Image caption Climate curbs or development? The BASIC countries are firm on their priorities

EU plans on aviation, "climate aid" and the West's past CO2 output are set to be divisive at the UN climate summit.

India has tabled a paper arguing that the EU's plan to include international flights in its emissions trading scheme violates the UN climate convention.

Meanwhile, technical analysis for a group of developing countries says Western nations have a duty to absorb CO2 over the coming decades.

It also says the West is not living up to promises on climate finance.

The summit opens at the end of the month in Durban, South Africa.

Earlier this week, the powerful BASIC group - Brazil, South Africa, India and China - agreed a common position during a meeting in Beijing.

Among other things, their ministerial declaration asserts that "unilateral measures on climate change, such as the inclusion of emissions from international aviation in the EU-ETS (emission trading scheme), would violate the principles and provisions of the convention and jeopardise the effort of international co-operation in addressing climate change".

From next January, airlines operating flights beginning or ending at EU airports will be included in the carbon pricing scheme.

The EU is not going to back down from the scheme at this late stage; so the Indian paper sets the scene for a new intractable conflict within the already strife-ridden climate negotiations.

Weight of history

We cannot continue to delay making the decisions... as there will not be sufficient time for countries to take action Joseph Gilbert, Environment minister, Grenada

Potentially even more damaging is the technical analysis provided to the BASIC ministers by an expert advisory group.

Working from the standpoint that western nations have a heavy responsibility for climate change because they industrialised first through fossil fuel burning, the experts reviewed various studies on what a fair and equitable allocation of future emissions might look like.

The analysis, seen by BBC News, is that industrialised countries should become net absorbers of CO2 rather than net emitters.

In the first half of this century, it concludes, the developed world should absorb 239-474 billion tonnes of carbon dioxide while developing countries continue to emit. That, the experts say, would be fair and equitable.

Analysts say it is not clear how far the BASIC bloc will push this line in negotiations.

Although the West's historical role is acknowledged in the UN climate convention, demands that Western countries become net carbon absorbers would not be countenanced.

'Not new'

Also included in the expert advice is a damning analysis of "fast-start" climate finance provided by western countries.

Image caption Manmohan Singh's India is taking a progressively harder line as the talks approach

At the Copenhagen summit two years ago, developed nations agreed to provide $30bn (£19bn) of "new and additional" money over the period 2010-2012 to assist developing countries in "greening" their economies and protecting against climate impacts.

Though much of the money has been pledged, the BASIC analysis says that only a small proportion is truly "new and additional" - the majority coming from aid budgets or programmes that were in existence before Copenhagen.

Since that ill-starred meeting, a number of development charities have made the same point.

The BASIC ministerial declaration also re-iterates the call for developed countries to pledge new emission cuts within the legally binding framework of the Kyoto Protocol.

At the Beijing meeting, ministers referred to continuation of the protocol's binding curbs as "non-negotiable", sources say.

However, Japan, Russia and Canada have made it plain that they will neither negotiate on the pledges they made unilaterally at Copenhagen, nor put them inside the Kyoto Protocol.

A number of other western governments are reluctant, and the US has never been part of the treaty.

'Irresponsible' delay

In a bid to build bridges across this apparently impassable divide, Norway and Australia recently proposed that a new legal agreement should be wrapped up by 2015.

But in recent days, signals from the Japanese and Russian camps have indicated that they cannot countenance a deal until 2018.

Japan is particularly concerned about losing economic competitiveness given that its main economic rivals are not covered by any internationally binding targets.

"The world's number one emitter (China) has no obligations under Kyoto, the number two emitter (US) is not a party and the number three emitter (India) has no obligations," Akira Yamada of Japan's Ministry of Foreign Affairs told the specialist reporting service Point Carbon News recently.

In response, the Alliance of Small Island States (AOSIS) issued a statement describing calls to delay the agreement as "reckless and irresponsible".

"The world's top climate scientists have told us that global emissions need to peak well before 2020 if we're to hold global warming to below 2.0C (3.6F) above pre-industrial levels... as everyone agreed last year [at the UN summit in] Cancun", said Joseph Gilbert, environment minister of AOSIS chair Grenada.

"We therefore cannot continue to delay making the decisions, to 2018 or 2020, as there will not be sufficient time for countries to take action."

In Copenhagen, governments agreed to review progress on carbon-cutting in 2015, with the implication that commitments would be tightened if the science demanded it.

Observers point out that delaying a political agreement would neuter that review process.

Finance-sector companies have also warned it could also weaken low-carbon investment.

In public, the developing world is as united as ever, with AOSIS shoulder-to-shoulder alongside both the BASIC group and the oil-rich Gulf states.

But behind the scenes, there are concerns that some major developing countries are seeking to blame the West for failure to progress partly in order to conceal their own desire to stave off carbon curbs.

"The US, China and India are in cahoots over this," said one experienced observer of the UN process.

"And it's about time that China and India were called out."

Those two governments point out that under the UN convention as it stands, the developed West is obliged to take the lead in reducing emissions and providing finance.

But some - particularly among the small island states - argue that if the developing world giants stick to that position rigidly, there is no chance of keeping the global average temperature rise below 2C from pre-industrial times.

Follow Richard on Twitter