By my count, there are four leading scientific explanations for the short-term slowdown overlaying the long-term rate of global surface warming. They are:
Enhanced heat uptake by the world’s oceans, especially over the Pacific due to enhanced easterly winds
Sustained small to medium-sized equatorial volcanic activity
Slightly reduced solar irradiance
Natural variability, including the Interdecadal Pacific Oscillation
One interesting aspect to these explanations’ presence is most researchers believe their explanation is the leading one. It is a symptom of the state of climate science: specialization proliferation leads to poor cross-disciplinary communication. Someone might have this within their purview, but I am currently unaware whether anyone is apportioning relative causality of these explanations together. Attribution is challenging, of course, but such an effort seems worthwhile to me.
Some recent science updates on these explanations: