[Skeptic]

To Twig.

A denier denies data. A sceptic challenges interpretation of data.

In the global warming context, a denier may say that the fact of warming is an illusion. Or the fact of greenhouse gas increase. A sceptic like myself may challenge the predictions of climate models, since these do not represent data.

If there is good scientific data available, I will not try to deny it. If that data proves me wrong, I will accept it. However, lots of ideas are a result of differing interpretations of data, and the role of a sceptic is to point out that there may be more than one conclusion to draw, and thus more work to do to determine the best conclusion.