Other IPCC consensus "experts" are wildly throwing around a hodgepodge of reasons that at last count was up to eight. Take your pick.
One reason definitely not on the table for discussion by climate reality deniers resisters is the obvious one: increasing CO2 levels are having little impact on global temperatures, which means that nature's normal climate forces overwhelm any CO2 influence. For the consensus scientists to open this can-of-worms would be the death knell of the AGW hypothesis - scientists driven by greed and the limelight do not willingly eviscerate the golden ox that has produced multi-billions for research grants and scientific studies.
Yet, when scientists examine the empirical temperature measurement datasets, it becomes readily apparent that changes in CO2 levels are not generating the expected changes in global temperatures, as predicted by the immensely powerful and sophisticated (and incredibly costly) climate models.
This obvious climate reality is portrayed in the above chart. Literally, 3-year changes in CO2 levels have no correlation with 3-year changes in global temperatures for the IPCC's modern era, starting with 1950. Simply put, one does not have to be a rocket scientist, nor a climate scientist, to ascertain that the CO2-centric AGW hypothesis is severely dysfunctional.
Eventually, global warming phase will return, as it always has in the past, but the climate models' prediction outcomes (and credibility) will likely be even worse, if that is even possible.