Contrails are the clouds that form from the exhaust of jets flying at high altitude. By injecting small amounts of silver iodide into the jet fuel, contrails could be made to last longer, allowing them to grow larger. Seed the upper atmosphere with silver iodide in the early morning, and the resultant clouds will reflect solar radiation for hours before they dissipate. But don’t seed them in the afternoon or at night, because nocturnal clouds act as insulation. The net result: global cooling.-- ldischler, Aug 07 2006 CNN News story http://archives.cnn.../contrails.climate/ [hippo, Aug 07 2006] Effects of Contrails studied http://www.scienced...08/020808075457.htm [jhomrighaus, Aug 07 2006] Stratospheric Welsbach seeding for reduction of global warming http://patft.uspto....03186&RS=PN/5003186A patent assigned to Hughes Aircraft that suggests dispersing nanoparticles of barium oxides in jet exhaust high in the atmosphere. These particles would reflect visible light but allow IR to pass unimpeded. Such ideas have apparently spawned a "chemtrail" paranoia. [ldischler, Aug 07 2006] One of the chemtrail sites. http://www.lightwat...ls/smoking_gun.html"Proof of global atmospheric geoengineering," or so he says. [ldischler, Aug 07 2006] Global Dimming film http://www.bbc.co.u..._prog_summary.shtmlMentioning Europe's particle pollution reduction as having a real effect on the Sahelian monsoon [django, Aug 08 2006] Albedo management Ping_20Pong_20Albedo_20EnhancementUsing white biodegradable ping pong balls [django, Aug 08 2006] Tit for tat http://www.sportssm...om/images/funny.jpg [ldischler, Aug 08 2006] Flying on holiday 'a sin', says bishop http://www.dailymai...228&in_page_id=1770Those who do not reduce their eco-footprint will probably burn in hell - tit for tat [django, Aug 08 2006] Hmm worried about the polution aspect --- what affect does silver iodide have in the atmosphere... Can't you use an organic salt?-- madness, Aug 07 2006 No one knows what effect contrails have on surface temperature. There's a bit of evidence (see link to CNN story) that contrails, like cirrus clouds, reduce the variability in surface temperatures that you normally expect between nighttime and daytime temperatures.-- hippo, Aug 07 2006 [hippo] If contrails are produced all the time, they will reduce the daytime temp (reflecting solar radiation into space) and increase the night temp (reflecting IR back to the ground). So the net may be zero. But by tweaking the contrails in a cyclic fashion, with more heat being reflected away during the day, the net wouldn’t be zero.[madness] Yes, there are probably other materials you could use. I just picked the best known one (which was discovered, BTW, by the brother of Kurt Vonnegut).-- ldischler, Aug 07 2006 I thought I heard something about changes in the sky immediatley after september 11th when they shut down all of the Air plane traffic into and out of the US. Let me see if I can find it.
See Link for news story.
Sorry I didnt read the first link before I posted mine. Feel free to Delete.-- jhomrighaus, Aug 07 2006 I keep reading this as 'Cooling the earth with entrails'.-- angel, Aug 08 2006 Ha! That would have been better.-- ldischler, Aug 08 2006 This is advocacy for combating global warming. So [marked for deletion].-- django, Aug 08 2006 No it's not; it's saying 'Assuming global warming is genuine and should be combated, here's a way of doing so'.-- angel, Aug 08 2006 //This is advocacy for combating global warming//Tit for tat, django?-- ldischler, Aug 08 2006 It is widely accepted (but unproven) that climate change is caused by human activity.
Yes, there are natural fluctuations in temperature which make it difficult to see how much is down to us and how much is down to nature, but there is a demonstrable trend which coincides with burning of fossil fuels.
Obviously, our first action should be to reduce the use of fossil fuels. It may well be too late for that, on it's own, to prevent a significant change.
So I don't think that generating many diverse, original ideas for combating global warming is advocacy as such.-- Frankx, Aug 08 2006 //Obviously, our first action should be to reduce the use of fossil fuels.// Well, it's said that even if we stopped using fossil fuels completely, the temperature of the earth would continue to increase, simply because it takes so long to absorb the CO2 already out there. On the other hand, you'd only have to change the planetary albedo a little to erase the entire effect of using fossil fuels. (BTW, django only tagged this because I tagged one of his for advocacy.)-- ldischler, Aug 08 2006 Yes tit for tat a bit, but let's get over it, and we'll let the mods decide whether it's advocacy or not.
//simply because it takes so long to absorb the CO2 already out there// Are you sure of this? I heard that Europe's CO2/particle pollution reduction efforts during the 1990s are probably the reason for the return of the monsoons to the Sahel [see link]. So that's only one and a half decade to have a genuine effect.
Moreover, I agree with the other posters: the effect of this idea would be very small since you're still using huge amounts of jetfuel which release CO2 into the atmosphere.
There are probably better ideas for planetary albedo management, like seeding the seas with white biodegradable ping pong balls [see link].-- django, Aug 08 2006 //huge amounts of jetfuel//The thing about jet fuel is that you're already using it. The idea piggybacks on domestic aviation. All that's added is a small tank of silver iodide solution and a valve to inject it in the fuel line. The fuel use is the same.-- ldischler, Aug 08 2006 [django], if you are bringing tit for tat, I would like a linked image. For research purposes.-- bungston, Aug 08 2006 //The fuel use is the same.//
True, but that's the problem.
Even the Bishop of London now officially calls flying on holiday a 'sin' for Christians. [see link].
He's actually right. We have to reduce CO2 emissions. And air travel is one of the biggest contributers. Those who do not help reducing CO2 emissions will die in horrible agony and burn in hell for eternity. Tit for tat.-- django, Aug 08 2006 The Bishop of London also calls shopping on Sundays a sin. I'll accept his view on sinfulness (for those who accept the concept) but if he wants to reduce CO2 emissions, he should come up with a more rational incentive than fear of after-life retribution. He may be an expert on that but his opinion on global warming is no more valid than yours, mine or Aunt Mabel's.-- angel, Aug 09 2006 random, halfbakery