Reuters: Top climate scientists will blame mankind more clearly than ever for global warming next week but may struggle to drive home the message in a report that uses the term "uncertainty" 42 times. The 'language gap' between scientists and the policy makers, public and media they seek to alert is proving hard to bridge. Scientists say uncertainty is inevitable at the frontiers of knowledge - in, for instance, calculating how much of Greenland will thaw or how fast temperatures will rise by 2100 - but...