Environment

Could changing the color of the sky to counter global warming backfire?

The world's largest solar power facility, located near Kramer Junction, California, consists of five Solar Electric Generating Stations and covers more than 1,000 acres.
The world's largest solar power facility, located near Kramer Junction, California, consists of five Solar Electric Generating Stations and covers more than 1,000 acres.

The concept of delaying global warming by adding particles into the upper atmosphere to cool the climate could unintentionally reduce peak electricity generated by large solar power plants by as much as one-fifth, according to a new study by the National Oceanic and Atmospheric Administration (NOAA).

The problem

Global warming is one of the most important long-term issues that we have to deal with as a world today. We have pumped excess carbon dioxide into the atmosphere, which serves as an insulating blanket of air causing the world to trap more heat from the sun, and therefore increases the temperature globally. Our main approach to combating the warming of the earth is to reduce the amount of carbon we pump into the air in an attempt to keep atmospheric levels of carbon in control. However, some scientists feel that this reactive solution does not adequately combat climate change and the increasingly dire predictions emerging about the speed of its impact.

The last resort solution

One radical solution as proposed by scientists like Australia's Tim Flannery has proposed a radical alternative as a last resort solution: pump materials such as sulphur into the upper atmosphere in an attempt to block out a portion of the sun's rays, forming a giant human created blanket over the ozone layer. This would prevent the full amount of solar heat entering our atmosphere in the first place, and in turn lower the amount of carbon dioxide being trapped. One of the side-effects of this method would be that the sky would change color, taking on a deep purple hue, rather than the familiar sky blue that we know and love today.

The advantages of this approach is that it would allow us, as a race, to continue our technological expansion. It would lessen the urgency to cut back on our carbon emissions on which our society has evolved to depend.

There have been naturally occurring instances of such high atmospheric seeding. In 1991 Mt. Pinatubo erupted, spewing 20 million tons of sulfur dioxide into the atmosphere. This left a sulfuric acid haze over the world, which caused global temperatures to drop by about 0.9 degrees F (0.5C).

The problem with the last resort solution

However, such a strategy is not without its share of disadvantages. Daniel Murphy, a scientist from the National Oceanic and Atmospheric Administration (NOAA) Earth System Research Laboratory, has been researching one of the possible implications of such a geo-engineering project. While such atmospheric modifications would only be expected to deflect about 3 percent of the sunlight incident on the earth, Murphy has found that solar energy collectors would face a reduction of up to one-fifth of the usable energy that they collect presently. Even though 97 percent of the sun's light will make it through the Earth's modified stratosphere, much of it will be scattered, making the light diffuse. Diffuse light cannot be focused in the same manner that direct light can be, which lessens its usability in most optical systems. Almost all projects that harness solar energy require a large portion direct sunlight that can be focused and concentrated on a cell of some kind.

"The sensitivity of concentrating solar systems to stratospheric particles may seem surprising,” said Murphy. “But because these systems use only direct sunlight, increasing stratospheric particles has a disproportionately large effect on them.”

Murphy compared these predictions to output data from Solar Electric Generating Stations. After the 1991 eruption and found they lined up perfectly, supporting his prediction that there would be a 20% loss in usable solar power.

Locally and internationally solar energy is both viable and popular. As one of the most promising sources of alternative energy it is expected to play a large part in decreasing our reliance on fossil fuels. If we compromise the usefulness of this energy source in order to cool the atmosphere, we may end up using more fossil fuels which would result in pumping more carbon into the atmosphere to compensate for the lack of solar power. This may end with us leaving graffiti on the sky and not improving our situation with global warming.

Stephen Saunders

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4 comments
hughmama
Highlander 2 anyone?
Nantha Nithiahnanthan
Cutting out sunlight to reduce global warming will not only affect the small amount of slaor electricity generated, it will, more importantly lead to less amounts of light received by greenery for photosynthesis. It will be a big disaster as it will be worse than deforestation as habitats for flora & fauna are changed. Dumb idea.
It would be better to reflect heat back into the atmosphere where ther is no forest cover. This way we can better control the areas from which we reflect heat back from. Which is why the better solution, overall, is to increase solar panel use.
Burnerjack
Um, I might be confused BUT, wasn\'t the Earth WARMER like when the dinosaurs ruled the Earth? As the Earth warms, doesn\'t it enable greater agricultural output?
If all the carbon fuels cease being utilized today were to stop tomorrow morning, what would the effect be?
I just can\'t help get the feeling that this AGW is a gimmick to sell the alternative fuel market at a higher price that would be otherwise.
I do Emphatically believe that with power comes responsibility and proper husbandry over the Earth is a moral obligation.
Its kinda funny, I think Time or Newsweek Magazine had a cover illustration entitled \"Snowball Earth?\" They were afraid in the early 70s (?) of DROPPING global temps. Not being a scientist or trying to sound like one, the Earth seems to have been losing solar reflective surface (albedo) since the recession of the grate ice sheets. Less ice, more green/brown surface=more solar energy absorption. Higher mean temps.
Of course, if you subscribe to this, you will be branded an ecological heretic.
JarrodB
To that \'\'interesting\'\' scientist, Tim Flannery, from AustraliaThere\'s a couple of things I\'d like to say:First, I\'m willing to admit this idea does have some benefits. However, don\'t overlook the fact that sulphur dioxide mixes with water under certain circumstances to make sulphuric acid. We all know acid rain is not good. Acid rain is made up of sulphuric acid, hydrogen bicarbonate, and nitric acid. Second, regardless of your merit as a scientist, how are everyday people who know science or not supposed to trust the people of which these ideas are derived? Just because something in nature happens doesn\'t automatically give people a right to replicate it. (in your case sulphur dioxide, among other things) In case you need to know why nature acts sort of funny, just remember what Lechatelier said, which was close to every action has a reaction. So basically, nature is always to trying to level out. Third, I wonder if there\'s an ethics class or programme in laboratories and science institutions throughout the world to prevent people from taking risky and pidantic choices that could severly harm and/or damage the planet.