Actually, we only need the first two. The latter two are about what we should do. And if the first two are true, it would not be surprising if the latter two are also true.
Not necessarily. In fact, I think the third one is hardest. I have yet to encounter anyone who has been willing to give a scientifically based answer to my popular question of "What is the optimum average global temperature?" If the answer to the third one is no, then 1 and 2 become irrelevant. And 4 seems to be something that many environmentalists literally do not care about at all. Environment uber alles.
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SmartMuffin - Because anything less would be uncivilized - http://img.imgcake.com/smartmuffin/barkleyjpgde.jpg
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