Copenhagen Conference on Climate Change, Day 4: Vulnerable and poorer countries clash with the richer countries

More than half the world's countries say they are determined not to sign up to any deal that allows temperatures to rise by more than 1.5C, as opposed to 2C, which the major economies (richer and powerful countries) would prefer.

But any agreement to reach that target would require massive and rapid cuts in greenhouse gas emissions combined with removal of CO2 in the atmosphere. An extra 0.5C drop in temperatures would require vastly deeper cuts in carbon dioxide and up to £6.5 trillion extra in energy-related investment by 2030, according to the International Energy Agency.

Today the Alliance of Small Island States (Aosis), a grouping of 43 of the smallest and most vulnerable countries, including Tuvalu, said any rise of more than 1.5C was not negotiable at Copenhagen. They are backed by 48 of the least developed nations.

But the UN conference chief, Yvo de Boer, implied this morning that the proposal had little chance of being adopted. "It is theoretically possible that the conference will agree to hold temperatures to 1.5C but most industrialised countries have pinned their hopes on 2C," he said.

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