Rajendra Pachauri, head of the Intergovernmental Panel on Climate Change (IPCC), warned delegates last weekend:

“The science is very clear – it’s loud, articulate and incontrovertible. The time for contemplation and vacillation is over. Let’s move on, and that’s the decision we hope to get in Bali.”

At the same time, Indonesia, South Africa and Kyoto newbie Australia took the bold step of releasing a four-page draft agreement urging rich countries to slash emissions.

“Preventing the worst impacts of climate change will require (developed nations) to reduce emissions in a range of 25 - 40% below 1990 levels by 2020,” the draft urged.

Following this, delegates reconvened on Monday with senior ministers replacing civil servants as hard negotiations began. But despite the UK and EU supporting the draft, which the UN had published on its website, the US maintained staunch resistance to the proposed 25-40% cut. The ever flexible US delegate Harlan Watson attacked the IPCC findings, saying that they were based on “many uncertainties”.

“It’s pre-judging what the outcome should be,” he said. “We have problems with defining the numbers up front.”

On Tuesday, Ichiro Kamoshita, Japan’s Environment Minister, cut a three tier birthday cake to commemorate the tenth birthday of the Kyoto agreement. There were only mooted celebrations, though, as the atmosphere worsened with the EU growing increasingly frustrated by the US position.

And the mythical 25-40% target proved to be the key sticking point for progress, prompting UN Secretary-General Ban Ki-moon to intervene and try to ease the tension.

“Realistically it may be too ambitious if delegations would be expected to be able to agree on targets of greenhouse gas emission reductions,” he said. “Sometime down the road we will have to agree on them.”

But Sigmar Gabriel, German Environment Minister, was in no mood to wait.

“How can we find a roadmap without having a target, without having a goal?” he argued.

Proceedings worsened on Thursday as the EU and US both accused the other of attempting to block progress.

“We are a bit disappointed that the world is still waiting for the United States,” said Portugal’s Secretary of State for Environment Humberto Rosa. “The U.S. has been using new words on this – ‘engagement’, ‘leadership’ – but words are not enough. We need action.”

The US countered that it was ready to agree to a new treaty in Copenhagen in 2009, but flatly refused to back down on targets.

“Those who are suggesting that you can magically find agreement on a metric when you are just starting negotiations – that in itself is a blocking element,” said White House representative James Connaughton. “We will lead. But leadership also requires others to fall in line and follow.”

Such a position led Nobel Prize winner Al Gore to criticise his country’s behaviour upon arriving in Bali.

”The United States is principally responsible for obstructing progress in Bali,” he said. “Over the next two years the United States is going to be somewhere it is not now. You must anticipate that.”

There were some successes – notably the agreement to a fund to help developing nations adapt to climate change and limit deforestation. But delegates were openly admitting that even this may not be finalised within the week.

As crunch time beckoned at the end of the week, however, hopes of a deal were raised as the EU-US impasse appeared to ease. And on Saturday, delegates announced triumphantly that a deal, of sorts, had been struck – not to reduce CO2 emissions, but to reach a new global agreement by 2009.

While the so called ‘road map’ to a successor to the Kyoto Protocol does not contain any text on binding emissions reductions, it was hailed as a success by U.N. climate chief Yvo de Boer.

“This is a real breakthrough, a real opportunity for the international community to successfully fight climate change,” he said. “Parties have recognized the urgency of action on climate change.”

The goal of Bali, Ki-moon had said at the top of the conference, was to launch negotiations. This has certainly been achieved, but the summit has also exposed the protracted fight that lies ahead. It has to be hoped that delegates will leave Bali not with a feeling of ‘job done’, therefore, but with a commitment to act.

Andrew Laughlin is a journalist and currently writes for total:spec magazine. For more on total:spec, click here.