Actually, if we go by NASA's GISS data (I know you love to pretend its a single guy you can then demonize), we have warmed .8 degrees in about 40 years. And the direct response to CO2 is only a fraction of the actual warming that will result....which has pretty much been validated by the fact that IT HAS WARMED THAT MUCH IN THE PAST 40 YEARS.
Thats just the air, of course. Most of that heat is being absorbed by the oceans, which will cause issues with ocean warming, climate changes, higher sea levels from thermal expansion, and massive disruption of an already stressed ecosystem.
So given that your numbers are off at the intial baseline, you're scratchy calculations are inherently dismissed by actual NON-AMATEUR scientists, who understand that the warming phenomenon by greenhouse gases is real, a problem, and potentially one that we have
underestimated.