This goes back to the reason why alarmists abandoned the "global warming" term in favor of climate change. They can play this bait and switch, showing changes in climate (which always exist) and then blaming them on CO2. But there is no mechanism ever proposed by anyone where CO2 can change the climate directly without going through the intermediate step of warming. If climate is changing but we are not seeing warming, then the change can't be due to CO2.