Bloomberg: World leaders wasted a decade debating whether global warming is happening, and now need to act quickly to limit its effects, a former chairman of the United Nations Intergovernmental Panel on Climate Change said. The pace of greenhouse-gas emissions risks locking in thousands of years of higher sea levels, as well as damaging marine ecosystems such as coral reefs, melting sea-ice and acidifying the oceans, said Robert Watson, now chief scientific adviser at the U.K. environment …