Talks on global warming in the United States next week may be complicated by differences among developing countries as their climate policy positions diverge.
All agree that the rich should take a lead in tackling climate change after enjoying more than two centuries of economic growth fuelled by burning coal and oil.
The differences will emerge on when and under what terms developing nations shoulder a greater burden in cutting their own growing greenhouse gas emissions.
Climate summits next week in Washington and New York will feed into talks which are often simplistically portrayed as hinging on getting rich and poor to agree a formula.
The Bush administration hosts a summit for "major economies" on energy and climate change in Washington later next week, following a U.N. climate summit in New York on Monday.
Both are meant to contribute to long-running U.N. talks to agree a successor to the Kyoto Protocol, the global deal on cutting climate warming carbon emissions which expires in 2012.
Beneath a show of unity splits exist among developing countries.
"(Sub-groups) reflect differences in priorities generated from different national interests," said Alf Wills, head of South Africa's climate negotiating team.
Developing nations engage in a single block called the "G77 plus China", and a common rallying cry is to remind rich nations that they haven't lived up to a promise to finance the fight against climate change.
"We still haven't seen the commitments coming through," said Wills.
But under that umbrella various shifting groups include: rapidly developing economies, tropical forested countries, oil-producing states, small island states and the poorest, least developed nations.
Small island states and forested nations may benefit from tough climate policies, while oil producers would lose out if, as intended, these dampened demand for fossil fuels like oil.
Big, rapidly developing countries are also showing splits.
India, for example, differentiates itself from China which is now neck-and-neck with the United States for the title of world's biggest carbon emitter, and coming under increasing international climate policy pressure as a result.
Nitin Desai, an expert who is on Indian Prime Minister Manmohan Singh's Council on Climate Change, said it was unfair to lump China and India two together.
"Our per capita emissions are one fourth of theirs while their GDP (gross domestic product) is not four times larger than ours," he said.
"India has achieved very substantial energy efficiency... by that yardstick India has achieved more on climate change than China."
But the two have much in common, too, worried that energy constraints will strangle their economic growth. Like all countries, they also want to minimize the impact of climate change expected to trigger dangerous weather extremes and higher sea levels.
"Everyone wants to do something about climate change, it's a difference in priority. It's not a simple formula, but it's not impossible," said South Africa's Wills.
China says it is committed to the climate change cause.
"The Chinese government attaches great importance to the issue of climate change," said foreign ministry spokeswoman Jiang Yu.
To reach agreement all countries, developing and developed, will have to recognize the problem as a shared one, said John Ashton, climate change representative at Britain's foreign ministry.
"We can't do this on a blame game, 'after you' mentality... whether China, India, Europe or the U.S.," he said.
(Additional reporting by Y.P Rajesh in New Delhi and Lindsay Beck in Beijing)