Climate change is real and has been happening for millennia.  It was happening before humans appeared and will continue to occur after we go extinct.  The GTA was under a mile of ice, thousands of years ago, and so it will be again some day.  Only a fool denies it and only a fool believes there's any definitive proof it's caused by anthropomorphic CO2 emissions.  A volcano belches and lets out more CO2 than we have since the beginning of humanity.  CO2 promotes the growth of vegetation, which then sucks in CO2 and gives off oxygen.  Protect the forests and we'll all be fine.