Because of stuff like this.

>I am curious as to why no one listens or puts stock in the opinions of the Canadian climatologist Tim Ball or Bell or whatever his name is:
>
>http://www.canadafreepress.com/2007/global-warming020507.htm
>
>
>
>>Man-caused global warming is a hoax. Possibly the most grand and expensive one in history.
>>
>>That being said, it's going to be tough to dispute a report that doesn't exist. The only thing that has come out is the Summary for Policymakers. The data will not be released until May, after they have modified it to fit the political "summary".
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>>http://www.canadafreepress.com/2007/harris020207.htm
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>>>I find it difficult to believe that soooo many scientists have incorrectly bought into the idea of global warming. Yet these people continue to try.
>>>
>>>>>http://www.crooksandliars.com/2007/02/04/scientists-offered-cash-to-dispute-climate-change/
>>>>
>>>>They're just doing their law-mandated "corporate duty" - protecting the value of their outfit for their shareholders.
>>>>
>>>>The laws, as they now stand, give corporations the upper hand. Moral reasons are no excuse for risking shareholder value. Imagine if people operated their lives on the same premise!