Carbon capture and storage aims to prevent CO2 emissions from large stationary sources like power plants from entering the atmosphere. It involves capturing about 90% of CO2 emissions, compressing and transporting it, then permanently storing it underground. CO2 can be stored in deep saline formations or depleted oil and gas fields, where it becomes trapped between rock grains and in the pores of reservoir rocks. Several CCS projects have already stored millions of tons of CO2 underground for decades. While CCS could help slow the rise of atmospheric CO2, it is still a relatively new technology that requires further development and legal/regulatory frameworks to become widely implemented.