If and when we get to that point various theoretical methods are available for bleeding off surplus heat; one of them is aiming a neutron beam at the moon. One upside of all this learning the hard way via profligate energy generation and accidental geoengineering taking place since the industrial revolution is that it opens the door to possibilities of regulating the impact of Milankovitch cycles on our civilization and biosphere.

If you can concentrate energy, eg into a neutron beam, then it's not waste heat. It's a form of energy you still can get useful energy out of.

The only thing you can do with true waste heat on the scale of earth is to radiate it into space.

You might want to look into eg https://en.wikipedia.org/wiki/Second_law_of_thermodynamics

My comment was written with precisely the second law of thermodynamics in mind. If you’re generating energy at a rate greater than you have a use for, to the point that you have a problem, yet also able to harvest it, then you want to radiate it back into space, yes. Neutron beams would be a cool, perhaps fanciful yet potentially practical way of doing that in a concentrated manner.

Either I completely misunderstand you, or you don't understand thermodynamics at all.

Do you know how the Carnot cycle works, and more importantly, why no process to generate electricity from heat can be more efficient?

> If you’re generating energy at a rate greater than you have a use for,

Huh? Why would anyone do this? Just turn off the excess capacity.

(Do keep in mind that when we produce electricity, we necessarily have waste heat. That waste heat has energy, but it's not energy we can use.)

Any kind of heat engine essentially works like a water wheel: you take heat from a high temperature source (water from a source at big height), you send it through your apparatus, and out comes heat at a lower temperature (water at a lower height) on one side, and some electricity on the other.

> ... then you want to radiate it back into space, yes. Neutron beams would be a cool, perhaps fanciful yet potentially practical way of doing that in a concentrated manner.

Huh? If you can concentrate the waste energy, it's not waste heat. You'd want to use it instead of just bleeding it into space. Do you understand that?

You'd use that concentrated form to run another engine.