Scientists haven't pinned down exactly how much temperatures rise per doubling of carbon dioxide — known as the climate sensitivity. (carbonbrief.org)
Computer models of these past climates suggest that the long term climate sensitivity is at the high end of current estimates, in the range 4 to 5 °C per doubling of carbon dioxide in the atmosphere. (thiniceclimate.org)
A convenient yardstick to measure how sensitive the climate system is to increases in the concentration of greenhouse gases is the equilibrium climate sensitivity (ECS)-- the surface warming eventually reached after a sustained doubling of carbon dioxide concentrations. (climate-dynamics.org)