could this help with global warming?

Question

if i coverd the area if water around the artic with a reflective surface ie a mirror would it cut down the heat the earth absorbs

Answer 1

Yes it could and similar schemes have already been considered - both using mirrors on Earth and placing them in space.

There are problems locating mirrors on Earth, because of the way the planet revolves it's in darkness half the time so any solution involving mirrors has a maximum of 50% efficiency.

When it's daylight it can be cloudy, further reducing the effectiveness of mirrors. During early morning and evening the sun is low on the horizon and the amount of sunlight (solar radiation) reaching Earth's surface is low.

Because of these and other factors the efficiency of the mirrors is likely to be about 20 to 25% of the maximum.

Add in that the atmosphere difuses sunlight, more solar radiation can be reflected from space than from Earth, if they're wet following rain the sunlight will be refracted in all directions, to be effective they would need to track the sun's progress through the sky and this would require huge amounts of power to drive the massive machinery needed. The efficiency is now reduced to perhaps 15%.

The scientists who researched the space mirrors idea came up with a figure of 100,000 square km. This is a huge object to construct in space, one advantage of being in space is that there's no weather and if it's constructed at the L1 point there's no gravity either (this is the point 1.5 million miles from Earth where the sun's gravity balances that of Earth).

The mirror could be exceptionally lightweight, a similar scheme to construct a sunshade in space would use large glass discs each weighing just 1 gramme and complete with onborad computer and solar powered solar-sails to point the discs toward the sun.

At 1 gramme a piece, a rocket designed to carry a heavy payload could carry perhaps 100 million 'mirror panels' at a time (the Shuttle could carry 23 million). 100 rockets, 100 million panels a time, 10 sqaure metres per panel and you have your 100,000 square km solar mirror.

More info...
http://www.nytimes.com/2006/06/27/science/earth/27cool.html?ex=1309060800&en=d0d351a5cf6b48d1&ei=5088&partner=rssnyt&emc=rss
http://news.bbc.co.uk/1/shared/spl/hi/picture_gallery/07/programmes_global_sunshade/html/1.stm

Answer 2

Covered the area around the arctic with a reflective surface? Well how about we fix this global warming problem by reducing the emissions of greenhouse gases. That way there will be a reflective surface around the arctic to help cool the planet. It's called ice.
http://www.windows.ucar.edu/tour/link=/earth/albedo.html

Answer 3

Hypothetically, yes.

But from a practicality issue, this is simply not feasible. The resources and energy needed to create, deploy and maintain the surface (mylar would probably be the cheapest) is not worth the small contribution it would make.

In addition you should consider these points:

Most of the heat melting Arctic ice are warm ocean currents from the south. A reflective surface would do nothing to stop this flow. Ice would continue to melt. And manipulation of the ocean currents (part of the global thermohaline circulation) should be considered untouchable until we know more about it.

Unless you remove the root cause of global climate change you really have only performed a "band-aid" fix. Whether or not you believe in man-made global warming, your solution doesn't address what is causing the warming in the first place.

Keep using your imagination.

Answer 4

In theory, this works a little. But, we would be better off putting the reflective material over darker colored areas. The Artic is essentially white and already reflects heat.

Answer 5

Global warming is mostly occuring because man is messing around with climate. That is threatening huge problems. It's basically a very large uncontrolled experiment.

It doesn't seem correct to try to fix that by messing with the climate some more, trying to oppose the first problem. More uncontrolled experiment. The results are hard to predict.

Instead we need to turn control of climate back over to nature. Until recently, climate had been pretty stable for the last 2000 years.

The main way to do that is to reduce our use of fossil fuels, which is a good idea for many reasons.

Answer 6

Not sure about this one. I know they have thought have ways to reduce global warming. Ways that seem kind of far out such as "artificial trees" to collect CO2 in the atmosphere, or deploying shields above earth which could be similar to your idea, or even catching some of it, freezing it, and dumping it into the ocean. These are all ideas that seem very farfetched and probably all have their own bad effects too so really our only help with it is the effort of each individual

Answer 7

What if it gets out of hand and causes global cooling? Think of all the extra energy that will be used to keep everyone warm in a new ice age. And all the farm land covered by snow and ice. No food.

Answer 8

That is a very nice solution. Keep thinking. And in this way we can solve the global warming problem if everyone thinks like you and try to find a solution.

Answer 9

I think the mirrors would work better in space between the sun and the earth.

Answer 10

OMG!!! GLOBAL WARMING IN NOT TRUE!!!!!!!!! I MEAN THOUSANDS OF YEARS AGO THE HEAT TEMPERATURE WAS LIKE 8 DEGREES HIGHER AND IT DIDN'T EVEN MELT GREENLAND!!!!!!! GLOBAL WARMING IS STUPID!!!!! if you believe in it then ok but just to tell you this whole global warming thing is out of wack...