KEY POINTS:
Among the bumf circulated to delegates at last weekend's Labour Party conference was an unofficial one-page flyer lamenting the party's dismal progress towards cutting greenhouse gas emissions. The anonymously authored document sarcastically suggested delegates try to spot the difference between Labour and National when it came to combating global warming - its point being that there wasn't one. Labour was as woefully deficient as National in setting long-term targets for cutting emissions.
That may have been true before the Prime Minister took the rostrum for her speech. It wasn't afterwards. Labour's position on emissions had registered a shift of seismic proportions, opening a policy chasm between it and National.
Helen Clark even seemed to be out-greening the Greens with her ultra-ambitious talk of New Zealand being a world leader by aiming to become "carbon neutral" and "truly sustainable". As a circuitbreaker to end Labour's cycle of woes, the speech more than did the job.
It pushed the pledge card fiasco into the background. It dispelled the notion Clark's third-term Government has run out of ideas. With the wider Labour Party categorising climate change as one of its "big issues", the speech delivered exactly what conference delegates had been looking for from the leadership.
The speech also cast to a wider audience, demonstrating to doubting voters on the centre-left that Labour still has a soul. It put a new lustre on Labour's tarnished brand. It fitted neatly into Labour's strategy of building national identity to make people feel good about themselves and feel good about Labour. It made National's attempt to "green" itself look extremely pale.
But all these positives could melt away if Labour's rewrite of climate change policy does not match the idealism. It is difficult to see how it can do so.
"Carbon neutrality" is a leap of gargantuan proportions. It would require that for every bit of carbon dioxide that ends up as greenhouse gas, an equivalent amount is extracted from the atmosphere and absorbed or buried.
That goes way beyond the Kyoto Protocol, which requires New Zealand to cut emissions by 2012 back to the net amount being pumped into the atmosphere in 1990. So much for that target. Emissions are instead running at more than 20 per cent above 1990 levels - and they are growing. Even the Greens shy away from "carbon neutrality", preferring to set a goal of reducing net emissions by 60 per cent over the next 40 or so years.
But while Clark's speech talked of New Zealand becoming carbon neutral, she was careful to say that was an "aim". Since the speech, she has further described the target of zero net emissions as "aspirational", saying "it's not magic wand territory".
Having raised expectations, she cannot disappoint. One way of meeting them may be to set benchmarks for progress towards carbon neutrality, with some sectors of the economy moving towards the goal faster than others.
The public is realistic. The key thing for Labour is that it is now talking about a radical plan for tackling global warming, even if the plan turns out not to be quite as radical as first hinted.
Timing is everything. It is better to catch a wave of public opinion just as it is rising, rather than having it dump all over you.
In that regard, Labour believes National has seriously misread the speed and extent to which public alarm is mounting. National's recently released "Bluegreen Vision" discussion document accepts something needs to be done and flags some tentative first steps.
But Don Brash still sounds like someone in climate change denial. His and National's moderate stance is out of fear of getting out of sync with big business and farmers.
However, the increasing vogue overseas for companies to become "carbon neutral" shows market pressures are starting to force producers to "green" themselves.
The "food miles" fuss which has seen New Zealand exports flown into the European market under fire is a further wake-up call for the agricultural sector here.
Clark needs a marked shift in private sector attitudes to global warming if she is to implement the kind of sticks needed to go with the carrots to make it economically far more costly to emit greenhouse gases.
Labour's abandonment of its modest carbon tax raises major questions about whether it has the bottle to bring in the more radical measures Clark's language would seem to be indicating.
Labour has claimed it simply did not have the numbers in Parliament to pass the tax into law. The tax was flawed and unpopular. That essentially is why it was dropped.
But the only really effective way of meeting climate change objectives is to put a price on the use of carbon. Labour has been talking of introducing an emissions trading scheme after 2012 which would require polluters to buy permits - something also floated by National.
National has offered to work with Labour on producing a bipartisan policy - a sign National knows it is vulnerable and that it wants climate change off the political agenda. Having mounted a raid to capture the high ground of the debate, Clark is not going to oblige.
That high ground, of course, has long been the preserve of the Greens. They see more pluses than minuses in Clark muscling into their territory. Since the protracted debate over genetic engineering, the Greens have lacked a high-profile issue. Clark has pushed climate change centre-stage.
The Greens' response is to force Clark to put her money where her mouth is. They have drafted a series of private member's bills on greenhouse gas emissions which will make Clark look hypocritical if Labour does not back them.
Clark's speech was not intended to squeeze the Greens out of Parliament. That would be counter-productive. The speech was targeted at those centre-left voters who have become disenchanted with Labour and who might switch to the Greens.
The Greens' supporters are unlikely to be impressed by Clark's Road to Damascus conversion to radical action on greenhouse gas emissions. After all, is this the same Prime Minister who, as the hydro storage lakes were emptying back in March, told Parliament that if it came down to a choice between New Zealanders going without power and having a coal-fired power station to give it to them, "I know what I am going to choose"?
The Greens might well ask.
