Carbon dioxide cause the earth's average air temperature to increase.
Higher temperatures cause particles in the earth's atmosphere to move faster.
This creates more energy in the earth's atmosphere. The energy causes air and water to move around the planet. The result can be as simple as a slight breeze or as complex as the formation of a hurricane. The greater the amount of energy in the atmosphere, the more severe the weather. There is evidence of increased energy in the atmosphere over the United States, where the occurrence of severe weather has been increasing over the past century.