Global Warming: There's a stir about because the Bush administration used a heavy hand in editing the EPA's annual environmental report. Here's a representative edit:

But in the "Global Issues" section of the draft returned by the White House to E.P.A. in April, an introductory sentence reading, "Climate change has global consequences for human health and the environment" was cut and replaced with a paragraph that starts: "The complexity of the Earth system and the interconnections among its components make it a scientific challenge to document change, diagnose its causes, and develop useful projections of how natural variability and human actions may affect the global environment in the future."

I'll just dip my toe in here. I think I'd call the edited version a proper scientific conclusion. And the original, while threatening in the most vague way possible, isn't really a scientific statement as much as it is a banality taken out of it's proper context. Climate change does have global consequences. And, if climate change occurs in the warming direction (remember that 25 years ago, the big concern was "the coming ice age"), most of them are likely to be good. Beyond that, not much can be proved.