If the global climate change meeting in Bali turns into a tug of war there is no question who will anchor the progressive team: Europe.

The aim of the conference, which begins next week, is to agree on a "road map" for negotiations towards a successor to the Kyoto treaty.

It needs to be one that is deeper (in requiring more ambitious cuts in emissions), broader (in requiring commitments from more countries) and longer (than Kyoto's five-year span, to give more certainty to business investment).

The EU yesterday spelled out what it believes a post-2012 treaty should contain.

Much of it is consistent with what Climate Change Minister David Parker has said New Zealand is looking for from Bali.

The outcome, he said, should contain such core principles as the need for targets to be scientifically credible and the need for a contribution from developing countries, while recognising that developed countries will continue to bear the main burden of reducing emissions.

It should also address the issue of deforestation, which is responsible for up to 20 per cent of global emissions.

The European Union wants a post-2012 agreement to embody the goal of limiting global warming to 2C over pre-industrial levels.

That is the cornerstone, the scientific rationale for an agreement, said Bruno Julien, the EU's ambassador to New Zealand and Australia.

"The latest reports of the United Nations [Inter-governmental Panel on Climate Change] are quite alarming."

Such a goal would require global emissions to stop increasing within 10 to 15 years and then fall to at least 50 per cent below 1990 levels by 2050.

The question would then be what intermediate targets are consistent with that.

The Europeans are proposing that by 2020 developed countries collectively reduce emissions by 30 per cent from 1990 levels and by between 60 and 80 per cent by 2050.

The EU has already unilaterally committed itself to a 20 per cent cut by 2020.

But these are the sorts of numbers that would make the blood drain from a New Zealand climate negotiator's face.

Our gross emissions have risen by 25 per cent from 1990 levels already. Even with allowance for credits reflecting the increase in the forest estate since 1990, New Zealand's net emissions are expected to be 12 or 13 per cent above 1990 levels by 2012.