You have to prove that increases in CO2 cause global warming.
No I don't. But I do have a little experiment I tried. And you can try it to.
Back your car up to your house and connect a hose from the tail pipe to your house window. Seal everyting up real tight. Hopefully you filled your gas tank up. Start the car and let it sit and idle till the gas runs out.
Then go in your house (do not stay there) and see if the climate inside your house changed for the worse or the better. Did the temp increase. Did the concentration of CO2 gases increase. What other changes occured. Were they for the better.
After you conduct this little experiment (which is real fun) we can compare results.