Future Current

J. Storrs Hall is the author of Nanofuture: What’s Next for Nanotechnology, a book covering the physical principles of engineering at the atomic scale, possible applications of nanomachines, and their potential alteration of human society. More recently he published Beyond AI: Creating the Conscience of the Machine, a review of the history of AI, discussing some of the major roadblocks that the field has recently overcome, and predicting the probable achievements in the near future. At October’s Global Catastrophic Risks conference in Mountain View he gave a presentation entitled “The Weather Machine” on the potential for nano-enabled “Climate Control for the Earth”

The following transcript of J. Storrs Hall’s GCR08 presentation “The Weather Machine: Nano-enabled Climate Control for the Earth” has not been approved by the speaker. Video and audio are also available.

The Weather Machine

I’m speaking with a futurist hat on here. I don’t want to imply that I’ve done a major, deep engineering analysis of what I am about to talk about, but I’ve done enough calculations that as a futurist I am fairly sure that something like this is within our next few decades.

The talk is going to be in three parts. First I am going to try and convince you that a certain kind of machine that I will describe is going to be possible, especially given the capabilities of molecular manufacturing that we just heard about. The second part is going to try to convince you that given that such a machine is possible that it is very likely to be built. In the third part, I am going to be talking about what the implications of that are, for global catastrophic risk and a few other things.

Here’s the machine. You build a little balloon—my guess is the balloon needs to be somewhere between a millimeter and a centimeter in size. It has a very thin shell of diamond, maybe just a nanometer thick. It’s round, and it has inside it an equatorial plane that is a mirror. If you squished it flat, you would only have a few nanometers thick of material. Although you could build a balloon out of materials that we build balloons out of now, it would not be economical for what I’m going to use it for.

Given that we can build these balloons so that the total amount of material in a balloon is actually very, very small, you inflate them with hydrogen in such a way that they will stabilize about twenty miles up in the stratosphere. So you have these itty bitty balloons, and inside of them they have a mirror. They also have a tiny little control unit and just barely enough power, fans, or other actuators to tilt themselves to a preferred orientation. Now you make enough of them to cover the entire globe.

This is why the nanotechnology makes a big difference, because if they are as thick as I have described them, you only need about ten million tons of material to do that. To compare that with the stuff that we are used to, that is about the same amount of material that is used to make a hundred miles of freeway. This is nothing that our technology cannot handle, assuming that you can actually turn it into a high-tech gadget of the kind I described.

So you have this balloon and it floats up there twenty miles. They all have a little GPS and receiver so they can turn themselves. That’s all there is to it. What can you do with a machine like this? The machine is essentially a programmable greenhouse gas. If you set the mirrors facing the sun, it reflects all the sunlight back. If you set them sideways, it allows the sunlight to come through, and similarly for the longwave radiation coming from the back side of the earth at night.

This machines, which I call “the weather machine,” has a radiative forcing capability. For comparison, the radiative forcing capability for CO2, as generally mentioned in the global warming theories, is about one watt per square meter. This machine essentially has a kilowatt per square meter of radiative forcing capability. It completely trumps any natural influence of that kind that’s out there or that we can imagine. If you are worried about our all dying because of global warming, or if you are one of the people who is worried about our all falling into an ice age, we can fix that.

The second version of this machine is actually even cooler. The first version is essentially like an existence proof of something that looks buildable with molecular manufacturing and will do the job. Version two: you have the same balloon, but inside of it you have a kind of aerogel that is switchable antenna units with crosslinks. You can tune the thing to be an absorber or transmitter of radiation in any desired frequency, in any desired direction (and if you’re really good, with any desired phase).

Once you get that, essentially you’ve turned this layer in the stratosphere into an enormous hologram. Of course, the astronomers really hate it, because it screws up viewing, but what they do love is that it turns the entire earth into a telescope with the aperture of 8,000 miles. Of course, you can take that light and change it into any other wavelength you want and send it off into any other direction you want. You can control not only the climate as a single parameter, but you can probably get close to controlling local weather. We don’t come close to knowing enough about the whole weather system to say exactly what you could and couldn’t do, but I am fairly sure that you could do things like make Canada as warm as California. You could cool the tropics, you could warm up the polar regions if you wanted to.

If you wanted to use solar power, for example, you could build an array of photovoltaics out in the desert out there somewhere and you could take the area of about a thousand square kilometers above it and set the little mirrors in the first version, or charge your little antennas in the second, to focus the sunlight down onto your area. Instead of having to have a thousand square kilometers of solar collectors, you have one. You have just concentrated all that sunlight on it and it’s pretty much free, because you have already built a device to control the weather. What’s more, you have not changed the energy balance any, because you are shading all the areas that are otherwise under the thousand square kilometers. That gives you in broad daylight an energy flux that is approximately the same as a thousand nuclear reactors of a typical size. Of course, you have to cool the collectors fairly vigorously because they are not 100% efficient.

That’s the machine. We have this gadget that can intercept the sunlight and do cute things with it. Part two: why do I think that it is fairly likely to be built, given that I think that it can be built? The first thing is global catastrophic risk. There are a lot of people that are worried about things like global warming. There are other people that are worried about ice ages. There are people who are worried about asteroids. In 2029 the asteroid Apophis is going to come within the orbit of the moon, passing the earth, and that is kind of going to be like a butterfly effect incident where it is fairly difficult to predict exactly what is going to happen to it after that close encounter. Our computers are good enough that once it gets close, we will be able to know pretty well.

In 2029, if this happens to be built by then, even the simple mirror version, as the asteroid comes tumbling past we can focus the entire earth’s worth of sunlight on it and give it a kick. This is probably a lot more appropriate in the case of Apophis than many other asteroids because it is going to be so close. A little tiny kick will have a huge result in 2036, when it comes back and might actually be hitting. A fairly minor kick in ‘29, hitting it with enough light to blow out some material, will probably be enough—if it is going to be in that resonance keyhole—to get it out.

That’s another catastrophic risk you could avert. The second reason to build it is that it is going to be extremely valuable. If you read the IPCC numbers on how much global warming is going to cost, what they actually estimate is that over the course of the century it is going to be about 3% of the global GDP. If you could actually control the climate and tailor it, you could make lots of places on the earth like Northern Canada and Russia as valuable as California. The effect on the global GDP would be enormous. There is a huge amount of value to being able to control the weather. This is something that people have always wanted to do and therefore, they probably will do.

Third, remember the power plant. What if it’s not a power plant underneath this thousand square kilometers of mirrors but the enemy ship, or some city you didn’t like? Another way of specifying the amount of energy that would get pumped into that area is the effect of exploding a one-kiloton atom bomb every second for as long as you wanted. You could steer it around and so forth. And if you can control the weather, you’re pretty much in charge. Anyone that doesn’t like you and starts rattling their sabers has twenty years of no summer, no growing season. It is a military engine second to none to be able to control the earth’s weather. For that reason alone, given the technological capability of doing it, it will be done.

Part three is actually the part I don’t know too well, which is the implications. The first thing is, I cannot see the US government seeing that this is possible and not doing it. It’s not in the nature of the beast. In fact, there are several other governments I cannot see believing it can be done and not doing it. If you are a smaller government that does not have enough conventional forces to defend yourself well while this is being put up, I’m guessing that approximately 5% of it is all you would need to have a setting that was a dead man switch. If they came and blew you up and you quit sending out the control signals, all of the little balloons went into snowball earth mode. It would be a doomsday device.

Once somebody gets 5% of one built, you’re stuck listening to them. Among other things, you can start building your own. In fact, it seems reasonable to imagine that by later in the century there are going to be several competing clouds of these things around. Hopefully they won’t end up physically competing with each other, but the people that are in charge of them will all come to some negotiation. That’s going to be all the more reason for someone wanting to be in the game. You have three billion balloons up, and I have seven billion, and this guy over there has two billion, which means we get that many votes in the weather control world government.

I can’t even come close to seeing all of the implications that this will have, but I’m fairly sure that it’s possible and that it will happen.

This entry was posted on Saturday, December 20th, 2008 at 4:59 pm and is filed under Nanotechnology, IEET events. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.