — 10,000 feet or more underwater — provide a nearly foolproof way to keep CO2 stored. In those conditions CO2 becomes a liquid more dense than water that will not rise up to the ocean floor. "It's a pretty simple idea that has much lower risks than carbon sequestration on land," Schrag said. "And there's truly a huge capacity for storage under the sea floor."