Edinburgh Skeptics is very loosely part of a world-wide community which takes a science- and evidence-based approach to a variety of issues. You can find locally established Skeptics in the Pub groups putting on talks and events all over the world, and there are many Skeptical podcasts and even more Skeptical bloggers and tweeps.
Skepticism is not an organised movement (the collective noun should probably be “an argument of Skeptics”) but groups do keep in touch and do sometimes work together, and this collaboration is made much easier by the internet.
Skeptics’ societies, bloggers and pod-casters have emerged from the grass-roots; there is no centrally organised, centrally funded Skeptics organisation in the UK.
Why do we spell Skeptics the American way?
It’s because Skepticism as movement started in the US where they have important public battles to fight in terms of creationism being taught in schools, maintaining the separation of church and state, and so on. Because it started in the US as a movement, groups in the rest of the world tend to adopt the US spelling to distinguish Skepticism as a movement from skepticism as an approach to understanding problems. Although Skepticism is not an organised movement, some of the American groups are more structured than groups in the rest of the world, simply because of the scale of the challenges they are rising to.
We capitalise Skeptics when we are referring to people who self-identify as part of the Skeptical movement, and we capitalise Skepticism to acknowledge that Skepticism is a community and not just an attitude of mind or a method of finding out about the world, though it is certainly both of those things too.
The water is slightly muddied with regard to climate change – “Skeptics” think that the evidence suggests climate change is due to human factors while “climate sceptics” argue the opposite view.