The House of Lords says that Christopher Monckton is not entitled to claim he is a member of that House, but he disputes this. The internet is full of scientists carefully debunking the claims about climate change made by him, but he is similarly impervious to correction.

Put simply, Lord Monckton is a case study of the emphasis placed by the media on confidence over content. A harder question for the media, however, is why they have given so much prominence to climate sceptics with no qualifications in science when they pay virtually no attention to immunisation sceptics without qualification in epidemiology or fluoride sceptics with no qualifications in chemistry or biology?

So, how do you debate someone who is impervious to evidence? It’s not easy, but here are a few suggestions.

Step one is to agree with them. If Lord Monckton really believes that climate change is a conspiracy of self-interested “warmists”, then talk to the audience about the real consequences of such a conspiracy.

Does Lord Monckton really believe that NASA under George Bush and the CSIRO under John Howard were part of this conspiracy? Does he believe that Andrew Peacock, John Howard, Brendan Nelson, Malcolm Turnbull and Tony Abbott (at least half of the time), not to mention Arnold, Margaret Thatcher and Angela Merkel are in on it as well?

Of course it is not just conservative politicians who accept the science of climate change. Ralph Hillman, the head of the Australian Coal Association, Mitch Hooke, the head of the Minerals Council, do and even Marius Kloppers, the head of BHP, not only accepts the science but supports the introduction of a carbon tax.

Does Lord Monckton really believe that these politicians and business people are all part of some warmist conspiracy?

The next step is to embrace genuine scepticism. One of the reasons that so many hard-working and sincere scientists are genuinely flummoxed by entertainers such as Lord Monckton is that they see themselves as sceptics. That is, the whole basis of scientific inquiry is one of scepticism and questioning, and the whole point of peer-reviewed publications is that science is critically evaluated before it is published.

In claiming scepticism Lord Monckton, who is not a scientist, is actually claiming science for himself. But as a sceptic, Lord Monckton should have no problem accepting the possibility that he himself is wrong. To do otherwise would be an admission that he is simply a zealot.

So in debating Lord Monckton it is important to ask him, and the audience, to think about the consequences if he is wrong.

What if NASA, CSIRO and the world academies of science are right when they tell us that the world is warming, that this warming is caused by our pollution and that the only way to stop it warming further is to reduce our greenhouse gas emissions? We insure our homes against the unlikely event of fire and we plan to spend more than $50 billion on 12 new submarines in case we are one day attacked but, by Lord Monckton’s logic, we shouldn’t pay a price for pollution as an insurance premium against catastrophic climate change.

The third point to make in such a debate flows on from the second. Sceptics increasingly argue that while climate change might be happening the costs of tackling it will be far greater than the costs of ignoring it. In order to maintain such an argument, however, they have to make their conspiracy theory far bigger than the one linking NASA, Greenpeace, John Howard and Marius Kloppers. Indeed, to maintain the argument against a carbon price Lord Monckton has to include the entire economics profession as well.

A good question to ask climate sceptics in general, and one I put to Lord Monckton, was why he was so opposed to a carbon price and so quiet about Tony Abbott’s far more expensive direct action scheme. Tony Abbott has not found a single economist to publicly back his scheme, and an analysis by the Australia Institute estimates that bureaucrats will likely have to process more than 150,000 grant applications to achieve the Coalition’s target of 713 million tonnes of abatement by 2020.

The administration costs will likely be enormous.

So if you ever wind up in a debate with a sceptic try not to take the bait. They want to be attacked; because their conspiracy theory requires them to be seen as possessing dangerous knowledge, which makes powerful people want to silence them. And they want to sound conservative when, of course, their views about climate science, and if you scratch the surface a range of other things, are actually quite extreme.

We live in a democracy, and I hope we always respect free speech. Climate sceptics aren’t the only people in the country who knowingly or otherwise mislead the public, but there is no doubt that their co-ordinated efforts to mislead people have slowed down our efforts to prevent the catastrophic climate change our scientific bodies warn us of.

Only the media can explain why they have given so much attention to extreme and ill-informed views about climate change and choose not to give a similar platform to a range of other conspiracy theorists. But when these debates do go ahead, my advice is that it is best to focus on the risks and consequences and unlikeness of the sceptics being right rather than try and prove that they are wrong.

Not even the House of Lords can convince Lord Monckton that he is wrong.

*Dr Richard Denniss is executive director of The Australia Institute, a Canberra-based think tank.