The third possible cause is cause for concern:

"If the cloud-related albedo decline was caused not solely by internal variability, the 2023 extra heat may be here to stay and Earth’s climate sensitivity may be closer to the upper range of current estimates."

#ClimateSensitivity
#EarthAlbedo

https://arstechnica.com/science/2024/12/new-study-blames-recent-spike-in-global-warming-on-lack-of-low-clouds/