Naked Science Forum
Life Sciences => The Environment => Topic started by: Mike HR on 08/07/2005 08:12:04
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Probably a crazy idea, but...
In busy parts of the sky aircraft vapour trails spread out and merge together resulting in less sunlight striking the ground beneath them.
If we flew aircraft, maybe specially adapted to increase the volume and reflectivity of their vapour trails, over the vulnerable Greenland and Antarctic ice sheets, laying down a sort of 21st century parasol above them, would this slow the rate of melting?
This reflective sheen of water vapour would probably only need to be in place during the summer months and then only during the daytime, being allowed to dissipate at night so that it did not inhibit heat radiation from the ice at night.
Mike Harding Roberts
http://www.bagley123.wanadoo.co.uk/global-warming.htm
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Hmmmm. Perhaps not a crazy idea, but probably an ineffective one. Your idea is actually an answer to a question, is it not? The question is "How can we solve the Global Warming problem without doing anything about the enormous amounts of Carbon Dioxide we are pumping into the earth's atmosphere?" Your idea is an effort to answer this question.
My answer to the question differs from yours. It is "We probably cannot prevent increasing temperatures from occurring in our atmosphere in the decades to come without addressing the enormous amounts of CO2 coming out of human activities such as gasoline engines and coal burning. Therefore we need to attack the disease rather than the symptoms- by reducing our burning of these substances and therefore reducing the amount of CO2."
chris wiegard
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The ice sheets are melting, its something that has happened many times in the distant past and will happen many times in the future ,and the processes involved like the changing ocean currents are not really understood. maybe we're speeding it up through global warming, maybe we're not, but blocking out the sun with vapour trails wont make any difference, its a bit more complex than the sun striking the ice.
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ukmicky and chris wiegard, thank you for you replies.
Chris, I agree with you that we should reduce CO2 emissions (a theme I explore in http://www.bagley123.wanadoo.co.uk/global-warming.htm) but if we don't, won't or can't we may need to start thinking about how we might address symptoms.
ukmicky: yes, as you say there's more to ice melt than direct sunlight. The questions I'm hoping an expert in the field will answer are: would shielding ice with vapour trails make ANY difference to ice melt rates; has this idea been considered before; and if not would any expert out there like to do a back of the envelope calculation to assess the cooling effect. Though maybe you are that expert - I'd be interested if you could point me to any papers that detail the relative melting impacts of sea temperature, air temperature and direct solar radiation.
Mike HR
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I'm not an expert
But I do know that jet engines produce large amounts of soot which would add to the large amounts of soot already floating around the arctic and Antarctic regions.
Soot in the atmosphere acts like a blanket and traps heat underneath which then alters the air temperature and global weather patterns.
Also clean ice reflects most of the sunlight that reaches it but when particles of soot settle on it, it gets dirty and so absorbs more sunlight which causes more heat to be trapped. With inevitable results, which is part of the problem now?
So your idea would only speed up the melting process.
Sorry