Only last year the Labor leader was brimming with evangelical fervour as he pronounced climate change as ''the greatest moral challenge of our time''.

Climate change, the Prime Minister said, ''threatens the security and stability of us all'', and a failure to act would be judged harshly by future generations.

But now we see the Government's moral resolve melting away before our eyes.

After the initial symbolic act of signing Kyoto, the Government has been slowly but steadily downsizing its rhetoric and expectations.

The cooling-off from the pre-election passion began immediately after signing the Kyoto Protocol at the Bali climate conference, when the Prime Minister shocked environmental supporters by distancing himself from tougher short-term targets being agreed to by other countries.

Those targets of between 25 and 40per cent reductions by 2020 were said by scientists from the United Nations' Intergovernmental Panel on Climate Change to be necessary to limit global warming to acceptably low levels. Fast-forward to the present, and the Government's emissions targets, set to be announced on Monday, are reported to be as low as a 5 to 15 per cent reduction in emissions by 2020.

The weakening is even more pronounced when you take into account that the 5 to 15 per cent target is based on a baseline of emissions in 2000, where the United Nations uses the tougher baseline of emissions in 1990.

The Prime Minister, who regularly invoked former US vice-president Al Gore and British economist Nicholas Stern as climate change authorities, is now being directly urged by them to stop dragging the chain.

Prior to the election, the rhetoric was all about the need to act now, or even yesterday, while this year the urgency has diminished to the point where the Prime Minister this week pointed to a ''very gradual'' introduction of the emissions trading scheme.

The past insistence that the targets should be dictated by the science has now changed into a formulation which says that the targets should be ''guided'' by the science.

''Australia is the driest inhabited continent on earth and is more vulnerable to the impacts of climate change than any other industrialised nation,'' Rudd said early this year, but the Government's actions have not matched the rhetoric.

If the Government really believes that Australia will be the worst-affected of any developed nation, then why is it not leading the world in advocating a comprehensive global solution?

Why has Australia's international diplomacy been so weak? If we are the country with the most to lose, why has the Government not been campaigning furiously, vocally, and with greater resources to maximise the chances of an effective solution?

The key principle to a successful reduction in emissions is to share the burden as widely as possible; the more countries that participate in a meaningful way, the lighter the burden on all.

If Australia is to convince others of the need for serious emissions cuts, it would need to show that it is willing to support serious cuts itself, and so far it has not done that.

An interesting aspect of this crucial issue is how precisely the same target policy can be presented to mean different things.

For example, let's say Australia has a policy position of a 5 per cent cut in its own emissions by 2020 if there is only a weak level of international co-operation, but 30 per cent if a lot of countries are on board.

Australia could emphasise its intention for 30 per cent targets, conditional on international co-operation, with a fallback of 5 per cent if international participation falls through.

Alternatively, it could emphasise its intention for a 5 per cent cut to emissions, with the possibility of 30per cent if other countries share the burden.

The first scenario is far more likely to help influence other countries in setting serious targets, but it seems, according to reports, that the Rudd Government is pursuing the second approach.

The fact that the Government has delayed the announcement of its targets until straight after the climate conference in Poznan this week also indicates its timidity in negotiating internationally.

There is one issue that illustrates the increasingly blase{aac} attitude of the Government towards the environment, and that is the fact that it is prepared to countenance the loss of the Great Barrier Reef in setting targets.

The Government's chief climate change adviser, Professor Ross Garnaut, has said that if CO2 levels reach 550 parts per million then this ''would be expected to lead to the destruction of the Great Barrier Reef''. Yet Professor Garnaut has ''reluctantly'' concluded that because tougher targets are unrealistic, Australia should attempt to secure a global agreement with 550ppm as the official target, and then down the track encourage countries on to a lower-emissions path.

In other words, the Government's chief adviser is settled on an official global target that sees the end of the reef, in the hope that the world might lift its game at some point in the future.

It's also interesting to consider the major Treasury analysis of climate change policies recently conducted for the Government, which modelled four different policy options based on different carbon dioxide reduction target assumptions.

Two of these options entail CO2 levels stabilising at the 550 ppm level, one at 510 ppm, and one at 450 ppm, a level Garnaut says would ''damage but not destroy'' the reef.

In other words, of the four options modelled by the Government, each one entails damage to the reef, with two of them expected to lead to the destruction of the Queensland icon.

Should the Government have not modelled at least one scenario that entailed no damage to the reef, to see what the economic consequences were?

Why is the Government countenancing the elimination of the Great Barrier Reef at all?

Could it be possible that an Australian Prime Minister, from Queensland, would support a global target entailing the reef's destruction?

''Australia's greatest natural asset'', was how Rudd described the reef during the election campaign last year, ''generating more than $6billion in GDP each year and employing more than 63,000 people.'' But this year the Government refuses to even answer questions about whether the reef is worth saving.

The Opposition is no different, with its environment spokesperson, Greg Hunt, saying that, ''Our goal is to not wave the white flag on the Great Barrier Reef'', leaving the gate wide open for its demise.

The only senior politician to have made a concrete statement is Peter Costello, who has said that no prime minister could pursue a policy allowing the destruction of the reef.

Asked by The Canberra Times about Professor Garnaut's policy recommendation of a 550 ppm target, the former treasurer defended the world heritage-listed reef.

''I don't see how a prime minister could ever reconcile himself to the destruction of the Great Barrier Reef,'' Costello said.

The ex-treasurer's comments set ''a floor in the market'' and will increase the pressure on Coalition leader Malcolm Turnbull, and the Government, to set a policy that protects the reef.

The reason that the Government will not answer questions about the reef is simply that it fears the potential economic costs, or more specifically the political backlash from the potential economic costs, of locking in to reef-saving targets.

How well-founded are these fears?

The Treasury modelling found that in the toughest option, a 25 per cent cut in emissions by 2020 off a baseline of emissions in 2000, average annual GNP growth per capita would be 1.1 per cent rather than 1.2per cent.

Treasury's conclusion was that ''Even ambitious emission-reduction goals have little impact on growth in Australia's economy and in household incomes.''

The boiled-down big picture confronting the Government now is this. Its scientific advisers say that Australia stands to lose more than any other country if serious emissions cuts are not made, and its economic advisers say that ambitious reductions will have little impact on Australia's economy.

So why is the Government baulking?

Part of it is the political fear of particular industries and communities that end up worse off.

The problem with broad-brush Treasury modelling is that it conceals many specific areas of pain, in particular the carbon-polluting industries and the communities that serve them.

But the main fear now is the global financial crisis, which means that any emissions trading scheme will add to some already considerable economic pain.

This week the Australian Industry Group called for a delay in the introduction of the emissions trading scheme due to the global financial crisis, a call which will no doubt become a chorus.

While the Government has resisted such calls, so far, it is already emphasising the slow start to the scheme and the need to compensate disadvantaged industries.

Do not be surprised if the scheme begins very gently, with the real pain not kicking in until well past the next election.

After all, how can the greatest moral challenge of our time compete with the greatest economic challenge since the Great Depression?

David Alexander is Economics Editor.