Hot Earth, Cold Earth: Dropping Some Science on Global Warming

I had a very interesting, student-led colloquia today about Global Warming in which the presenter addressed yesterday's announcement by NASA's Goddard Institute for Space Studies. The findings state that 2009 is tied for the second warmest year on record since 1880. Now year-to-year fluctuations are sometimes grounds for dismissal of evidence, but NASA debunks this claim by stating, "January 2000 to December 2009 was the warmest decade on record. Looking back to 1880, when modern scientific instrumentation became available to monitor temperatures precisely, a clear warming trend is present."

Interestingly enough, none of this information debates whether or not Global Warming is a man made trend; it simply doesn't matter. What does matter is that the adverse effects of a continual increase in average global temperatures are undebatable. Now science is often a scary subject for the average activist but, being a physicist, I'm going to give it to you anyway.

The Earth is constantly receiving 342 Watts/cubic meter of solar radiation (light). Only 107 Watts/cubic meter of light escape from Earth's atmosphere, due to an effective "barrier"of greenhouse gasses restricting its escape. The additional 235 Watts/cubic meter are being absorbed and re-emitted constantly within the atmosphere. For anyone who has studied a small amount of physics, conservation of energy demands that this extra energy must reach equilibrium within the system. This energy is released as heat radiation, and necessitates an increase in average global temperature. Again, none of this dwells on the debate as to the source of these greenhouse gasses; they are simply there or they aren't. Well, they're there. If you're having a hard time digesting the data, here's a diagram:



Now what are the possible solutions to a warming planet? The geoengineering groups have a few, very interesting, answers that I personally have never heard before. One school of thought is known as "Carbon Removal Techniques" or CRTs. An example of this would be placing a filter directly over smoke stacks that could remove greenhouse pollutants, without restricting efficiency, and would actually recycle some of the carbon to be facilitated for later use. This seems like a profitable endeavor to me, but why isn't it being employed?

One of the more radical tactics is SRM, or Solar Radiation Management. This includes painting the tops of buildings white to increase their reflectivity, thus allowing more solar radiation to escape. Some progressive scientists even endorse transforming (how?) deserts into reflective surfaces, thus locally cooling that area and reducing the average global temperature.

I think the most interesting of the proposed SRM solutions was to distribute football sized floating white surfaces across the world's oceans to increase the reflectivity of the majority of the Earth's largest surface (water). This would essentially erase any negative environmental outcomes (such as desert wildlife being destroyed from painting their ecosystem white). Now the cost-benefit analysis of such an immense oceanic project is a different story. It essentially will never happen. The speaker estimated that the covered area needed to reverse global temperature increases would be about 13 million square kilometers. Just to put this into perspective, the United States covers about 9 million square kilometers. This equates to distributing 2.5 billion such platforms and would cost an estimated $2,000 trillion. Ouch!

Another proposed solution would be what is known as "albedo modification." Albedo, for those who need an explanation, is a surfaces ability to reflect sunlight; rubber has poor albedo while snow has a large albedo. Cloud albedo modification would entail injecting salt into clouds to increase their droplet size, since a large water droplet obviously reflects more light than a small one. Again, this would increase the light escaping from the atmosphere and thus cool the planet. The Royal Society of London for the Improvement of Natural Knowledge, arguably the most respected scientific institution on the planet, prefers a slightly modified version of this. Known as Stratospheric Aerosol Distribution, this method of tackling temperature increase would involve introducing a relatively small, but extremely long-lived, amount of sulfur aerosol into the stratosphere. Such a solution would reflect the unwanted extra radiation away from the Earth before it could even reach the cloud level. This method seems to be reasonably cost effective, and can be implemented by current technology.

So, in essence, the debate as to what causes global warming is irrelevant. Simply, the Earth is warming, which is bad, and their are feasible solutions. What is a problem is that the US media seems to be hung up on the insignificant.