I've seen this argument with slightly different numbers:
Water vapour was responsible for 95 per cent of the greenhouse effect, an effect which was vital to keep the world warm, he [meteorologist Augie Auer] explained.You would think so. And even if water vapor is 80%, it still dwarfs CO2. Maybe we're lucky though. If the blame shifts to water vapor, the zealots may start trying to restrict our water use.
"If we didn't have the greenhouse effect the planet would be at minus 18 deg C but because we do have the greenhouse effect it is plus 15 deg C, all the time."
The other greenhouse gases: carbon dioxide, methane, nitrogen dioxide, and various others including CFCs, contributed only five per cent of the effect, carbon dioxide being by far the greatest contributor at 3.6 per cent.
However, carbon dioxide as a result of man's activities was only 3.2 per cent of that, hence only 0.12 per cent of the greenhouse gases in total. Human-related methane, nitrogen dioxide and CFCs etc made similarly minuscule contributions to the effect: 0.066, 0.047 and 0.046 per cent respectively.
"That ought to be the end of the argument, there and then," he said