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Assume there is a giant steel (or any metal with good thermal conductivity coefficient) rod hanging from moon with its other end in atmosphere (say 5KM above sea level).

1.) Being the other end of rod is in space where it is really cold, will it help in any way to transfer the heat from the atmosphere to space?

2.) If so, can it be made more effective at slowing global warming?

3.) What other undesired consequences would it have?

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    $\begingroup$ I think such a rod (would require stronger material than steel) would actually ADD warmth because it travels through the atmosphere at very high speed, in excess of 400 meters per second. Friction will make it....burn up. $\endgroup$
    – Bookeater
    Aug 12, 2016 at 11:42
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    $\begingroup$ The Earth is 384,400 kilometers away from the moon. That means your theoretically-strong rod has a one-one-thousandth of a percent margin of error before plowing into the Earth - pretty sure the variation in orbit is more than that. $\endgroup$ Aug 12, 2016 at 22:59

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Metal on its own is not going to be enough - the problem with space travel is how to keep things cool as they heat up very quickly.

Conductive heat sucks when there is nothing to conduct to - you are reliant on radiation to cool; satellites use radiators that cycle ammonia.

If you plan on pumping stuff up and down to cool, I'd forget it; the amounts of material needed would be monumental and the energy required would need a lot of hand waving.

A way to reduce global warming from space would be a space shade; this reflects the sun's light before it hits the atmosphere.

edit: Also, a rod hanging into the atmosphere is going to be travelling at the speed the earth rotates (which is 1,036 mile an hour), so it would have to be something a lot stronger than steel to handle all that buffeting from the wind.

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Since you want something that is science-based, no such rod could exist, in the same way we cannot put a iron cable from space to Earth, it will just break under its own weight. Spider silk or colossal carbon nanotubes would be much better than steel as to regard strength/weight, but they are still not enough for that (see space elevator questions). Not to mention that Earth rotates around its own axis.

And no, it will not be able to pull heat out of atmosphere because the heat that is taken from thin air at low altitude, will be released in the atmosphere at higher altitudes (still because of air).

If you are looking for a good alternative for mass global warming reduction look at wind-turbines. Or to genetically modified vegetation. That would be a good alternative because you will re-use the wind energy.

Another alternative is to make the Earth's surface more reflective in order to reduce incoming radiation.

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Regarding "space is cold": That's not how space works.

There are three mechanisms which transfer heat: Conduction, Convection and Radiation. The vacuum of space offers neither conduction nor convection, so it is actually a thermal insulator and not a coolant medium.

Actually, the temperature of a perfect vacuum is undefined, because only mass has temperature. You can still talk about space being cold by measuring the temperature of individual particles which float around in near-earth space, and you might measure a quite low temperature. But there are not enough of these particles to cause any notable heat transfer from any larger objects they interact with.

The only way in which a body in space can lose heat is through eradiation, which doesn't depend on temperature.

I didn't do the math, but it is quite likely that the metal rod would gain more heat from being exposed to the sun than it would eradiate into space.

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  • $\begingroup$ +1, I would add that a body placed in a perfect vacuum without any incoming radiation will quickly radiate-away all thermal energy going towards absolute 0. If perfect vacuum really exists is another question :D $\endgroup$ Aug 12, 2016 at 16:09

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