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That’s not evidence of global warming, you’d have to prove the energy released is large enough and not radiated away / stored back in some other way. Unfortuna

That’s not evidence of global warming, you’d have to prove the energy released is large enough and not radiated away / stored back in some other way. Unfortunately global warming is real and there’s plenty of evidence for it. Your mechanism isn’t really the issue though, it’s the greenhouse gases trapping new energy from the sun which is the basic root cause.

zyngaro 5y ago
Exactly what I was saying. Some of the those greenhouse gases is coming from fossil fuel combustion.
dTal 5y ago
It is interesting to consider just how much excess energy it would take to directly upset Earth's thermal balance. In 3001: The Final Odyssey, Arthur C Clarke predicted a thermal crisis caused by abundant free energy. Is it plausible? Total solar insolation is in the region of 1.8x10^17 W, which is some 10,000 times greater than the total energy use of humanity. This is not so far out when you consider our exponential energy use over the past few centuries! If growth does not slow (which it must), we could expect to use that much energy in about 4 more centuries. But we could expect to hit problems before then. What percentage of disruption to Earth's energy budget leads to visible effect? Our current imbalance due to greenhouse gases amounts to roughly 1 Watt per square meter, or 0.1%. At our current rate of growth we'll reach that in a mere century! So even if we switch entirely over to nuclear power starting today, and continue along our merry way safe in the knowledge that we're producing no greenhouse gases, in 100 years we'll have a similar warming problem from energy alone.
- eloff 5y ago
  Isaac Arthur on YouTube talks about this quite a bit. Given limitless cheap energy like nuclear fusion, the ultimate limit on human population is not land or water but the waste heat that we generate. We're very far from that being an issue today, but in some dystopian future where we turn earth into Coruscant, that could be a thing. I hope instead we stabilize our population or move to settlements in orbit. I'd like to see the land we currently use for food to be rewilded in a world where we can grow food in orbit and in vertical farms / artificial food factories. It would be nice if future humans mostly lived in cities or space habitats and the earth mostly went back to nature.
  - dTal 5y ago
    I don't know if 100 years is "very far". It's not implausible that someone develops a practical fusion plant this decade, and at that point we're well on our way. We don't even need to turn the planet into Coruscant - by the maths I just spelled out, we're only a factor of 10 away from noticeable warming! A bit more population growth, a few lifestyle upgrades for the global south, and we're there.
    - AngryData 5y ago
      Im skeptical that fusion will be a silver bullet for our problems. While I agree that producing lots of clean energy is the solution we need for many things, im not sure fusion is going to scale very easy when it is becomes practical for power generation. The sun is only producing thermal power per volume equivalent to a pile of manure, so even if we manage to increase that an order of magnitude, we will need an astronomical amount of plants and infrastructure to make it a primary energy source. And with such scales needed, we could have already done the same thing using other sources including fission.
      - dTal 5y ago
        Right, the point was simply to provide a plausible mechanism by which we could continue to increase our energy consumption exponentially, for the sake of argument. The thought experiment of "global warming from pure energy expenditure" doesn't work if the energy source is solar, because that energy offsets insolation. I'm not particularly bullish on fusion power, though we can dream.
    - eloff 5y ago
      Yes, that's closer than I thought. We may well need to deploy configurable sunshade at the earth - sun Lagrange point or something similarly drastic to keep the climate in a hospitable band.
  - jazzyjackson 5y ago
    You might be interested in the book “ethnobotany: people, plants, and culture” to learn why leaving nature alone is not the best option, that biodiversity and rich ecosystems can come from human interference - weeding plants that are taking over, spreading seeds of food and medicine, intentionally building the soil - after a few thousand years you end up with the Amazon rain forest. It doesn’t happen on its own, humans are a part of it. To have this mind of leaving earth alone and even leaving it behind is leaving a lot of good food on the table, I wouldn’t want to live among the factory farms in space.
- mdale 5y ago
  True .. but if we could just shoot excessive heat off into space no? Like a few city scale central heating / cooling systems that radiated into space.
  - dTal 5y ago
    Unfortunately not. All waste heat is already radiated into space, and there's no way to make it go faster. Heat always flows from hot places to cold places, unless you put energy in - so we can't gather all of our waste heat into one place for disposal, without creating more waste heat. It's the second law of thermodynamics, I'm afraid.
el_nahual 5y ago
Even though GP's mechanism doesn't explain global warming, it does explain the nigh-impossibility of developing technology that can carbon-capture us out of this mess. Biomass is basically solar-powered carbon sequestration. If each year of fossil fuel consumption corresponds to the energy of 400 years of biomass, and we've been burning "too many" fossil fuels for 50 years, then to get out of this mess we would have to cover 50x400 = 20,000 Earth's with solar panels hooked up to carbon capture machines. It's way worse, if course, because photosynthesis is more efficient than solar panels, and there's inefficiencies in carbon capture, but you get the idea! We've used up way, way, WAY too much energy making tiny explosions and now we have to undo each and every one of them.
- throwaway09223 5y ago
  Your example incorrectly assumes the entire solar constant went toward carbon sequestration and this is obviously not the case. The overall energy efficiency of the natural photosynthesis to sequestered carbon process is not inherently more efficient than man-made alternatives. The efficiency of the PV cell is just one small factor. A much more accurate way to calculate sequestration potentials is to measure their energy cost and multiply by available energy.
  - el_nahual 5y ago
    It's just a Fermi estimate. Feel free to multiply/divide by ten (or even 100!) in either direction. The main point is that we're not going to carbon capture our way out of this--at least not with anything resembling modern technology.
    - philipswood 5y ago
      I'd put my money on directly modulating incoming solar radiation instead From the first time I saw the animations of the planned Starlink fleet, I started wondering if one could use a satelite fleet to manage incoming solar radiation. I've commented about it a few times before. https://news.ycombinator.com/item?id=18474244 https://news.ycombinator.com/item?id=18474244

zyngaro 5y ago

Exactly what I was saying. Some of the those greenhouse gases is coming from fossil fuel combustion.

dTal 5y ago

It is interesting to consider just how much excess energy it would take to directly upset Earth's thermal balance. In 3001: The Final Odyssey, Arthur C Clarke predicted a thermal crisis caused by abundant free energy. Is it plausible? Total solar insolation is in the region of 1.8x10^17 W, which is some 10,000 times greater than the total energy use of humanity. This is not so far out when you consider our exponential energy use over the past few centuries! If growth does not slow (which it must), we could expect to use that much energy in about 4 more centuries. But we could expect to hit problems before then. What percentage of disruption to Earth's energy budget leads to visible effect? Our current imbalance due to greenhouse gases amounts to roughly 1 Watt per square meter, or 0.1%. At our current rate of growth we'll reach that in a mere century! So even if we switch entirely over to nuclear power starting today, and continue along our merry way safe in the knowledge that we're producing no greenhouse gases, in 100 years we'll have a similar warming problem from energy alone.

eloff 5y ago
Isaac Arthur on YouTube talks about this quite a bit. Given limitless cheap energy like nuclear fusion, the ultimate limit on human population is not land or water but the waste heat that we generate. We're very far from that being an issue today, but in some dystopian future where we turn earth into Coruscant, that could be a thing. I hope instead we stabilize our population or move to settlements in orbit. I'd like to see the land we currently use for food to be rewilded in a world where we can grow food in orbit and in vertical farms / artificial food factories. It would be nice if future humans mostly lived in cities or space habitats and the earth mostly went back to nature.
- dTal 5y ago
  I don't know if 100 years is "very far". It's not implausible that someone develops a practical fusion plant this decade, and at that point we're well on our way. We don't even need to turn the planet into Coruscant - by the maths I just spelled out, we're only a factor of 10 away from noticeable warming! A bit more population growth, a few lifestyle upgrades for the global south, and we're there.
  - AngryData 5y ago
    Im skeptical that fusion will be a silver bullet for our problems. While I agree that producing lots of clean energy is the solution we need for many things, im not sure fusion is going to scale very easy when it is becomes practical for power generation. The sun is only producing thermal power per volume equivalent to a pile of manure, so even if we manage to increase that an order of magnitude, we will need an astronomical amount of plants and infrastructure to make it a primary energy source. And with such scales needed, we could have already done the same thing using other sources including fission.
    - dTal 5y ago
      Right, the point was simply to provide a plausible mechanism by which we could continue to increase our energy consumption exponentially, for the sake of argument. The thought experiment of "global warming from pure energy expenditure" doesn't work if the energy source is solar, because that energy offsets insolation. I'm not particularly bullish on fusion power, though we can dream.
  - eloff 5y ago
    Yes, that's closer than I thought. We may well need to deploy configurable sunshade at the earth - sun Lagrange point or something similarly drastic to keep the climate in a hospitable band.
- jazzyjackson 5y ago
  You might be interested in the book “ethnobotany: people, plants, and culture” to learn why leaving nature alone is not the best option, that biodiversity and rich ecosystems can come from human interference - weeding plants that are taking over, spreading seeds of food and medicine, intentionally building the soil - after a few thousand years you end up with the Amazon rain forest. It doesn’t happen on its own, humans are a part of it. To have this mind of leaving earth alone and even leaving it behind is leaving a lot of good food on the table, I wouldn’t want to live among the factory farms in space.
mdale 5y ago
True .. but if we could just shoot excessive heat off into space no? Like a few city scale central heating / cooling systems that radiated into space.
- dTal 5y ago
  Unfortunately not. All waste heat is already radiated into space, and there's no way to make it go faster. Heat always flows from hot places to cold places, unless you put energy in - so we can't gather all of our waste heat into one place for disposal, without creating more waste heat. It's the second law of thermodynamics, I'm afraid.

el_nahual 5y ago

Even though GP's mechanism doesn't explain global warming, it does explain the nigh-impossibility of developing technology that can carbon-capture us out of this mess. Biomass is basically solar-powered carbon sequestration. If each year of fossil fuel consumption corresponds to the energy of 400 years of biomass, and we've been burning "too many" fossil fuels for 50 years, then to get out of this mess we would have to cover 50x400 = 20,000 Earth's with solar panels hooked up to carbon capture machines. It's way worse, if course, because photosynthesis is more efficient than solar panels, and there's inefficiencies in carbon capture, but you get the idea! We've used up way, way, WAY too much energy making tiny explosions and now we have to undo each and every one of them.

throwaway09223 5y ago
Your example incorrectly assumes the entire solar constant went toward carbon sequestration and this is obviously not the case. The overall energy efficiency of the natural photosynthesis to sequestered carbon process is not inherently more efficient than man-made alternatives. The efficiency of the PV cell is just one small factor. A much more accurate way to calculate sequestration potentials is to measure their energy cost and multiply by available energy.
- el_nahual 5y ago
  It's just a Fermi estimate. Feel free to multiply/divide by ten (or even 100!) in either direction. The main point is that we're not going to carbon capture our way out of this--at least not with anything resembling modern technology.
  - philipswood 5y ago
    I'd put my money on directly modulating incoming solar radiation instead From the first time I saw the animations of the planned Starlink fleet, I started wondering if one could use a satelite fleet to manage incoming solar radiation. I've commented about it a few times before. https://news.ycombinator.com/item?id=18474244 https://news.ycombinator.com/item?id=18474244