Business Green: A leaked letter from the United Nations’ climate chief suggests the Copenhagen climate summit failed because the presence of 130 world leaders paralysed decision-making and the Danish presidency backed the US and other western nations over the interests of the poor. The revelations — made as the UN climate talks resume in Bonn today — come in Yvo de Boer’s candid letter, written to colleagues days after the summit broke up in acrimony in December. More than 130 world leaders …