British Climate change minister Greg Barker speaks in front of a new interactive Google Earth map showing the impact of a rise in temperatures on Earth, in London July 14, 2010. Climate change scientists and politicians must be "more realistic and less preachy" if they are to persuade a sometimes sceptical public to support the urgent action needed to tackle global warming, Barker said on Wednesday. REUTERS/Paul Hackett (BRITAIN - Tags: POLITICS SCI TECH ENVIRONMENT)