In a week when most of the public attention was on Tony Abbott's achievement of his solemn promise to abolish the carbon tax, Shorten promised to bring back taxes on carbon pollution as soon as Labor returns to office. Not in the same form, but as an emissions trading scheme, which is about where the now-repealed carbon tax would have been at the next election, had it not been repealed this week.

In doing so, he acknowledged that Labor had made serious mistakes during its term of government in the way that it conceived, sold and failed to properly defend action on climate change. He admitted that Labor in government had several times dropped the ball in addressing what former prime minister Keven Rudd had once called the great moral challenge of our time. But, he insisted, it was not going to do so again.

If the polls are any guide, Labor might well win the next election on the back of Abbott's unpopularity, not least over a perception of broken promises and deceit over heavy spending cuts to health, welfare and education. Abbott has more than two years to retrieve his standing with voters, but, on the evidence so far, he has failed either to make a connection with voters as a statesman or as an effective governor. He was not greatly trusted or admired even in opposition, but was remarkably effective in tearing down the Rudd and Gillard governments and in creating a lasting public impression that Labor was inept and hopeless, a shambles likely to bring the nation to moral and economic collapse.

The damage that would be caused by unilateral movement to a carbon tax and, later an emissions trading scheme, was at the core of Abbott's argument and, later, his claim of a mandate to undo the carbon tax as one of the first tasks of government.

His campaign was greatly assisted by poor Labor politics, typical of the party's seeming incapacity to get its act together. Although John Howard, in his last years of government had belatedly recognised the need to be seen to be doing something about climate change, and had committed the coalition to an emissions trading scheme, the electorate in 2007 perceived, rightly, that united Coalition enthusiasm for serious action was lagging, and that a significant section of the party - not at that stage including Abbott - was resistant.

Action on climate change, including signing the Kyoto compact, was part of a package which made Labor, and Rudd, more in tune with the mood, and an increasing sense of urgency, particularly among younger Australians about doing something.

In government Rudd signed at Kyoto, created a department of climate change and began serious work on the structure of an ETS. But government became bogged down in the detail, too busy to maintain the public case and the momentum. It acted as though it had won the argument, when the argument was just beginning.

Rudd, minister Penny Wong and her associate Peter Garrett and ministers generally began to fail to promote action on climate change as a general cause and as a top-priority policy. The government itself may not have lost the faith, but it was failing to propagate it, and it was failing to communicate properly even to many of the core constituencies who by now took the science as read, were willing to embrace significant national sacrifice - if not, one sometimes suspected, personal hardship - and who wanted constant reinforcement of the policy, the programs, and its moral, social and economic basis.

Climate change became bureaucratised, dull, difficult and, by virtue of not being talked about day by day, a second or third-order matter. The apostles may not have wavered, the broader electorate was becoming more and more bored. Because politicians no longer seemed infused with a sense of urgency, or moral mission, it progressively became something that was intellectually favoured by a majority, but hardly any longer the emotional or idealistic reason for voting in a particular way.

Some of the zealots were already suspicious of Labor's real dedication to the cause, and fearful that inevitable concessions and inducements to business would water down whatever came out of the sausage machine. Labor's cold-blooded demolition of the reputation of Malcolm Turnbull, an advocate of climate change, paved the way for the destruction of his leadership by a cabal of climate change deniers, who found in a mouldable Tony Abbott an unlikely, but as it proved, unexpectedly able chief advocate.

In any administration, initial good intentions suffer as leaders are "distracted" by fresh problems and events. The GFC might serve as the shorthand, but there were other areas in which initially pure policies were seen to have been watered down. A ruthlessly pragmatic Rudd - before the reinvention of him between leadership doubts - ever a captive of pressure groups, focus groups and opinion polls. He could talk tough and seem focused, but he was often a walkover in close-quarter negotiations with state premiers, big business, and lobbies.

It was little surprise that his ETS was defeated, first, from the left. The Greens thought that climate change action was morally necessary but that the package Rudd and Wong were putting up was so weak and so unlikely to make a difference that it was worse than doing nothing.

Had the Greens gone along with the Rudd-Wong scheme, a tax on carbon pollution, but a very mild one, would be now a feature of the economic landscape. That might provide a rueful thought for the Greens, but, from where they come, there is not the slightest sign of contrition.

It was also entirely typical of that modern Labor that among the first to pragmatically argue that the matter was no longer galvanising people and could be put on the back burner was Julia Gillard, notionally the champion of the Labor Left. With Labor's proposals in tatters, and an international climate change conference in Copenhagen in 2009 having proved disappointing in galvanised united world action, Labor, including at the time Shorten himself, had little appetite for revving up the issue for an early 2010 election.

At that stage, however, most of the population still believed in the need for action, and Labor would have been more likely than not to win the election. That would have disposed of Abbott, however well he fought the election, and, most likely have installed a reasonably moderate Liberal, such as Joe Hockey in the leadership, unlikely to have resisted a fresh try on meaningful action.

While Gillard deserves considerable credit for ultimately negotiating an ETS, she was also to make the popular cause more difficult by her promises that there would be no carbon taxes under a government she led. When she changed her mind in negotiating a workable government after the election, she failed, signally, to explain and defend what she had done. The most effective part of Abbott's campaign against her was in calling her a "liar" for the broken promise, rather than in mounting a convincing case against her plans.

In the process of getting its legislation through, Labor worked the lobbies and the constituencies effectively but failed, yet again, to bring the public along, too. That's a task before Shorten, and one in which he has previously demonstrated little skill.

Monday, however, showed at the least that he has a good speechwriter.

"In late 2009, this nation was on the verge of making a decision about which we could have been collectively proud. We could have made this parliament a place of inspiration, with a national response to climate change, supported by both government and opposition,'' he said.

"It was a policy of both government and opposition that built upon the previous government's decision - a government not of our party - but consistent with the best practice in the world ...

"But, since that time, the hope that we could develop a national commitment has been frittered away. For his part, our current Prime Minister wrested away the leadership of the Liberal Party from the person who believed most in the evidence and the need for a response. For our part, we walked away from calling an election which the nation was entitled to have.

"We did the second-best thing. We worked to achieve a national response, but we settled for second best, transforming the international pricing of carbon into a carbon tax.

"But we were right to have international pricing. We were right to support an emissions trading scheme. We were right to have climate change as a political priority of the previous government. We were right to establish the Climate Change Authority, the Clean Energy Finance Corporation and the Australian Renewable Energy Agency. We were right to back the renewable energy target. We were right to listen to the scientific world.

"We had a responsibility to work within the political realities to achieve the best national outcomes for the best international response. For this, Labor does not apologise. From this Labor does not resile. We are not sceptics. We believe the science. We understand that what is necessary is an effective international solution. In that international solution we aim for best practice, to be among the leaders, working with the progressive, continuously testing the facts. In that international solution we want practical outcomes, the best solutions, not just some vague promises.

"We would prefer to be part of a national consensus, but where we cannot we shall advocate our position. We want to nurture the debate.''

It reminded me somehow of Arthur Calwell in 1966. But also of Gough Whitlam's capacity - sometimes - to go hard, and ultimately successfully, on a moral cause.

Liberals in Parliament professed to be amazed and delighted at how Labor committed itself to continuing taxes on carbon pollution. It was, Christopher Pyne said, an albatross around Shorten's neck. And the issue with which Abbott would destroy Labor at the next election.

That's a judgment call. If it is true that it was the weakness of the Gillard government that lost Labor the last election, there is a serious prospect that it will be Abbott who will lose the next election, rather than Shorten, hardly an inspirational character. If he does, he can, and will, claim no less a mandate than Abbott does now.

But, just as importantly, business, industry, miners and and the broader institutions give Labor a chance at the next election. Pleased as some might be, for the moment, that the carbon pollution taxes are gone, they now know that they have to prudently plan for the possibility, perhaps, probability of a resumption. If it proves that Shorten is rather more on the money than Abbott about a drift towards ETS or carbon taxes, some of the annoyance at Labor could switch to anger at the Coalition for the paperwork, frustration and unnecessary obstacles put in the way of what was probably inevitably going to be long-term policy.

Perhaps. Or perhaps instead there will be a hysterical advertising campaign, with an equally hysterical media campaign, to show that Labor is a high-taxing party, determined to drag the economy into the dust. And, on the moral plane, wicked for failing to support the policy alternative - " direct action" - promoted by Abbott as the superior way of reducing emissions without unduly burdening Australian industry and the economy. And a redoubling of efforts to prove Labor as likely to bring back the boat people, to drive up government debt and deficits and return us generally on the road to economic ruin.

The outcome will not depend only on the facts, the logic and the moral imperatives. It will depend as much on the noise and tumult, on there being a continuing debate and on who is invited to listen. This is not one for the backroom boys but the front of the shop.