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Post by eclipse on Nov 24, 2012 14:04:41 GMT 9.5
Hi all, what do we all think of this one? The team's calculations suggest that covering an area of a little more than 60,000 square kilometres with reflective sheet, at a cost of some $280 billion, would be adequate to offset the heat balance and lead to a net cooling without any need to reduce atmospheric carbon dioxide. However, they caution that it would be necessary to control the area covered very carefully to prevent overcooling and to continue with efforts to reduce our reliance on fossil fuels. www.sciencedaily.com/releases/2008/12/081222114546.htm
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Post by anonposter on Nov 24, 2012 15:32:50 GMT 9.5
The albedo of the Earth is one of the things that has an effect on the global mean temperature so it should at least be physically possible.
Probably better to do it in an area close to the equator that has mostly dark rocks (though Earth rocks tend to be relatively light).
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Post by Roger Clifton on Nov 25, 2012 12:34:09 GMT 9.5
Really, Eclipse!
If you have read an article using the words, "without any need to reduce atmospheric carbon dioxide", you have let a climate denier spout nonsense. You should have set fire to the magazine immediately, stamped on the ashes, shouting "first we must stop the CO2 emissions!"
(Then, if necessary, you might apologise to the other people in the library for the distraction.)
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Post by eclipse on Nov 25, 2012 12:48:48 GMT 9.5
Roger, sure that's the ideal. Prevention is better than the cure, and all that. The problem is that we're NOT doing it: or haven't you noticed? The problem is that American Denialism and Western nuclear aversion are both still going strong. Meanwhile, the climate science seems to be developing a shriller and more dangerous tone. It may already be too late to 'prevent' this. We are like a lifelong smoker being asked to both give up the habit AND seek chemo, because it's already too late. I know there are side-effects, but if this particular 'chemo' has the least side-effects, then I say do it!
IF (and I still have to see other studies on this) Global warming can just 'go away' for $280 billion put into reflective sheeting across 60,000 square kilometres of desert, then Australia's Great Victoria Desert could 'solve' Global Warming 10 times over. $280 billion sounds like a lot of money, but in reality is just a tiny fraction of the cost to solve Global Warming through clean energy schemes. $280 billion would probably not even solve Australia's clean energy requirements even if it purchased 56 1 Gigawatt nukes, because we'd still have to clean up our transport systems and wean them off oil. Australia only produces a TINY fraction of the world's Co2. Solving Global Warming through global clean energy schemes and energy efficiency is going to cost several tens of trillions of dollars and take decades. But what if we gave ourselves more time, and just coated a tiny fraction of this planet's deserts in shiny sheets? There's still acid oceans to deal with, and coal's infamous soot and pollution and terrible health costs. But that never stopped us before!
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Post by quokka on Nov 26, 2012 20:48:39 GMT 9.5
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Post by David B. Benson on Nov 27, 2012 7:45:57 GMT 9.5
Nice pix.
Consider the Empty Quarter of the Arabian Peninsula.
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Post by eclipse on Nov 27, 2012 14:04:29 GMT 9.5
Sorry all, this party's over. The wiki didn't dig deep enough into its own sources. I'm still trying to verify it but it seems like the $280 billion (or 60k MILES or around 120k km's) only buys enough reflectivity to deal with the warming so far. By 2050 it has to be repeated, and later in the century the same amount of plastic is required EACH YEAR! I *think* I'd rather see that amount of money going into nuclear power instead, hey?
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Post by edireland on Nov 28, 2012 1:51:10 GMT 9.5
That is not really accurate, since that would imply that the warming driven feedbacks would happen despite there being no warming to drive them.
If we reverse all warming occuring now, we don't get into the thermal runaway that is supposed to occur.
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Post by eclipse on Nov 28, 2012 20:07:57 GMT 9.5
Except that the wiki is anticipating that the carbon emission trend would continue. Adding reflective plastic sheets covering 67,000 square miles (170,000 km2) of desert every year between 2010 and 2070 to reflect the Sun’s energy.[50][51] This technique can give globally averaged 1.74W/m2 of negative forcing,[3] which is insufficient to offset the 3.7W/m2 of positive forcing from a doubling of CO2, but is still a very significant contribution and is sufficient to offset the current level of warming (approx. 1.7W/m2). However, the effect would be strongly regional, and would not be ideal for controlling Arctic shrinkage, which is one of the most significant problems resulting from global warming. Furthermore, the total area required during 2010-70 is larger than all non-polar deserts combined. en.wikipedia.org/wiki/Solar_radiation_management#Reflective_sheetingThe actual quote from the actual study is here: "To offset all new forcing over the period 2010-2070 will require the covering of nearly 67,000 square miles per year, an area about the size of North Dakota or Missouri. By comparison, around 61,000 square miles in the U.S. are devoted to roads and parking lots and 80,000 square miles of U.S. soil is planted in wheat alone each year (120)." www.global-warming-geo-engineering.org/Albedo-Enhancement/Surface-Albedo-Enhancement/Calculation-of-Coverage-Areas-to-Achieve-Desired-Level-of-ForcingOffsets/Desert-Area-Coverage/ag29.html
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Post by grlcowan on Nov 29, 2012 2:42:31 GMT 9.5
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Post by eclipse on Nov 30, 2012 21:50:52 GMT 9.5
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