I posed the question earlier about why reality wins at wikipedia, the encyclopedia that anyone can edit, when it's a closer call for dealing with everyone in general. Imposing the question later at Stoat got an answer from William, better than what I'd suggested:
if there is a conflict, you’re required to talk, on the talk page, to resolve the issue. If you’re not able to talk sanely, you’re going to lose when others come to see the debate, or when the admins come to visit. I think that is the crucial piece -WSounds right, although it also takes us to the next question - why do these admins, who aren't especially focused on climate science, decide that reality is sane and the denialists not? I'll give myself a consolation prize here, that wiki's emphasis on Reliable Sources and high education levels among editors and admins both push somewhat in favor of reality.
William also makes another point about the cost of it all:
I think that the wiki-bureaucracy tends to see the end result – mostly decent pages, e.g. Global Warming – and fails to appreciate how much the energy drain and inevitable disrespect puts people off -WIt takes a lot of effort to fight nonsense. I personally got tired of it after a while and have done mostly innocuous wiki edits in recent years. Might finally get back in though - I think wiki might need an article on stratospheric cooling. Anyway, it's interesting that wiki got things right, mostly, many years before the mainstream media.
Related thought - hard to overstate wiki's importance as a source of information, so another interesting question would be to what extent scientific reality has gained a foothold among the public, especially the young, because wiki is a fairly accurate source that excludes denialism.