By Roger Harrabin
BBC environment analyst
Modest temperature rises would affect millions of people, scientists warn
The UN's climate change chief has accused Europe's politicians of shifting the goalposts in global talks on climate change.
The EU agreed at the Bali climate summit in December 2007 to bankroll clean technology in developing countries if they agreed to take appropriate actions to curb emissions growth.
The fragile deal was reached after marathon talks.
But EU politicians are now asking for more action for their money. They want developing countries to produce plans to cut emissions across their entire economy before getting cash help from the EU.
Yvo de Boer, secretary of the UN climate programme (UNFCCC) told BBC News: "Quite frankly the language from (EU) ministers re-writes some of the fundamental agreements we made in Bali.
"I don't think it's constructive to enter into a negotiation by trying to change the fundamental principles on which you've just agreed the negotiation will be based."
Mr de Boer urged EU national leaders meeting at a summit in Brussels on Thursday to re-affirm that they would stick to the agreement they made in Bali without turning the screws on developing countries.
The EU's lead climate negotiator Jos Delbeke said this week's summit would define Europe's position.
"Action [from developing countries] should be meaningful," he later told BBC News.
"Otherwise how can we say to the EU citizens: please pay and we are completely unsure if we are going to land on 2, 3 or 5 Celsius. I think we are still within the spirit of the Bali action plan.
Mr de Boer wants a commitment to the Bali agreement from EU leaders
"We are opening up negotiations so I think it's fair and really time that everybody sets out what they really want. On finance what we agreed to in Bali - we are going to respect it… but the political process is bringing elements on the table. "
These are the early shots in the war of words that will intensify through the year in advance of the Copenhagen meeting in December designed to forge a new international climate agreement.
Mr Delbeke said he believed there would be a global agreement in December. He offered an insight into a deal to break the long-standing climate deadlock between the US and China - the world's major emitters.
The previous Kyoto deal failed in the US because it did not include China. Mr Delbeke suggested a way to attract both superpowers was an agreement on emissions standards for key industrial sectors like steel, cement and aluminium.
Such a deal would protect sectors vulnerable to international competition.
Discussions are in the early stages but the EU has been talking to the Obama administration about offering cash for clean technology to countries like China if it agrees in turn to cap emissions in key industrial sectors and adopt cutting-edge technology.
Such an agreement could replace the Clean Development Mechanism (CDM) under which firms in developing countries are paid by rich nations if they install clean technology on a project-by-project basis.
The CDM has been criticised because some of the projects would have been done anyway, even without funding from the West.
The CDM is particularly controversial in the US. Mr Delbeke said a sectoral approach would need to be environmentally ambitious and light on administration.
"It is a major challenge to design such a system," he told the Carbon Market Insights conference in Copenhagen. "But it is worthwhile. It widens and deepens the participation of emerging economies in the carbon market."
Analysts said it could take two years for the intellectual framework of such an approach to be thought through. This will alarm scientists who last week demanded urgent cuts in climate-warming emissions.
Some observers at the conference argued that an outline deal including sectoral targets could be sealed later this year even if India did not agree.
"There are only two key players, the US and China," said one. "Obama needs to be able to prove to his own voters that China has made concessions - and this is one way of achieving that."