The only outside source of energy is the sun.
The only other source of energy is orbital/rotational friction, which has to be very small, by comparison.
The effects of volcanic erruptions are short; rarely last longer than 8 months, while sunspot cycles are 11-17 years.
The current lag in sunspots has measurably reduced IR, while allowing an increase in UV due to the reduction of water vapor from the reduced IR. This isn’t new.
Irregardless is not a word in our language.
Citation? My references indicate that satellite data show an increase in atmospheric water vapor.
So sue me for not using a word in "general acceptance".