3 ms·

Direct thermal forcing is at about 100mW/m^2. This gives us about a century to stop increasing energy usage and albedo. This is precisely where we were when pe

Direct thermal forcing is at about 100mW/m^2. This gives us about a century to stop increasing energy usage and albedo. This is precisely where we were when people first started raising alarm bells about greenhouse gases. The thermal emissivity of the night side of earth is only one of many limits we are running head first into. Almost all scarce resources, many abundant ones, and even abstract concepts like the growth of classical computation are all hitting limits where they only scale linearly or worse with energy input. Growing into the solar system is largely irrelevant because it's a constant increase vs an exponential and will not be meaningfully coupled to earth's economy without energy expendature on earth proportional to trade volume. And there's no compelling reason to hinge everything on the assumption that the second law of thermodynamics and speed of light are both false so nothing outside the solar system is relevant to those living inside it unless we overturn one or both first. All of this to avoid reexamining the blind faith assumption that we have to give an exponentially growing share of the pie to those who have the biggest share. Growth is only necessary for survival of the 99.99% if every year they give 2% of their wealth to the 0.01%

RandomLensman 4y ago
Once we build and make stuff truly not on earth it will decouple. The trade never reaches earth then, so overall human economy expands but not earth's (or only a little, ie high value trade, maybe even take some high waste energy processes off earth if energy from dropping product back is less). The human economy could be much larger but not all parts of the human sphere would necessarily trade with each other materially. Edit: "materially" in the sense of stuff. Some data from a nearby star could still be highly valuable, but exchanging stuff over lightyears might rarely be efficient.
- Schroedingersat 4y ago
  So then earth still has to degrow even for the short duration before the carrying capacity of the solar system gets exhausted. The presence or absence of a growing economy elsewhere is irrelevant. You ask why now? The answer is because we've already overshot the ability to do everything we do sustainably with the resources available. We need to get off the treadmill now and hope like hell technology and the available buffers are enough to limit the harm to 'merely' hundreds of millions dying.
  - RandomLensman 4y ago
    Definitely not degrowth, maybe low growth if high energy stuff cannot be moved off planet and results transported back with low heat impact. (Or no other ways of cooling are found). Also, for example, innovation from growing economies elsewhere can reach back to earth. Expensive stuff that relies on growth can continue to happen and the results shared. Carrying capacity of the solar system is huge, so quite some growth to be captured there. Once it is exhausted, growth for earth and the solar system might slow down because information will have significant travel time. And we haven't even exhausted earth and earth will become uninhabitable ultimately anyway so terminal sustainability is not truly needed.
    - Schroedingersat 4y ago
      Energy growth on earth must end this century. This entails growth in most primary industries also ending, as well as a large reduction in many. This is incompatible with a system where people starve and everything breaks whenever growth goes below 2%. "Stop giving everything to the people who already have stuff so we need the pie to grow at an exponential rate just to keep the share that goes to 99.99% of the world constant" isn't a hard concept.
Gatsky 4y ago
Can you explain what thermal forcing is in this context?
- Schroedingersat 4y ago
  The raw heat output of humanity divided by area of earth. GHG is bad because it produces single digit watts of forcing (captured solar heat that would otherwise escape). Direct thermal forcing from either capturing sunlight (making the surface darker) or emitting heat from nuclear derived (or in short term, fossil fuels before they run out) sources is just as catastrophic, but further off. We can happily replace our current energy needs with nuclear and renewable, but we're just back at square one if we don't end growth.

RandomLensman 4y ago

Once we build and make stuff truly not on earth it will decouple. The trade never reaches earth then, so overall human economy expands but not earth's (or only a little, ie high value trade, maybe even take some high waste energy processes off earth if energy from dropping product back is less). The human economy could be much larger but not all parts of the human sphere would necessarily trade with each other materially. Edit: "materially" in the sense of stuff. Some data from a nearby star could still be highly valuable, but exchanging stuff over lightyears might rarely be efficient.

Schroedingersat 4y ago
So then earth still has to degrow even for the short duration before the carrying capacity of the solar system gets exhausted. The presence or absence of a growing economy elsewhere is irrelevant. You ask why now? The answer is because we've already overshot the ability to do everything we do sustainably with the resources available. We need to get off the treadmill now and hope like hell technology and the available buffers are enough to limit the harm to 'merely' hundreds of millions dying.
- RandomLensman 4y ago
  Definitely not degrowth, maybe low growth if high energy stuff cannot be moved off planet and results transported back with low heat impact. (Or no other ways of cooling are found). Also, for example, innovation from growing economies elsewhere can reach back to earth. Expensive stuff that relies on growth can continue to happen and the results shared. Carrying capacity of the solar system is huge, so quite some growth to be captured there. Once it is exhausted, growth for earth and the solar system might slow down because information will have significant travel time. And we haven't even exhausted earth and earth will become uninhabitable ultimately anyway so terminal sustainability is not truly needed.
  - Schroedingersat 4y ago
    Energy growth on earth must end this century. This entails growth in most primary industries also ending, as well as a large reduction in many. This is incompatible with a system where people starve and everything breaks whenever growth goes below 2%. "Stop giving everything to the people who already have stuff so we need the pie to grow at an exponential rate just to keep the share that goes to 99.99% of the world constant" isn't a hard concept.

Gatsky 4y ago

Can you explain what thermal forcing is in this context?

Schroedingersat 4y ago
The raw heat output of humanity divided by area of earth. GHG is bad because it produces single digit watts of forcing (captured solar heat that would otherwise escape). Direct thermal forcing from either capturing sunlight (making the surface darker) or emitting heat from nuclear derived (or in short term, fossil fuels before they run out) sources is just as catastrophic, but further off. We can happily replace our current energy needs with nuclear and renewable, but we're just back at square one if we don't end growth.