LONDON (AFP) – World leaders heading to UN climate talks next week must not be distracted by "flat-earth" sceptics who deny humans are to blame for global warming, Prime Minister Gordon Brown warned Saturday. "With only days to go before Copenhagen, we mustn't be distracted by the behind-the-times, anti-science, flat-earth climate sceptics," Brown told The Guardian newspaper ahead of the landmark UN summit in the Danish capital. "We know the science. We know what we must do. We must now act and close the five-billion-tonne gap. That will seal the deal." Government advisor Nicholas Stern estimated that 10 billion tonnes...