Dr. Leif Svalgaard, Solar Scientist, Stanford University:
In my view some, X, of the climate change is due to CO2, some, Y, is due to the Sun, and some, Z, is due to internal, random fluctuations. The only question is how much of each. Perhaps it is X=10, Y=10, and Z=80 [they may even vary with time].
M..A.Vukcevic independent researcher:
Where Z is due to the Earth's internal (oceans to the core) fluctuations. These natural fluctuations (whatever mechanism/s) are reflected in the changes of the geomagnetic field and therefore easy to measure.
CO2 ~10%, TSI ~10%, Earth's internal ~ 80%
Earth has a magnetic 'ripple' originating in the core and the sun has its cycles.