This letter is from 141 actual, working climate scientists. It is an open letter written to the Secretary General of the UN.
It neither confirms nor denies anything. Rather the scientists ask the UN (and those demanding changes to taxing, spending and governance) to show observational data (un-manipulated) and accurate climate models (that actually show the changes in climate that we KNOW from recent history), to provide clear, unambiguous factual data proving both that something is happening and that it is the cause of man.
Both are reasonable requests. Should it turn out that something is, indeed, happening and that it is caused by human acticity, THEN there will be reason to go forward.
Even intelligent AGW proponents, i.e. those who look at science and are not treating this as a religious experience, will have difficulty in explaining why we should not ensure we have observable data on which to act — BEFORE we act.