Are you actually saying that just because some people tell really scary stories that we should beleive them? I don't think so. They contradict themselves constantly. Every few years "most of them" have a different story to tell.
Over a twenty year span they've gone from a big temperature drop to a big temperature rise to a rise that maybe isn't not so much. Why should I take "them" seriously? I mean it's certainly not wise to rely absolutely on just one man that contests the results found by the whole community.
You say that it's not wise to rely on just one man. Well, shoot, this one man is simply protesting about the whole situation around Yellowstone.
The "whole community" is decidedly not in agreement. Ecofreaks and Big Media like to make a big deal about how thousands of scientists have signed this or that to say that they are worried about climate change. Well, when the names are checked out, most of the people who signed these pieces are not climat specialists and many of them are not even researchers at all. It's also not at all true that the whole community of clime specialists agree on the subject of global warming. In fact, a little less than half of the actual researchers even agree that there may be a problem. Less than that agree that humanity has anything to do with it.