A common misconception is that the climate sensitivity and temperature change in response to increasing CO2 differs from the sensitivity to
other radiative forcings, such as a change in solar irradiance.
Thus we have often made the point that diagnosing this imbalance through measurements of temperature in the ocean is a key metric in evaluating the response of the system to changes in CO2 and
the other radiative forcings (see here).
However, estimates of the planetary climate sensitivity to increasing atmospheric CO2 and
other radiative forcings are not solely based on the change in the mean global temperature over the past 100 years.
If you're wondering why CO2 dominates the political and policy discourse, this has something to do with the long lifetime of the CO2 forcing relative to
the other radiative forcings.
Radiative forcing as a result of increases in atmospheric CO2 concentrations caused by human activities since the preindustrial era predominates over
all other radiative forcing agents (IPCC, 2007a, SPM).