Warm or cool, which is more terrible?

I found this in an article:
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One of Gore's climate-change "deniers," Robert Giegengack, chairman of the department of earth and environmental science at the University of Pennsylvania, says: "In terms of (global warming's) capacity to cause the human species harm, I don't think it makes it into the top 10."

Of Gore's claim that temperatures are increasing solely because man-made CO2 is trapping the sun's heat, Giegengack says: "That's plain wrong. . . . It's a natural interplay. As temperature rises, CO2 rises, and vice versa. It's hard for us to say CO2 drives temperature. It's easier to say temperature drives CO2."

R. Timothy Patterson, a professor of geology and director of the Ottawa-Carleton Geoscience Centre of Canada's Carleton University, says that "CO2 variations show little correlation with our planet's climate on long, medium and even short time scales. . . . It is global cooling, not warming, that is the major climate threat to the world, especially Canada."
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Although it seems that the credentials of the recent anti-global warming documentary are not so good, I think many arguments in it are valid. When we don't have energy, what could we do? When we have too much energy, we may direct them into proper channels.