Water vapor averages about 0.4% of the atmosphere, CO2 0.039%. So CO2 is about 10% of the atmosphere responsible for the greenhouse effect. Water vapor lasts a very short period of time in the atmosphere (less than a month), so it can’t drive climate disruption – it can only be a feedback term, not a forcing term. The next most common greenhouse gas is CO2, and it lasts in the atmosphere for centuries once released. So it is a forcing term (although it’s also a centuries-long feedback as well).

As for your claim that humans add 0.7% of CO2 to the atmosphere, this is also an insufficient explanation. Natural CO2 is largely in balance in the global ecosystem with geologic weathering, ecological uptake and conversion to biomatter, and absorption into the ocean. CO2 emitted by man is stuff that was sequestered underground for millions, perhaps billions, of years. And since pre-industrial days, human-emitted CO2 has increased the overall amount of CO2 from 0.028% to 0.039%, an increase of about 1.4x the baseline. Furthermore, isotopic analysis of the CO2 in the atmosphere points incontrovertibly to human origins rather than geologic origins (volcanoes).

Your comment from the CRU emails neglects to mention that the comment was made in response to ocean warming and in a context of bemoaning the lack of sufficient spatial and temporal resolution in the ocean heat monitoring sensor network.

And finally, I’ve addressed the CO2 vs. flat temps over the last 10 years repeatedly in other comments.