Although considered critical to avoiding catastrophic global warming, the feasibility of removing carbon dioxide from the atmosphere and storing it underground has been in question. Because plants naturally absorb CO2, they would be an obvious way of sequestering CO2 from the atmosphere. Ethanol production is the easiest way to convert plants to fuel and capture the CO2. An estimated 60 percent of all annual CO2 emissions through ehtnaol production at the USA's 216 biofuel plants (about 1 percent of all CO2 emissions from the U.S.) could be captured at low cost. Tax incentives seem the best way forward.