People that think humans cause Global warming*.................?

How do you explain, the Ice Ages, and big chills that the Earth has experienced oh I don't know that lat 4.5 BILLION years? There have also been hot points, where th Earth " thaws out" from the ice ages, and warms up, then cools off. That's our planet. Humans have been emitting pollutes in the earth's atmosphere for like 130 years, at the most. Do you know how many comets and asteroids have slammed into this planet? Don't you think that would have a bigger effect on the Planet than Driving down the street, or burning coal?