Stop Worrying - Buy that swamp land in Florida - NOW!
The gist of Professor Greg Benford's talk at the Patrick Henry Democratic Club in the OC this May of '06 was virtually orthogonal to what he said at the Orange County Science Fiction Club's meeting about a year ago. At that meeting, he gave us the full-scope analysis/overview of the problem, with the Power Point slides, etc., and it didn't sound hopeful at all, with NONE of the proposed solutions really making a dent in the final apocalyptic outcome for the planet, taken separately or all together.
The only solution that Gregg posited that would actually work - in the opinion of the major scientific panels that had studied the matter - was to put an enormous (size of continental U.S.) fresnel lens in the La Grange point between the Earth and Sun, taking at least 20 years to build and 6 trillion bucks. (I suggested blasting dust off the moon into trajectories calculated to block solar radiation, which Dr. Benford said had not been considered.)
So, to my vast shock, this time Gregg did an about face, informing us that the problem is basically solved. All we have to do is inject a large amount of very tiny reflective particles into the Stratosphere, i.e., about 20 miles up. The particles would be small enough to be invisable to the naked eye - much smaller than the wavelength of visible light - but highly reflective of UV. Since UV photons carry energy vastly disproportional to their numbers, selectively blocking the UV would reduce skin cancer and improve crop yields while also cutting the energy absorption enough to offset the CO2/Methane blanket.
Global warming would still occur in some areas, but overall the effect of high CO2 but reduced overall solar energy input would be to even out night/day temperature cycles while keeping the average temperature about the same. The energy that drives hurricanes and typhoons would also be significantly reduced, as storms in general depend largely upon temperature differences for power. So far, so good, for the majority of the planet, although some areas will doubtless see their weather get worse.
How much will it cost? Assuming that the current estimates and evidence hold up, about $1 Billion per 5 year period, according to Greg. (The stuff stays in the Stratosphere for about five years.) Using large fixed cannons or rail guns for launching the dust might cut that figure even more, but the bottom line is that Israel could afford to do it if it got tired of the increasingly scorching summers there. So could Iran. Or the majority of significant nations of the Earth. So, someone willalmost certainly do it, once the word gets out.
Possibly India. They're up against an enormous problem of Bangladesh flooding permanently if global warming continues as projected, as well as the typhoons strengthening to something really nasty. If they could actually CUT temperatures by a couple degrees over India, while saving Bangladesh, you don't think they wouldn't JUMP for it? Actually, though, once the experimental verification comes in and the world scientific community comes on board, I would expect it to become a U.N. job. After all, it will effect weather globally, just as CO2/Methane emissions already are.
Ecological impact of the dust will be virtually zero, insofaras pollution from the particles is concerned. The total volume would be many orders of magnitude less than what we're already dumping into the atmosphere, and the particles, besides being non-toxic chemically, would also be so small as to pass right through the body and out via the kidneys. There really doesn't appear to be any significant downside, although Benford insisted that a lot of careful testing should precede any actual deployment.
You heard it here.
I don't want to dilute the above with less vital news, but there are other things that Greg mentioned that would help, and we're already doing some of them. As he mentioned a year prior at the Orange County Science Fiction Club, Mediteranean countries have long dealt with local solar heating by making all their buildings white, including the roofs, thus reflecting the energy back out into space. Los Angeles has a commission of some kind that is actively promoting this, and we may expect some kind of tax incentive (or penalty) to come along soon.
There are also fairly cheap and easy ways to lighten up pavements without sacrificing durability or other wanted qualities. The net effect of reflecting more energy would be a significant drop in local peak temperatures, which - like the unfortunate multiplier effects of global warming - would have a multiplier effect in reducing the amount of air-conditioning in use. Air conditioners are nowhere close to perfect, for those of my readers who don't have physics degrees.
Even if they were perfect, they would still only be moving the heat from inside to outside. In fact, however, they are necessarily less than 50% efficient. So, as you cool down your office, house or car, you simultaneously heat up the outside by more than twice as much, in addition to the fuel that has to be burned. So, any reduction in the need for air-conditioning can be multiplied by three or so in terms of net environmental impact.
Of course, all that cooling from white roofs, etc. is not so desireable in the winter, when we might end up burning more fossil fuels to stay warm. So, who has the plans for a simple roof covering that can be removed, or perhaps reversed - as in, white on one side, black on the other? While none of this is nearly enough to halt global warming, it can have a major local impact, particularly in cities, reducing pollution from the extra gas burned to run air-conditioning, if nothing else.
Another possibility that occurs to me is that of changing the oceanic albedo (reflectance). The oceans are very effective absorbers of solar energy. Just look at any satellite photo. Notice how dark the oceans are, and that they cover most of the earth's surface. Gregg mentioned this in passing, but didn't suggest doing anything about it. However, it might actually be cheaper to put floating reflectors out in the deep ocean than blasting thousands of tons of dust into the stratosphere. It wouldn't help us with the UV, but we've survived UV for ages, so that's just a bonus effect anyway.
Whatever we used for reflectors on the water would be carried with the currents, of course, so we would have to plan on scooping them up and returning them to GO on an ongoing basis. We wouldn't have to cover the entire ocean, by a long shot, as it is the largest solar heater on the planet, by far. Perhaps only a fraction of the ocean would be required, and keeping that in the deep ocean would have minimal impact on sea life, as the deep ocean is pretty much a desert.
My first thought for this was little plastic circles, much like jar lids. If the lids were also impregnated with trace minerals on the bottoms, then they could also attract algea, which would mean oxygen generation and a food source for the rest of the chain of life... The reason that the deep ocean is such a desert, after all, is because there is a lack of the trace minerals that coastal runoffs constantly replace closer to land. Alternatively, because plastic generally comes from oil - although it can be manufactured from any organic source - I thought about silicon or glass, as in hollow glass or ceramic beads or saucers, also impregnated on the bottom to promote sea life.
Just a thought..