Susuto

think123 - Yes the effect of CO2 is logarithmic. 2 points for you to consider, CO2 is just one of many greenhouse gasses, methane for example has a much, much greater effect (23 times greater) - CO2 equivalent is often used as it is the most abundant and people seem to have latched onto CO2 instead of using a generic term. The second is that the rate at which we increase our output of GHGs is not just increasing linearly, the rising economies of the world are growing and are increasing outputs exponentially.
The sun - of course the sun is the primary driver of climate change in the past. The rate of change of temperature in recent history however does not match up with the suns output. You honestly don’t think that the scientists working on this have not considered these most basic facts????