Global Temperatures are Declining, CO2 Levels are Increasing. Does the "GW" Theory need to be Rethought?

It seems that what little I've learned is the Earth atmosphere has changed significantly many many times.With man or without the change has occurred so why is it totally what we've done. I believe we have affected this but its been a combination of the natural rotation of temp /atmo and our pollutants. Sunspots and other natural non-man related things are responsible also JMHO