TL;DR

using/generating energy always emits heat as waste and there is an upper limit of efficiency that we are not that far from. if that energy was generated via something that is not a natural heat gradient for the earth’s surface there is a net increase of heat in the earth system simply by generating and using energy.

a lot of energy sources fall into this: fossil fuel, nuclear, geothermal, etc. two that don’t are (certain types of) solar and wind, since their energy would eventually be dissipated onto earth’s surface whether we intercept or not.

that waste heat is currently estimated to be ~2% of the heating power caused by global warming, so already significant. we essentially have an upper limit on sustainable energy usage on earth (and therefore an avg per person usage) or we will have Global Warming 2: Waste Heat Boogaloo.

  • niartenyawOP
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    1 year ago

    but the Earth surface is not a closed system. Life, an incredibly organized machine risen from just photosynthesis or chemosynthesis, is an exceptional example of entropy locally decreasing because of external influx of energy from the Sun and the center of the Earth.

    yeah, my understanding of this is the earth’s surface is generally at an energy equilibrium (combining sunlight, geothermal heat, dissipation to space, etc) which results in the current climate. adding energy to that system via heat changes that equilibrium.

    Secondly, he justly warned about gathering energy from outer space and importing in on Earth, something that I had never considered. But what if we used this energy in outer space as well? This seems like a good motivation for space colonization. That’s a (probably foolish) dream that could be compatible with exponential growth beyond what is available on Earth.

    wow this is an incredible idea! we could easily use all the energy we want in space or on another body that is less sensitive to heat (moon, mars, etc)