I imagine because the editors are embarrassed by his latest column, they didn't even include it on the home page of the latest issue. You sort of have to dig for it.
He says that he has become convinced by the arguments of a Martin Hertzberg that he met on a Nation Magazine cruise in 2001. Hertzberg is a retired scientist, whose insights into climate science are tied to the 3 years he spent as a meteorologist in the army. I myself would not ordinarily look to a retiree on a Nation Magazine cruise for guidance, but that's just me. (And don't go accusing me of agism, because I'm ready for the rocking chair myself.) Hertzberg confides to Cockburn that is all about "water vapor" and not H2O. It almost sounds like that guy telling Dustin Hoffman in "The Graduate" the magic word "plastic". >>As Hertzberg says, water in the form of oceans, snow, ice cover, clouds and vapor "is overwhelming in the radiative and energy balance between the Earth and the sun.... Carbon dioxide and the greenhouse gases are, by comparison, the equivalent of a few farts in a hurricane." And water is exactly that component of the Earth's heat balance that the global warming computer models fail to account for.<< I really haven't paid too much attention to this stuff in recent years now that I don't find myself in the same neck of the woods on cyberspace as James Heartfield, spiked-online's token Marxist. But I seem to remember that the global warming skeptics harped on water vapor all the time. It is not as if Hertzberg figured this out all on his own. It is in fact so much of a standard argument of the skeptics that it is dealt with on the gristmill website faq: http://gristmill.grist.org/story/2006/12/22/215837/90 (Part of the How to Talk to a Global Warming Skeptic guide) Objection: Climate scientists never talk about water vapor -- the strongest greenhouse gas -- because it undermines their CO2 theory. Answer: Not a single climate model or climate textbook fails to discuss the role water vapor plays in the greenhouse effect. It is the strongest greenhouse gas, contributing 36% to 66% to the overall effect for vapor alone, 66% to 85% when you include clouds. It is however, not considered a climate "forcing," because the amount of H2O in the air basically varies as a function of temperature. If you artificially increase the level of H2O in the air, it rains out immediately (in terms of climate response times). Similarly, due to the abundance of ocean on the earth's surface, if you somehow removed all the water from the air, it would quickly be replaced through evaporation. This has the interesting consequence that if you could somehow instantly remove all CO2 from the atmosphere, the temperature would begin to drop, causing precipitation to remove H2O from the air, causing even further drops, in a feedback effect that would not end until no liquid water was left, only ice sheets and frozen oceans. CO2 put into the air by burning fossil fuels, on the other hand, stays in the atmosphere for centuries before natural sinks finish absorbing the excess. This is plenty of time to have substantial and long-lasting effects on the climate system. As the climate warms in response to CO2, humidity rises and increased H2O concentration acts as a significant amplifier of CO2-driven warming, basically doubling or tripling its effect.
