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> We (humanity worldwide) need to reduce greenhouse gas emissions by 99.9%. Citation needed.

ben_w 28d ago
IPCC. It is based on the mean lifetime of a CO2 pulse being order-of a thousand years, which is itself approximation of what IPCC says; actual decay rate behavious is not even as simple as exponential decay. At 1000 years exactly, steady-state requires 99.9% reduction in the long term. Good news is that in the short term, the higher partial pressure in the air means it leaves faster at first, so things stop getting worse much sooner than that.
- throw10920 28d ago
  > It is based on the mean lifetime of a CO2 pulse being order-of a thousand years, which is itself approximation of what IPCC says; actual decay rate behavious is not even as simple as exponential decay. > At 1000 years exactly, steady-state requires 99.9% reduction in the long term. So, that's ignoring carbon capture by means natural or artificial, and therefore is a totally irrelevant number, both to this conversation, and to most others.
  - ben_w 28d ago
    > So, that's ignoring carbon capture by means natural or artificial, and therefore is a totally irrelevant number, both to this conversation, and to most others. No, it inherently incorporates all natural processes that capture carbon. Artificial, sure, if you want to point at them I believe current effots might reduce the required reductions from 99.9% to 99.8%. However, I wrote "emissions", and the overwhelming majority of CCUS systems are reditecting what would otherwise be emissions directly to capture, i.e. what I wrote would include that as reducing "emissions".
    - throw10920 28d ago
      > No, it inherently incorporates all natural processes that capture carbon. It literally cannot, because it's not parameterized on the amount of additional plants being planted. > Artificial, sure, if you want to point at them I believe current effots might reduce the required reductions from 99.9% to 99.8%. Goalpost moving (i.e. fixing a particular value in hypothetical future assumptions that was not fixed or agreed-upon previously in order to support an otherwise-false point), which solidly sets the original claim as false. > However, I wrote "emissions", and the overwhelming majority of CCUS systems are reditecting what would otherwise be emissions directly to capture, i.e. what I wrote would include that as reducing "emissions". Technically compatible with your statement but not how the vast majority of individuals would interpret it as you originally wrote it. To be clear: I'm not arguing that we don't need to substantially reduce greenhouse gas emissions or that carbon capture is necessary. I'm arguing that last point, that "we need to reduce emissions by 99.9%" is extremely misleading and much more harmful than hurtful for those ends.
      - ben_w 27d ago
        > It literally cannot, because it's not parameterized on the amount of additional plants being planted. Primary production of the planet, i.e. total carbon fixation, is broadly not influenced in this manner. The things which do influence it, are included in the function. > Goalpost moving (i.e. fixing a particular value in hypothetical future assumptions that was not fixed or agreed-upon previously in order to support an otherwise-false point), which solidly sets the original claim as false. My point is that it is tiny in scale even at best. Furthermore, I claim it is unlikely to get meaningfully better than it already is, given the economics at present appear to be more "how do we game government objectives to get subsidies" rather than directly performing useful work that does not require subsidy. Perhaps I am too cynical, but typically if there's a good economic reason for doing something anyway, it's not in a list of big showy projects that might happen at some unspecified time in the future, it gets implemented by people who are happy to never get noticed. > Technically compatible with your statement but not how the vast majority of individuals would interpret it as you originally wrote it. Can you prove that? > To be clear: I'm not arguing that we don't need to substantially reduce greenhouse gas emissions or that carbon capture is necessary. I'm arguing that last point, that "we need to reduce emissions by 99.9%" is extremely misleading and much more harmful than hurtful for those ends. I do not accept your argument. Especially "much more harmful than [presumably auto-corrupt and you meant helpful]". *Net* emissions must go down approximately that scale. The common phrasing is "net zero" rather than "net 0.1%". However, your assertion that me missing the word "net" from "We (humanity worldwide) need to reduce greenhouse gas emissions by 99.9%" seems pedantic rather than helpful.

ben_w 28d ago

IPCC. It is based on the mean lifetime of a CO2 pulse being order-of a thousand years, which is itself approximation of what IPCC says; actual decay rate behavious is not even as simple as exponential decay. At 1000 years exactly, steady-state requires 99.9% reduction in the long term. Good news is that in the short term, the higher partial pressure in the air means it leaves faster at first, so things stop getting worse much sooner than that.

throw10920 28d ago
> It is based on the mean lifetime of a CO2 pulse being order-of a thousand years, which is itself approximation of what IPCC says; actual decay rate behavious is not even as simple as exponential decay. > At 1000 years exactly, steady-state requires 99.9% reduction in the long term. So, that's ignoring carbon capture by means natural or artificial, and therefore is a totally irrelevant number, both to this conversation, and to most others.
- ben_w 28d ago
  > So, that's ignoring carbon capture by means natural or artificial, and therefore is a totally irrelevant number, both to this conversation, and to most others. No, it inherently incorporates all natural processes that capture carbon. Artificial, sure, if you want to point at them I believe current effots might reduce the required reductions from 99.9% to 99.8%. However, I wrote "emissions", and the overwhelming majority of CCUS systems are reditecting what would otherwise be emissions directly to capture, i.e. what I wrote would include that as reducing "emissions".
  - throw10920 28d ago
    > No, it inherently incorporates all natural processes that capture carbon. It literally cannot, because it's not parameterized on the amount of additional plants being planted. > Artificial, sure, if you want to point at them I believe current effots might reduce the required reductions from 99.9% to 99.8%. Goalpost moving (i.e. fixing a particular value in hypothetical future assumptions that was not fixed or agreed-upon previously in order to support an otherwise-false point), which solidly sets the original claim as false. > However, I wrote "emissions", and the overwhelming majority of CCUS systems are reditecting what would otherwise be emissions directly to capture, i.e. what I wrote would include that as reducing "emissions". Technically compatible with your statement but not how the vast majority of individuals would interpret it as you originally wrote it. To be clear: I'm not arguing that we don't need to substantially reduce greenhouse gas emissions or that carbon capture is necessary. I'm arguing that last point, that "we need to reduce emissions by 99.9%" is extremely misleading and much more harmful than hurtful for those ends.
    - ben_w 27d ago
      > It literally cannot, because it's not parameterized on the amount of additional plants being planted. Primary production of the planet, i.e. total carbon fixation, is broadly not influenced in this manner. The things which do influence it, are included in the function. > Goalpost moving (i.e. fixing a particular value in hypothetical future assumptions that was not fixed or agreed-upon previously in order to support an otherwise-false point), which solidly sets the original claim as false. My point is that it is tiny in scale even at best. Furthermore, I claim it is unlikely to get meaningfully better than it already is, given the economics at present appear to be more "how do we game government objectives to get subsidies" rather than directly performing useful work that does not require subsidy. Perhaps I am too cynical, but typically if there's a good economic reason for doing something anyway, it's not in a list of big showy projects that might happen at some unspecified time in the future, it gets implemented by people who are happy to never get noticed. > Technically compatible with your statement but not how the vast majority of individuals would interpret it as you originally wrote it. Can you prove that? > To be clear: I'm not arguing that we don't need to substantially reduce greenhouse gas emissions or that carbon capture is necessary. I'm arguing that last point, that "we need to reduce emissions by 99.9%" is extremely misleading and much more harmful than hurtful for those ends. I do not accept your argument. Especially "much more harmful than [presumably auto-corrupt and you meant helpful]". *Net* emissions must go down approximately that scale. The common phrasing is "net zero" rather than "net 0.1%". However, your assertion that me missing the word "net" from "We (humanity worldwide) need to reduce greenhouse gas emissions by 99.9%" seems pedantic rather than helpful.