Did the late scientist Carl Sagan once advocate for increased carbon dioxide emissions? That's what the Washington Examiner claims in a recent commentary by Shannon Goessling, Executive Director of the Southeastern Legal Foundation, which advocates for "limited government" and "the free enterprise system":
In the 1970s and '80s, climatologists and astrophysicists were setting off alarms about pending global cooling and "the new ice age." Headlines in major weekly news magazines warned of a cooling catastrophe, with experts like famed astronomer Carl Sagan calling on industrialized countries to produce more carbon dioxide to offset the pending disaster.
The claim that scientists predicted an imminent "ice age" in the 1970s is a common myth employed by conservative media outlets who invariably cite headlines in "news magazines" rather than scientific literature. A 2008 paper in the Bulletin of the American Meteorological Society actually reviewed the climate research published in the 70s and concluded that "global cooling was never more than a minor aspect of the scientific climate change literature of the era, let alone the scientific consensus" and "emphasis on greenhouse warming dominated the scientific literature even then."
As for the allegation that Sagan called for higher CO2 emissions, William Poundstone, who wrote a Sagan biography, says "that claim is new to me." According to Poundstone, Sagan was concerned about greenhouse warming as early as the 60s:
That claim is new to me. While I can't prove a negative, I would be very skeptical of it unless they've got some period documentation. Sagan was at any rate one of the first to worry about global warming. He was a principal architect of the current understanding of Venus, showing that the carbon dioxide in its atmosphere caused it to be much hotter than astronomers of the time had imagined. In my Sagan biography I write (p. 45):
"One day in Berkeley, Carl told Ronald Blum (he had moved west, too) that he was worried about the carbon dioxide in the air. The burning of fuel was creating more carbon dioxide. This would increase the earth's greenhouse effect and warm the globe with disastrous consequences. At the time, that was an incredible if not crazy thing to say. It could not have been later than 1963."
This was based on an interview with Ronald Blum, a college friend.
Science historian Spencer Weart also said he had never heard the claim that Sagan called for increased CO2 emissions: