Independent: Lord Stern, the economist whose report on climate change helped galvanise world leaders behind the green energy movement when it was published 18 months ago, has admitted that the situation is far worse than the assumptions that formed the basis of his ground-breaking report. "We badly underestimated the degree of damages and the risks of climate change," said Lord Stern in a speech in London yesterday. "All of the links in the chain are on average worse than we …