U.S. News and World Report: A leading British climate change economist warned Tuesday that those who doubt the science of global warming are confused–and said their skepticism should not derail efforts to strike a climate deal in Denmark. Nicholas Stern, who wrote a British government report on global warming, said hackers who posted documents snatched from the climate research unit at the University of East Anglia had muddled the debate at a critical moment. Critics of the science behind global warming …