CHEMISTRY BUFFS: If cars make CO (carbon MONoxide) how does (Can) it become...

[Dr. M]

...carbon DIoxide (CO2)? It would require a spare Oxygen atom - O1 or O - floating around at exhaustpipe level or near thereabouts and a chemical interaction (heat? electricity? static?) to make it take place (meaning, stay the heck away from tailpipes if it produces heat or causes static, and I don't see that happening to any degree or have I heard of it) or it would create heat or it would be an endothermic reaction which would LOWER the temperature..... And Oxygen doesn't float around as an O1 generally.

What gives?

Also, while I'm at it, in previous global warming episodes with rising CO2 levels, where did the CO2 come from if man wasn't around? And has it been PROVEN that CO2 CAUSES the earth to heat, or is it correlated and a byproduct OF the earth heating?

I'm just not getting this and nobody's explained it in any of the newspapers.

Cars make carbon MONoxide, diesel creates carbon DIoxide.

Plants thrive on CO2....just not getting it.....