Which statement is true regarding the gas carbon dioxide?
Review of the options:
Carbon dioxide is an unnatural gas that is only formed during the burning of fossil fuels. – False, carbon dioxide is also formed during the burning of wood, for example.
Carbon dioxide contributes to the greenhouse effect. – True, carbon dioxide is a greenhouse gas, see the pictures below.
Carbon dioxide has been a major problem in the past, but the catalytic converters in new cars filter out all carbon dioxide. – False, the catalytic converter’s major problem is that it cannot convert carbon dioxide.
Carbon dioxide is the only substance that an effective catalytic converter emits. – False, the catalytic converter also emits other substances, mainly water.
Normal greenhouse effect
The rays of the sun (yellow arrows) pass through the atmosphere (grey line) and reach the earth. Much of the heat is absorbed (red dots) and the excess bounces off the earth’s surface and is reflected back out into space (red arrows).
Enhanced greenhouse effect
The car releases emissions into the atmosphere, which makes it thicker. When the atmosphere gets thicker, some of the heat rays reflected back from the surface cannot get through. These rays instead bounce back towards the earth while emitting more heat. In other words, the earth is getting warmer than it otherwise would.