1. Climate Sensitivity to atmospheric CO2 concentration is a very wide range due to uncertainty in understanding and arguments between various modellers over how GHG works with feedback both positive and negative.
AR5 Says: Equilibrium climate sensitivity is in the range
a. likely 1.5 °C to 4.5 °C (high confidence),
b. unlikely less than 1 °C (high confidence), and
c. unlikely greater than 6 °C (medium confidence).
i.e. The range of possibilities is from less than 1 degrees C to greater than 6 degrees C per doubling of CO2 and they even have a broad range of 1.5 to 4.5 in the likely category.
And on the basis of that distribution of possible outcomes you say a future ice age has been averted with certainty........I disagree with your binary outcome and suggest it is not certain.
2. If warming is less than 4.5 degrees C per doubling of CO2 (AR5 likely scenario) then at current rate of increase of 2 PPM per annum it will take 200 years to warm 2 degrees C and we can adapt. CO2 was > 5000 PPM 500 million years ago and life flourished (look up the Cambrian Explosion). The seas were warm and there were no polar ice caps. Surely that is a better world than an ice covered frozen tundra?