The atmosphere has become less polluted over time.

It is false that the atmosphere has become less polluted over time. 

This statement is false. It is because throughout the years, the atmosphere becomes more polluted. The main cause of air pollution is carbon monoxide. Most carbon monoxide emissions come from motor vehicles. This affects our health and environment. Air pollution causes millions of death per year.

B) raising the temperature and reducing the volume of the gas.|-/