"However, with 11,000 scientists backing a statement which tells of ‘untold suffering’ if we don’t act soon, there can be little doubt that climate change is influenced by human activity and should be taken seriously."

That's like 11,000 cattle ranchers signing a statement that says "Eat more hamburgers!" In the USA alone there are 6.9 MILLION scientists and engineers, so 11K is a tiny fraction of them. I'm going to guess that most of the scientists around the world have the humility and professional integrity to not sign something about a subject that they don't don't know anymore about than your average person. Scientists are not magical, and the vast majority of them are specialists in a very narrow field. But what if all of them are "climate scientists"? Climate science, which was only established in the 1970s with the advent of computers and satellites, has no reason to exist if AGW isn't true. What would they do without it?