A Space Elevator Would Make an Excellent Radiator

The Earth is getting hotter.

I don’t feel like having a heated (pun intended) argument over anthropomorphic climate change, so let’s just say for the sake of argument that in thirty year’s time a super-intelligent AI pops its metaphorical head out of a lab in Silicon Valley and turns the entire planet into a layered shell of computational material. Or that the price of Bitcoin goes to the moon, and humans do pretty much the same thing to our poor planet all on our own. Whatever: all of these things radiate a vast amount of heat, and the world will get hotter (especially if there’s a few extra gigatons of CO2 involved).

What do people usually do with things that generate a lot of heat? Well here’s an example, from a computer:

Harumphy at the English Wikipedia [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/)]
What we have here is a radiator, which is a way of moving heat from where it could blow things up, to where it simply melts your ice-cream. You can see similar things on cars (spectacularly so, on the back of certain hyper-cars).

Perhaps what we need is a radiator for the Earth.

This comes at a particularly good time in history. Material science has come a long way in the past few decades. There are new materials that are particularly good at, well, moving heat from one place to another.

One of those materials are carbon nanotubes (actually many forms of carbon are good at this). Nanotubes are, in fact, one of the best heat exchangers known. They have another attribute as well – they’re extremely strong, and can be used to build very long, very strong wires. In fact, they’re a prime candidate for building one of these:

Skyway and User:Booyabazooka [CC BY-SA 1.0 (https://creativecommons.org/licenses/by-sa/1.0)], via Wikimedia Commons
I assume that most of the people reading my blog are at least somewhat familiar with space elevators, at least conceptually. The idea is a very long wire, extending all the way out into space, to the point where its own weight acts as a counter-balance that holds it up. Then you can move people and cargo in elevators up and down it, instead of launching things with rockets. Some people also want to use them to conduct electricity that would be generated in space using solar panels down to the ground.

Which brings me to my point:

If you’re going to build one of these, and you’re going to build it out of a magnificently good thermal conductor, why not specifically engineer it to radiate heat from near the Earth’s surface, up, past all of the reflective layers of the Earth’s atmosphere, and out into space? It wouldn’t be too hard to build a large, flat radiator at the other end to beam all of the heat energy away from us (where it hopefully will not melt anyone’s ice-cream).