Photoshopping the Apocalypse
The recent winter solstice witnessed a 'Carl Sagan Blog-a-thon' .
So in celebration of Al Gore's pal, the late author of The Cold And The Dark there follows The Wall Street Journal's warmly cautionary Cold War reminder of how a campaign for the Nobel Peace prize on the Nuclear Freeze ticket devolved into a joke played at the expense of climate modeling's street cred on the eve of the global warming debate :The Melting of 'Nuclear Winter'
All that remains of Sagan's Big Chill are curves such as this ,
but history is full of prophets of doom who fail to deliver, not all
are without honor in their own land. The 1983 'Nuclear Winter "
papers in Science were so politicized that even the eminently liberal President of The Council for a Liveable World called "The worst example ofthe misrepesentation of science to the public in my memory." Among the authors was Stanford President Donald Kennedy. Today he edits Science , the nation's major arbiter of climate science--and policy.
Below, a case illustrating the mid-range of the ~.7 to ~1.6 degree C maximum cooling the 2006 studies suggest is superimposed in color on the Blackly Apocalyptic predictions published in Science Vol. 222, 1983 . They're worth comparing, because the range of soot concentrations in the new models overlaps with cases assumed to have dire climatic
consequences in the widely publicized 1983 scenarios --
"Apocalyptic
predictions require, to be taken seriously,higher standards of evidence
than do assertions on other matters where the stakes are not as great." wrote Sagan in Foreign Affairs , Winter 1983 -84. But that "evidence" was never forthcoming.'Nuclear Winter' never existed outside of a computer except as air-brushed animation
commissioned by the a PR firm - Porter Novelli Inc. Yet Sagan
predicted "the extinction of the human species " as temperatures
plummeted 35 degrees C and the world froze in the aftermath of a
nuclear holocaust. Last year, Sagan's cohort tried to
reanimate the ghost in a machine anti-nuclear activists invoked in the depths of the Cold War, by re-running equally
arbitrary scenarios on a modern interactive Global Circulation Model. But the Cold War is history in more
ways than one. It is a credit to post-modern computer climate simulations that they do not reproduce the apocalyptic results
of what Sagan oxymoronically termed "a sophisticated one dimensional
model."
The subzero 'baseline case' has melted down into a tepid 1.3
degrees of average cooling- grey skies do not a Ragnarok make . What remains is just not the stuff that End of the World myths are made of.
It is hard to exaggerate how seriously " nuclear winter "was once
taken by policy analysts who ought to have known better. Many were
taken aback by the sheer force of Sagan's rhetoric
Remarkably, Science's news coverage of the new results fails
to graphically compare them with the old ones Editor Kennedy and other recent
executives of the American Association for the Advancement of Science,
once proudly co-authored and helped to publicize.