Global warming may have made Hurricane Gustav slightly stronger and wetter, some scientists said today, but few were rushing to make a specific connection between climate change and stronger storms.

A top US government scientist has performed a U-turn on climate change, saying global warming is not responsible for the recent increase in Atlantic hurricanes.

Human-caused global warming is visible in the air, water and melting ice and destined to get much worse in the future, an authoritative world report will warn.

It has been 2,000 years and possibly much longer since the Earth has run such a fever.