Warmist economics professor Paul Krugman suggests that trace amounts of harmless, invisible, natural atmospheric gas may lead to "catastrophe"

The Truth About Climate Change, Still Inconvenient - NYTimes.com

The ringers (i.e., nonscientists) at last week’s hearing weren’t of quite the same caliber, but their prepared testimony still had some memorable moments. One was the lawyer’s declaration that the E.P.A. can’t declare that greenhouse gas emissions are a health threat, because these emissions have been rising for a century, but public health has improved over the same period. I am not making this up.
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But it’s terrifying to realize that this kind of cynical careerism — for that’s what it is — has probably ensured that we won’t do anything about climate change until catastrophe is already upon us.