It really isn't. You'd do well to try and claim that people without degrees in structural engineering are fit to design bridges, or that doctors who never went to medical school are okay to be surgeons.
In the same way, something as insanely complex as climate science needs a level of understanding that only a PhD can recognise. To claim otherwise is totally ignorant, but I suppose a little popularist.
Finally, 9000 is quite a minority. Numbers are meaningless without context. It's a long way to the sun, but thats nothing to the centre of the milky way.