A sceptic is someone who doubts or questions something, usually in a cautious or skeptical way. They do not easily believe things without evidence or proof. Full definition
Environmentalists often refer to climate sceptics as climate deniers, claimed by their opponents to be a deliberate attempt to ally them in the public mind with far right wing holocaust deniers. (earthtimes.org)
In 2008, Heartland decided to host a conference for climate sceptics in New York — it would be the first of eight conferences for skeptics and deniers (six of them were held in the US, one in Germany and one in Australia). (desmogblog.com)
Whether it is the PDO, or another natural oscillation (my money's on the AMO), which is holding global temperatures more or less constant its significance is not just as a weapon for sceptics in the future. (realclimate.org)