At 415 ppm CO2, there is now more CO2 in the atmosphere than since humans came to exist, and since the Pliocene Epoch about 3 million years ago, where global temps were 2-3º C warmer than they are now.
During the Pliocene there were trees in the arctic and global sea levels were 25 metres higher.
The thermal inertia of the oceans means that it takes somewhere around 40 years for the full effect of CO2 increases to be felt by the planet. So the approximate 1ºC of warming the planet is experiencing now is from the CO2 put into the atmosphere in the '70's.