I wish I saved the emails from 2003 when I was corresponding with James Hansen and he told me that his calculations proved beyond a doubt that man's influence had overtaken the sun's influence as the primary driver of the climate!
CO2 is small but nonzero in its warming coefficient as applied to the equations. As any modeler should know, the entire point of a model is to replicate reality, and if it doesnt, then one's model needs fixing.
CO2 simply does not have the power to drive climatic outliers. These come from the sun.
The sun is at the center of the solar system - but not at the very gravitational center. It actually dances about this point, and part of what modulates its wobble around the barycenter (that's the gravitational center) is the motion of the large planets. The motion of the large planets actually has an additional effect of modulating the solar tides on the sun - this is what's responsible for the variation in the 11/22 year sunspot cycle.
When the large planets gang up, they advance the tides, there are more sunspots - and like in the early 2000s, measurements in the upper troposphere showed that the Earth's atmosphere grows when the sunspots create those conditions. Sunspots are concentrations of magnetic flux that are indicative of the deeper solar process that generates them.
When the motion of the larger planets decoheres, this "puts less squeeze" on those processes, and sunspots disappear when the flux is not dense enough to crowd out the solar filaments.
The Earth's atmosphere reacted accordingly the last time this happened. See 2009's 280somethin spotless days on the sun.
And then over '10-11-12-13, everyone went "holy shit, look at that polar vortex" as the slight collapse in the upper atmisphere gave way to the enhanced vortex, which kept a lot of the cool temps isolated - but then, losing momentum, the vortex wobbled (we saw batshit cold in USA/warm russia, then batshit cold russia, warm USA) and then decohered.
What I just described is exponentially greater in effect than CO2 could ever hope to be, and not having any really decent model of solar processes, combined with that shitty bastard halfass TSI, it becomes the case that their impotent models, containing no predictive capability whatsoever, could not have possibly seen this coming.