British and United Nations officials predicted yesterday that it could take a year after next month's Copenhagen climate change summit to conclude a new global treaty to tackle greenhouse gas emissions.

This significantly extends the timeframe Ban Ki-moon, UN secretary-general, had hoped for only two days earlier. There is growing consensus that time is too short before Copenhagen to settle the myriad divisions between countries and -produce a document necessary to form the basis of a binding treaty to succeed the Kyoto protocol.