Not to mention that the sun has solar flares and activity that is causing Mars to have global warming and melt its ice caps. If Mars is warming up, and there is no life there to make CO2, then that means the sunlight is increasing. Which affects the greenhouse effect on Mars and Earth.

In Iceland I think they are experimenting with salts to counter the extra CO2 when mixed with ice and snow.

Global warming is the incorrect term to use, it is really climate change. Many global warming scientists have cherry picked the high temps and ignored the low temps. It seems that we are getting extreme hot and cold weather, and that these hot and cold fronts are clashing and causing the system of storms that we keep seeing like Katrina and the recent Mini-Ice Age in the USA that caused up to six inches of ice in some states. If you don't cherry pick just the hot temps and do all of the temps you get to see a pattern that goes up and down. Since it was not a true random sample, it was not statistically sound, and thus not scientific. Besides one needs a control group to follow the scientific method and since one cannot control the weather or temps, one cannot follow the scientific method for weather and temperatures. You need an experiment group and a control group, without those, it is just pseudo-science.

People forget about that hole in the ozone layer as well, and cries of global cooling in the 1970's.

Climate change is the correct term, and it gets hot and cold in extreme cycles. We can either fry or freeze as a result.