Why is carbon dioxide a greenhouse gas?
Carbon dioxide (CO2) is a trace gas in Earth’s atmosphere and a member of the family of “greenhouse gases.” These gases, led by water vapor, receive their name because they help insulate the surface of the planet from the cold vacuum of outer space, enabling the existence of the planetary biosphere itself. CO2, like the other members of the group, qualifies as a greenhouse gas because of the way in which it absorbs infrared radiation and keeps it in the atmosphere.
