This relatively large increase is explained by the increase in temperature since the SAR was completed, improved methods of analysis and the fact that the SAR decided not update the value in the First Assessment Report, despite
slight additional warming.
Not exact matches
Here are some
additional linear regressions for some of the oldest data sets in the world - all show the same
slight warming trend over centuries and climate variability.
So what I'm getting is:
additional solar absorption is negligible (but exists), GHGs reabsorb heat in the IR bandwith radiated from the earth causing a
slight warming because it takes longer to reach an equilibrium.