The controversial British climate change sceptic appeared at the National Press Club yesterday to debate Richard Dennis, of the Australia Institute.

Among his statements about the ''non-problem'' of climate change - and the startling assertion that carbon dioxide is not a pollutant - the peer brandished some evidence of his own.

Not evidence of anthropogenic climate change, obviously, but evidence of his title.

This week the House of Lords published an impertinent ''cease and desist'' letter demanding Lord Monckton stop claiming to be a member of the British upper house (where hereditary peers are no longer guaranteed a seat).

Asked about this yesterday, Lord Monckton turned to the debate's moderator with what can only be described as a lordly air.

''Sir,'' he said, and whipped out his British passport, nestled conveniently in an interior pocket of his well-cut suit.

''Would you be kind enough to read out the words in this box on this passport page?''

The moderator was kind enough.

''The holder is the right honourable Christopher Walter Viscount Monckton of Brenchley,'' he recited.

Lord Monckton thanked him.

''The House of Lords says I am not a member of it. My passport says I am. Get used to it!''

Further, he said, ad hominem questions of such a ''futile and drivelling'' nature were beside the point.

Lord Monckton's point, driven home with plenty of vivacity and some charm, was that climate change is a ''non-problem''.

But it was somewhat over-shadowed by his theatricality (he once mocked the Australian accent with a deliberately mangled pronunciation of ''carbon tax''), the large fan club present (he was applauded loudly and two men gave him a standing ovation), and his mood switches when challenged on questions of evidence - be it of climate change, or of his aristocratic credentials.

In a sign of just how polarised the debate is, security guards were posted around the room, and the club's chief executive warned against shoe-throwing.

Dennis countered the Viscount by saying sensible people look at the evidence and act accordingly. He likened climate change action (which he says should come in the form of a price on carbon) to taking out insurance.

''We can bet the house in case Lord Monckton is right or we can insure the house in case he's wrong,'' Dennis said.

Sshhh. Don't mention the House.

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