Sunday, October 18, 2020

David Pogue strikes out as a "science guy" on CBS Sunday Morning on October 18, 2020

Giving the lead story "For Many, Climate Change Finally Hits Home," David Pogue talked about "the dog in the car in summer effect," in the following exchange: "It's funny that we call it the 'greenhouse effect,'" said [Ayana Elizabeth ] Johnson, "'cause most people, like, don't spend a lot of time hanging out in greenhouses!" Pogue said, "I think it should be called 'the dog in the car in summer effect,' because isn't it the same thing? The sun goes into the car, it doesn't fully bounce out, so the car gets really hot inside?" "That's a much better analogy," Johnson said. The significant problem is that neither "analogy" is relevant to the issue of infrared-absorbing gases, such as methane, in the atmosphere. The irrelevance of infrared absorbance to hot greenhouses was pointed out as early as 1909, more than a century ago. From the 2008 IPBiz post Hansen on global warming: 'This is the last chance" : IPBiz notes that, while the term "greenhouse gas" is ever-present in the environmental discussion, it is a misnomer. More than thirty years ago, this misnaming was pointed out in the journal Science: From The "Greenhouse Effect", Robert G. Fleagle and Joost A. Businger, 190 Science 1042 (1975): [G]reenhouses are warmer than the surrounding air because the glass pre- vents the warm air inside from rising and removing heat from the greenhouse. Ab- sorption of infrared radiation by the glass contributes only a little to the warming ef- fect. Polyethylene sheets, even though they are largely transparent to infrared radi- ation, are just about as effective as glass in greenhouses The essential facts were es- tablished by a simple experiment carried out by Johns Hopkins University physicist Robert W. Wood in 1909. He found that two model greenhouses, one covered with glass and the other with rock salt (which is transparent to both short- and long-wave radiation) reached very nearly the same high temperatures. Thus the "greenhouse effect" results from suppression of vertical convection by a rigid lid. The earlier paper in question is Robert W. Wood, Philosophical magazine , 1909, vol 17, pp. 319-320. One would hope after one hundred years, scientists would get the "greenhouse" issue right. So, as to Pogue, the "dog in car" is not a better analogy, it is not an analogy at all. Also, of note in the Pogue story Johnson offered a climate-change refresher for correspondent David Pogue: "We burn all these fossil fuels, all these greenhouse gases go up in the air. It's carbon dioxide. It's methane. And they create this layer of gas that is basically like a blanket on top of the planet." That "blanket" traps heat from the sun that would have bounced back out into space. * The moment of nature was an early snow in San Juan National Forest near Durango, Colorado. See also Illegal campfires plague San Juan National Forest


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