Wednesday, November 15, 2006

A Giant Sunbrella

Do you ever stop and ask yourself, "What if all the climate prophets-of-doom are right?" What if all the worst fears about global warming come to pass and the world is threatened with killer temperatures, droughts, floods, and all the other scenarios that would make this time of partisan politics and the global War on Terror look like the good old days? One possibility, of course, is that a whole lot of humans would die off, and if people and their greenhouse gas-producing ways really are the root cause, then the Earth would balance itself out again with less pesky humans to mess things up. It could be, though, that humans aren't the culprits. It entirely possible that cosmic rays affect our climate, and phytoplankton could play their role, as well. Theories, theories, everywhere. Whether humans are the cause, or natural phenomenon over which we have no control, if the climate does warm up significantly (and I do believe that the words if and significantly are pretty important here), we might want to come up with some options to keep ourselves from becoming barbecue.

This is where the "smart people" enter the picture. NASA's Earth Observatory reports that University of Arizona astronomer Roger Angel has come up with a plan, a sort of emergency cooling system for the planet, which won him and his colleagues a NASA Institute for Advanced Concepts grant. The grant will be used to further study the possibility of sending trillions of small spacecraft up into orbit, to form a giant cloud that would act as a sunshade, diverting a portion of the Sun's rays away from the Earth:

The spacecraft would form a long, cylindrical cloud with a diameter about half that of Earth, and about 10 times longer. About 10 percent of the sunlight passing through the 60,000-mile length of the cloud, pointing lengthwise between the Earth and the sun, would be diverted away from our planet. The effect would be to uniformly reduce sunlight by about 2 percent over the entire planet, enough to balance the heating of a doubling of atmospheric carbon dioxide in Earth's atmosphere.
One cannot fault the scientific community for lacking ambition, wouldn't you agree? Angel has the specs all worked out for composition, steering and delivery, and if the plan flies "as is," with all the current concepts intact, it will only cost about $100 billion a year to turn on the global air conditioning, "about two-tenths of one percent of the global domestic product." It sounds as if, were the Earth in such dire straits that implementation of emergency plans became necessary, the world's economy could afford to pony up that much, especially if the alternative was going to be factor 2,000 sunscreen, and/or a return to a pre-Industrial Revolution way of life.

In "science time" it wouldn't even take too long to pull the shades, once we were sufficiently motivated. According to NASA, it would only take about ten years to deploy all the flyers necessary for the job, if they can get the twenty electromagnetic launchers up and running that they would need to send the little life-savers into position. Twenty-five years could see the whole project developed and installed, and with a useful life of approximately fifty years, we'd only have to replace it once or twice a century for the duration of the heat wave. How's that for value, huh? Your average patio umbrella certainly doesn't last that long. Of course, your average patio umbrella doesn't cost $100 billion a year, either.

It's kinda comforting to know that whether or not all our technology is the cause of the potential climate crisis that's got the world in a dither, all our technology may also be the thing that saves the day. Wouldn't it be amazingly sci fi if we did end up with the equivalent of a giant parasol keeping the Earth's head cool? Mind you, since the global warming and cooling fears trade off every few decades, in a few years time we're going to be hearing about scientists who are figuring out ways to catch a few extra rays from the Sun, amplify them, and turn on the equivalent of a global heat lamp. Either way, it will be scientists who come up with the schemes to save mankind. Smart people are so useful.