Doha - The world's poorest nations on Wednesday called for significant financing to cope with the impacts of global warming, setting up a potential clash with rich countries that could slow progress on reaching a global climate pact by 2015. Pa Ousman Jarju, chair of the 48-member Least Developed Countries at the talks, said it was too early to say the disputes over financing could spill over to other areas of negotiations, including the extension of the Kyoto Protocol, which will expire this year, and a work plan to prepare for the 2015 deal. The American negotiator Jonathan Pershing agreed."The commitment in the first part was a voluntary agreement on the part of donor countries to collectively provide something approaching $30bn and we exceeded that commitment. The second part was to mobilise $100bn by 2020 and we are working on that," Pershing said. The bickering over financing is the latest clash between rich and poor nations over the past decade that have undermined efforts to reach a deal that would keep global temperatures from rising more than 2°C, compared to pre-industrial times. "The climate change phenomenon has been caused by the industrialization of the developed world," Ban told The Associated Press. "It's only fair and reasonable that the developed world should bear most of the responsibility."Many rich nations, including the US and EU countries, are demanding the 2015 pact include commitments from developing nations who are expected to produce the bulk of emissions in the decades ahead. "Climate change is happening much, much faster than one would understand," he added. "The science has plainly made it clear: it is the human beings' behavior which caused climate change, therefore the solution must come from us."