By Richard Black Environment correspondent, BBC News website

Bali's spectacular rice terraces form a backdrop for speakers

EU ministers are threatening to boycott a US-led climate summit next month over the Bush administration's opposition to firm cuts in greenhouse gas emissions.

The row comes during the penultimate day of UN climate talks in Bali, where progress on outstanding issues is slow.

Europe wants developed countries to agree cuts of 25-40% in emissions from 1990 levels by 2020, but the US and Canada want a more flexible agreement.

But Spain's environment minister said the boycott threat was partly tactical.

The EU is trying to accelerate progress at the talks, which are proceeding so slowly that the head of the UN climate convention said he was "very concerned".

The hours

Several European ministers said if there was no agreement on targets, the EU would boycott a meeting next month of the "major economies" or "big emitters" group called by the White House.

President Bush established the group earlier this year. Some observers see it as an attempt to undermine the UN process.

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"No result in Bali means no major economies meeting, said Germany's Environment Minister Sigmar Gabriel.

"This is the clear position of the EU."

However, his Spanish counterpart Cristina Narbona told Spanish radio: "I'm convinced that if the German minister made this move... he believes it's useful to do so at the moment - it's an initial move, tactical to an extent.

"What we have to see is whether, in the coming hours, we need to make (more) moves of this kind or agreements can be reached."

US Under Secretary of State Paula Dobriansky said the Bali conference was designed to be the start of a two-year negotiating process leading to a successor agreement to the Kyoto Protocol.

"We don't have to resolve all these issues... here in Bali," she said.

Arriving at the meeting from the Nobel Peace Prize ceremony in Oslo, Al Gore called on the US to change its stance.

"My own country, the US, is principally responsible for obstructing progress here in Bali," said the former US Vice President.

House of cards

A European boycott of the major emitters' meeting would be embarassing domestically for the Bush administration, which has publicised the process as an economy-friendly route to curbing climate change.

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But it would be unlikely to have a long-term influence. The US presidential election is less than a year away, and a new incumbent would be likely to disband the big emitters process.

Observers from environmental groups are more concerned that the US/Canadian stance could mean the Bali summit fails to agree on the need for binding targets by 2009.

The UN shares those concerns. "If we don't manage to get the work done in time on the future, then the whole house of cards basically falls to pieces," said Yvo de Boer, executive secretary of the UN Framework Convention on Climate Change (UNFCCC).

Apart from emission cuts, outstanding issues include the transfer of clean technologies to developing countries, and ensuring a sustainable flow of funds to the poorest nations to help protect their economies and societies against the impacts of climate change.

The US/Canada bloc also wants major developing countries to accept that they will have to cut emissions too.

Developing country delegates are concerned by this, partly because they feel western countries are trying to distract attention from their historical responsibility for climate change and from the failure of many nations inside the Kyoto Protocol to make meaningful progress towards its targets.

"We are concerned at the attempts to create a new framework which may result in the dilution of specific and timebound commitments on emission reductions by developed countries," said India's Science and Technology Minister Kapil Sibal.

Tale of two Chinas

Observers say that privately, some delegates from major developing countries acknowledge they may have to accept firm targets at some point, but there is considerable suspicion that the West may try to foist targets upon them that could retard their economic growth.

Yu Qingtai from the Chinese delegation told Reuters news agency that richer countries were "dodging their moral responsibility" to provide the developing world with clean technologies.

"They either view this as a gesture of charity or generosity, not as a moral or political obligation," he said.

"They always try to shift the focus to the market, ignoring the fact that for developing countries, we know the technologies are out there but these are the most expensive technologies and we cannot afford them."

Tree line

On the conference fringes, there has been some progress on forestry.

Many developing countries, including the host nation Indonesia, want the West to pay for preserving what remains of the tropical forests.

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The Stern Review last year confirmed that protecting forests was the cheapest single approach to curbing climate change, as well as contributing to other environmental issues such as conserving biodiversity and safeguarding fresh water supplies.

Although committed to the idea in principle, some western governments are concerned about reliable management of forest funds, corruption, the longevity of forest protection agreements, and the possibility that some money might be claimed to protect forests that were safe anyway.

At the Bali meeting, the World Bank has launched the Forest Carbon Partnership Facility (FCPF), which will explore how forest conservation can be financed and managed.

Donors have so far placed $165m in its coffers.

The Bali meeting is scheduled to close on Friday evening; but previous UN climate meetings, including the seminal Kyoto summit a decade ago, have overrun their scheduled end-points, and some delegates suggest this one may follow the trend.

Richard.Black-INTERNET@bbc.co.uk