What I disagree is how you jump from point A to point B to point C when there's no evidence that A is causing B which is causing C.
The first points are observations. Satellites we put into orbit show a net energy gain for the planet. If you don't believe this then you must have issues with how the data is being gathered/interpreted. Otherwise this is first year thermodynamics. When energy in is greater than energy out temperature rises until equilibrium is reached.
If there were more energy coming from the sun that would explain the observation. It's not, we can measure the output.
So the Earth is retaining more of the energy that reaches it.
From there it's looking at the various hypothesis as to why more energy is being retained. C02 is a prime candidate as it causes a retention of energy.
This has been tested in labs to prove that CO2 traps heat more so that other gases released into the atmosphere.
We can measure the increase in CO2 in the atmosphere. We know roughly how many barrels of oil and tons of coal are burned in a year. We know that the CO2 released from these activities has not been present in the atmosphere for millions of years.
There are similar issues with methane and water vapor.