Alan's powers of revision continue to astonish. He writes : "It is amazing how these results have held up in the intervening 27 years."
Really ? Has he forgotten the five order of magnitude difference in darkness between the "Apocalyptic predictions" Sagan adduced in 1984 , and the recent modeling of Robock et al ? It projects project optical depths one or less- that's a million times brighter than the optical depth of 20 postulated 20 years ago. Alan predicts surface coolings in the single digits where TTAPS projected a global deep freeze. Run the time -temperature integrals and Alan's predictions add up to a most a few hundred degree -days. In contrast to Alan's efforts , the widely advertised TTAPS worst-case model turned the sun off like a light bulb, reducing insolation by a factor of a million, for a biblical 40 days and 40 nights. predictably producing subzero cooling that totaled 22,000 degree-days- an effect a hundred times more severe than that Robock recently published . 22,000 degree-days F is twice the chill of an honest to god winter in Alaska or Siberia' Has alan forgotten thatthe worst- and most heavily publicized of Sagan's 'Apocalyptic predictions ' featured pervasive frost on the equator, and tempertures that stayed subzero long enough for Sagan to opine " the extinction of Homo sapiens cannot be excluded. Merely running his models longer does nothing to justify Alan's* *claim that : " In fact our new climate model simulations show that nuclear winter was correct, and that it would last longer than we thought then." For details, and links to a graphic comparison of Robock & Sagan's 2007 and 1983 results see my correspondence in *Nature* , July 7 2011 http://www.nature.com/nature/journal/v475/n7354/full/475037b.html?WT.ec_id=NATURE-20110707 > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To view this discussion on the web visit https://groups.google.com/d/msg/geoengineering/-/bwYcfeNmaQoJ. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
