Here's a tiny clue that climate change might be serious; every Australian city except Hobart and Darwin is looking at desalination or waste water recycling. Vast swathes of once irrigated farmland are lying idle. Food prices are soaring. We are burning more coal to make up for shrinking hydro. Australian and world grain production is declining despite population growth. Sure Sydney had a cool summer but Adelaide was like an oven. Maybe next year will be Sydney's turn.

So far we have coped but it's getting harder. However I see no reason to expect any reduction in these trends. It seems an unfair burden on today's children to grow up in a world of extremes. The IPCC has indeed made wrong forecasts, for example recent Antarctic ice melt is worse than they predicted. We may only have to wait a decade to see a 30 cm sea level rise, not the end of the century. Those who urged taking no action will not be remembered kindly.

Don Aitkin is right about the need for due diligence on global warming, though a Royal Commission would probably be ignored in much the same way as were the recent British High Court decision which found Al Gore's film to be a political not a scientific statement and enquiries by the House of Lords and the US Senate. What's difficult is finding a common basis of fact. The Antarctic ice cap is an example. The Wilkins ice sheet, part of which broke off recently, represents less than 0.40 percent of the total Antarctic cap. It melts to varying degrees during every Antarctic summer. Overall, however, Antarctic ice cover is increasing and approaching record levels in some areas. When the annual Wilkins melt is used as an example of looming disaster, dispassionate discourse and scientific analysis are the losers.

Don,

Your suggestion that Pascals Wager is essentially similar to the Precautionary Principle has two flaws. The belief, or otherwise, of the existence of God , based upon the given premises, affects a handful of people. Mainly family, friends or colleagues. So the impact of making the wrong decision is very localised.

Secondly, the Precautionary Principle starts from a place where something is 'known' or 'observed', unlike the hypothesis presented in Pascals Wager. It says that initially, in the absence of stronger data, we (the collective we) should plan for Y if the data consistently indicates that X is causing Y.

The correlation between CO2 and climate change has been getting progressively stronger over the last twenty years. So in fact we've moved well past the point where reasonable people would apply the Precautionary Principle.

The science is overwhelmingly pointing to the need to act.

Simon Roz

Then how do you explain the lack of temperature increase over the last 8 years when CO2 has to continued to increase significantly?

Don't tell me. Its um, Earth Hour right?

There is merit in much of this article and I too struggle with the urgency of action to reduce CO2 emissions. I look to the actions of our political leaders and I assume, perhaps wrongly, that they can avail themselves of the very best advice. Unfortunately all that I see is that after getting that advice all they produce are symbolism and empty gestures.

While the ALP's policy on nuclear power has long been inconsistent, e.g. you can only operate three uranium mines but there is no cap on how much they can produce, the party has been consistently in favour of burning coal, and exporting coal for others to burn which produces massive CO2 emissions.

If the ALP, who have consistently been against the use of nuclear power turned around and said, 'this is so serious that we will close coal power stations and commission nuclear power stations', then I would see that CO2 emissions are a huge problem. The Government action is a bit like Kevin Rudd's stance on China, good on him for his rhetoric, but that is all that it is. We continue to export to China, and until he leads economic action against China by stopping exports of coal and gas, his actions will continue to speak louder than his Mandarin.

If we did that former Prime Minister John Howard and his Liberals would still be in power. Don't you know anything? Climate change, political change, change ... it's all the same. And then the idiot went and made it much easier by introducing work choices!

President George W. Bush. You're next!