I just watched this film, paying particular attention to the parts that most people see as objectionable (that Global Warming will - and is - causing more frequent, stronger hurricanes).

Err... I don't understand why this section is so heavily criticized. Katrina was used as an example of how storms can gain power as they go over warmer waters; he does not state in the film that Katrina was formed due to Global Warming. And (I think) the science he presents is accurate and perfectly plausible - as the Earth's temperature increases, ocean surface temperatures rise, leading to warmer and more moisture-rich tropical environments that are more favorable for hurricanes to form in and lending them greater magnitude.

Is this not correct? If it isn't, could someone please explain where the facts are being divorced from the presentation?