global warming and water vapour, page-8

No one denies the effect of water vapour as a greenhouse gas. In fact here has been a fair bit of research conducted on water vapour and it's interactions with other greenhouse gasses. Most notably, the feedback associate with CO2.

http://maths.ucd.ie/met/msc/ClimSyn/heldsode00.pdf

Here's a quote from his profile at The Earth Institute:

"Broecker and Lackner are leaders in the war on anthropogenic climate change and both advocate drastic changes in people�s carbon emissions and the dire need for large-scale carbon sequestration."

Now, why would one of the leading experts on atmospheric water vapour be so concerned about CO2 emissions, if it had no effect on our climate?