Comments by "DynamicWorlds" (@dynamicworlds1) on "I recently learned that waste heat will boil the oceans in about 400 years." video.

Here's a big problem with that: any method of concentrating that waste heat is not only very costly in materials to build said systems, but it inevitably provides resistance to those devices dumping their waste heat as quickly as possible, which translates to inefficiency. Whether you're using peltier devices or a more traditional method of extracting energy from a heat differential (using fluids to drive electric motors in reverse), you're functionally creating an insulation system. The closest we can practically get to that in practical engineering terms is most likely just using heat pumps to pump waste heat into the ground the building is sitting on during the day/summer and drawing it back out during the night/winter. Really, though, the waste heat we generate is nothing compared to even a tiny change in the energy balance in how much energy is absorbed vs reflected from the sun. IF we're ever producing so much waste heat that it's more efficient to try and capture it than to try and reduce the energy absorption/retention of the planet, then we're talking about a situation where our energy production and usage is sufficient that we should be looking into moving people into O'Neal cylinders in space. (The point where it becomes a good idea to start living in space is when your energy usage and waste heat production is a bigger limiter on your economy than material availability) Assuming that our waste heat will continue to increase exponentially is a BIG assumption too. We know that the population is on track to level off and that we can in other ways should expect the waste heat per person to also eventually level off. We can't just look at current trends and assume they will continue indefinitely without evidence.
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Here's a big problem with that: any method of concentrating that waste heat is not only very costly in materials to build said systems, but it inevitably provides resistance to those devices dumping their waste heat as quickly as possible, which translates to inefficiency. Whether you're using peltier devices or a more traditional method of extracting energy from a heat differential (using fluids to drive electric motors in reverse), you're functionally creating an insulation system. The closest we can practically get to that in practical engineering terms is most likely just using heat pumps to pump waste heat into the ground the building is sitting on during the day/summer and drawing it back out during the night/winter. Really, though, the waste heat we generate is nothing compared to even a tiny change in the energy balance in how much energy is absorbed vs reflected from the sun. IF we're ever producing so much waste heat that it's more efficient to try and capture it than to try and reduce the energy absorption/retention of the planet, then we're talking about a situation where our energy production and usage is sufficient that we should be looking into moving people into O'Neal cylinders in space. (The point where it becomes a good idea to start living in space is when your energy usage and waste heat production is a bigger limiter on your economy than material availability) Assuming that our waste heat will continue to increase exponentially is a BIG assumption too. We know that the population is on track to level off and that we can in other ways should expect the waste heat per person to also eventually level off. We can't just look at current trends and assume they will continue indefinitely without evidence.
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