George Bush's top scientific advisor has delivered the strongest statement yet from within the US administration that greenhouse gas emissions caused by human activity are to blame for climate change.


	President Bush has invited world leaders to Washingtonlater this month to discuss climate change

Professor John Marburger said it was more than 90 per cent likely that mankind was causing global warming and that the earth may become "unlivable" without reductions in CO2 output. Read More