Putting aside any debate about global warming, let's focus on what we could actually do about it. If we took broad patches of uninhabitable Earth and covered them with a reflective surface, such as metallic Mylar, it would presumably act like a giant mirror and reflect the Sun's energy back out into space, where it would dissipate harmlessly. It might not seem like it could produce much of an effect, but consider the fact that the increased albedo caused by jet contrails is responsible for a significant, or at least measurable, amount of cooling. So even a slight increase in albedo should, in theory, have some effect.
-- ytk, Nov 05 2011

Albedo supplement http://www.halfbake...Warming_3a_20Albedo
As 21Q observes, this concept is a popular one around here. It has a whole category. [bungston, Nov 05 2011]

White surfaces are better than shiny metallic for this purpose, as they have a low emissivity in the visible and near infrared, but high emissivity in the low temperature thermal infrared; in other words, they reflect most of the radiation from the sun while also efficiently radiating heat at earth's temperatures.
-- spidermother, Nov 05 2011


Gotta love these ideas; it's like "There's poison in the air, so the solution is to breathe less".

That being said, I've thought about painting the driveway black (or re-asphalting it), then whitewashing it every spring with just enough such that it turns black again as winter sets in.
-- FlyingToaster, Nov 05 2011


Large reflective surfaces on the face of the Earth would merely reflect solar energy back onto the upper atmosphere, not 'back out into space'. There is already a very large, very reflective uninhabited area of the Earth called Antarctica, and the last time I checked, there was a great big hole in the ozone layer directly over it. Coincidence?
-- Alterother, Nov 05 2011


Once is happenstance. Twice is coincidence. The third time it's enemy action.
-- mouseposture, Nov 05 2011


There are some very interesting crackpot theories involving that postulation as applied to the ozone hole, actually.
-- Alterother, Nov 05 2011


//Coincidence?// No, but correlation does not mean causation in this case. The lack of ozone production to replace that destroyed and the low temperature both result from the lower levels of sunlight.

Reflective surfaces do send radiation back into space. Some of it is absorbed, granted, but the atmosphere is just as transparent on the way out as on the way in.
-- spidermother, Nov 05 2011


Use some chemical - say, a solution of titanium dioxide.

Have the government spray it out of airplanes over cities, where it can be most effective (lightens asphalt).
-- lurch, Nov 05 2011


//Global warming is not necessarily a bad thing. You can't propose a solution to a problem that is not universally accepted as a problem without some debate pal.//

Of course I can—this is the Halfbakery. That said, I'm actually with you on this—I'm not convinced global warming is a problem either, never mind whether it's even happening or if it's anthropogenic in nature. I wasn't trying to dismiss the views of global warming skeptics, but rather to declare that I'm not necessarily in agreement with the "mainstream" thinking. Besides, everyone here gets to advance a really crackpot idea now and then, right?
-- ytk, Nov 06 2011


I think the accepted ratio is about 1 in 3, yes.
-- Alterother, Nov 06 2011


actually you could press little flats on the road surface so that all the light reflected a particular direction

then of course you coordinate the city pavers so that all the little angled flats at ceratain parts of town converge to create artificial convection thermals pulling cool air up n around the town
-- beanangel, Nov 18 2011



random, halfbakery