Greg Hunt, the Parliamentary Secretary to the Minister for the Environment, is a bright young up and comer. He’s also a brave boy. This week he’s putting on a special showing for MPs of Al Gore’s very own apocalypto, the global warning doco An Inconvenient Truth. Last week his boss, the Prime Minister, declared himself to be “sceptical about a lot of the more gloomy predictions” of climate change.

Do we have a division in the government? Well, it might actually be an idea to first define the issue. That’s the first part. The easy part. Global warming exists. But what causes it? Is it man-made or natural?

Forecasting the apocalypse is normally a nice little earner. It’s doing wonders for Tim Flannery’s career. The Earth’s future may be grim, but saying so has done wonders for Al Gore’s.

We don’t hear as much, though, about the Bob Carters and Ian Plimers – the local scientists who argue that we need to examine the long-term geological record to learn about climate.

Unless you examine the previous warming and cooling periods in detail and prove from then that today’s situation is unique, they say, then current climate change cannot be logically separated from the earth’s complex history of continuous periods of warming and cooling.

We may well be in a natural cycle – a natural cycle which in the past has been fast changing, and slow changing and all states in between.

If this is the situation, then what we’re dealing with isn’t so much an inconvenient truth, but an inconvenient hypothesis.

John Quiggin memorably wrote in the Fin a couple of years back that the local carbon lobby, the Lavoisier Group, is “devoted to the proposition that the basic principles of physics, discovered by among others the famous French scientist Antoine Lavoisier, cease to apply when they come into conflict with the interests of the Australian coal industry”.

Too much of the global warming debate is based on acts of faith – and when acts of faith are involved, you’ll find a whole range of irrational evangelists. Still, hypotheses need to be tested. Does the political will exist to do that?

It’s worthwhile putting those comments from the PM we quoted a moment before in their full context:

JOHN HOWARD, PRIME MINISTER OF AUSTRALIA: I accept that climate change is a challenge. I accept the broad theory about global warming. I am sceptical about a lot of the more gloomy predictions. I also recognise that a country like Australia has got to balance a concern for greenhouse gas emissions with a concern for the enormous burden to be carried by consumers through much higher electricity prices, higher petrol prices, falls in GDP of too dramatic an imposition of what you might call an anti-greenhouse policy. It’s a question of balance.

JONATHAN HOLMES: And clearly that balance depends on how serious you think the threat is and how dramatic you think it is.

JOHN HOWARD, PRIME MINISTER OF AUSTRALIA: And also the pace of technology.

The PM’s clearly no evangelist. He’s not even in St Augustine “Lord, make me good, but not yet” territory.

Peter Costello, however, makes much about his religion. Gore’s gospel was proclaimed in front of News Corp executives at their recent annual meeting. If the PM won’t embrace the new religion, will his Treasurer?

After all, new believers normally embrace their faiths because they offer the promise of salvation.