NO DARK and smoke-filled room greeted the man Prime Minister Kevin Rudd decries as part of a worldwide conspiracy of sceptics intent on sabotaging any new climate treaty.

Instead, a gathering of avowed ''sensible'' environmentalists listened closely in the plush surrounds of Melbourne's Park Hyatt Hotel to a speech by Britain's Lord Christopher Monckton, who dismissed as ''bogus'' fears of global warming.

Lord Christopher Monckton believes a treaty in Copenhagen next month would create a new tyranny in world affairs. Credit:Jerry Galea

''Those who have been fostering what is essentially a baseless scientific scam have being trying to make the obvious sound absurd and the absurd sound obvious, and we are now going to turn the tables on them,'' Lord Monckton said.

With a rapid-fire computer slide-show as counterpoint to the famed warnings by former US vice-president Al Gore, Lord Monckton set out to an Institute of Public Affairs conference what he called a litany of lies by the United Nations on climate change. Most egregiously, Lord Monckton said, UN reports on climate change ignored evidence of global temperatures that were higher during medieval times than now.