5 ms·

for reference, here's a look at what co2 emissions were 120 years ago ... https://skepticalscience.com/EmmissionsAcceleration.html https://skepticalscience.com/

for reference, here's a look at what co2 emissions were 120 years ago ... https://skepticalscience.com/EmmissionsAcceleration.html https://skepticalscience.com/EmmissionsAcceleration.html

HamburgerEmoji 5y ago
For more context, CO2 ppm was ~1000 less than 50m years ago.
q1w2 5y ago
Two things I find unsatisfactory in these data... 1. It doesn't touch on the Earth's natural absorption of CO2 - so we cannot conclude here that the additional CO2 emitted remains in the atmosphere (I mean we know that from other research, but this link is silent on that mitigation). 2. The cumulative numbers are pointless and misleading. CO2 is known to have a half-life on the order of under a century, so posting cumulative numbers gives the reader the misconception that the only way back is to extract CO2 from the atmosphere and that the situation is much more irreversible than it is in the long term.
- codingdave 5y ago
  CO2 has a half-life of 120 years, so it seems like a chart of data covering 120 years is appropriate.
  - q1w2 5y ago
    None of the charts seem to take into account any absorption at all, regardless of the duration. Having a chart 120 years long, and not including absorption, means all the numbers are significantly wrong. Also, 120 years is on the upper range of most estimates, and does not assume any increased absorption despite the fact that we've almost doubled the concentration of CO2.
- moffkalast 5y ago
  It's true, there is some absorption: https://www.eea.europa.eu/ims/ocean-acidification https://www.eea.europa.eu/ims/ocean-acidification and it's gonna make the situation so much worse it's hard to even imagine right now.
- shkkmo 5y ago
  I find the term "half-life" in this context misleading, possibly because I am coming from a nuclear science background where half lives are stable because they are the probabilistic result of nuclear decay. The chance of a given atom decaying doesn't change no mater how many you have or what you do. With CO2, the absorption probability is flexible and can depend on how much CO2 is in the atmosphere (as well as a large number of other factors.) To me this makes "half-life" a poor metaphor for CO2 absorption.
  - q1w2 5y ago
    Good point! The notion of half-life still works - but you are correct that the absorption is likely a product of the concentration. At any particular concentration, the half-life is still roughly representative. A differential equation would be more accurate, but it's not as easy to convey.
    - shkkmo 5y ago
      Actually what I am saying is that the absorption rate does not scale linearly with concentration / quantity. While increasing the quantity of CO2 in the atmosphere in many circumsyance will increase absorbtion, there is clearly an upper limit on how high that absorbtion rate can rise. In addition, the absorption rate also depends on how much has already been absorbed, ocean temperature, oceans currents, biosphere health and probably a number of factors of which I am unaware. The half-life of an unstable element is a fixed property of that kind of matter everwhere. The absorption rate of CO2 is in no way a property of CO2 itself, but rather a dynamic characteristic of the complex system that is the planet we live on. Instead of trying to break that down to a single number, I think we need to pay more attention to the actual mechanisms involved and the numbers behind them. CO2 gets sequestered into underground fossil duel deposits very slowly (and possibly not at all anymore given changes in the biosphere.) Vegetative matter is a very shallow reservoir that can only hold so much before the outgassing from decay wipes out the absorption from growth. The biggest source of absorption is (I believe) the oceans. We don't really know how much the ocean can absorb or how the global rise in tempuratures will effect that. I do think that you can't really view CO2 absorbed by the ocean as "gone" in the same way as with CO2 that is sequestered in fossil fuels. (or a decayed atom that has irreversibly become something else.)

for reference, here's a look at what co2 emissions were 120 years ago ... https://skepticalscience.com/EmmissionsAcceleration.html https://skepticalscience.com/EmmissionsAcceleration.html

HamburgerEmoji 5y ago

For more context, CO2 ppm was ~1000 less than 50m years ago.

q1w2 5y ago

Two things I find unsatisfactory in these data... 1. It doesn't touch on the Earth's natural absorption of CO2 - so we cannot conclude here that the additional CO2 emitted remains in the atmosphere (I mean we know that from other research, but this link is silent on that mitigation). 2. The cumulative numbers are pointless and misleading. CO2 is known to have a half-life on the order of under a century, so posting cumulative numbers gives the reader the misconception that the only way back is to extract CO2 from the atmosphere and that the situation is much more irreversible than it is in the long term.

codingdave 5y ago
CO2 has a half-life of 120 years, so it seems like a chart of data covering 120 years is appropriate.
- q1w2 5y ago
  None of the charts seem to take into account any absorption at all, regardless of the duration. Having a chart 120 years long, and not including absorption, means all the numbers are significantly wrong. Also, 120 years is on the upper range of most estimates, and does not assume any increased absorption despite the fact that we've almost doubled the concentration of CO2.
moffkalast 5y ago
It's true, there is some absorption: https://www.eea.europa.eu/ims/ocean-acidification https://www.eea.europa.eu/ims/ocean-acidification and it's gonna make the situation so much worse it's hard to even imagine right now.
shkkmo 5y ago
I find the term "half-life" in this context misleading, possibly because I am coming from a nuclear science background where half lives are stable because they are the probabilistic result of nuclear decay. The chance of a given atom decaying doesn't change no mater how many you have or what you do. With CO2, the absorption probability is flexible and can depend on how much CO2 is in the atmosphere (as well as a large number of other factors.) To me this makes "half-life" a poor metaphor for CO2 absorption.
- q1w2 5y ago
  Good point! The notion of half-life still works - but you are correct that the absorption is likely a product of the concentration. At any particular concentration, the half-life is still roughly representative. A differential equation would be more accurate, but it's not as easy to convey.
  - shkkmo 5y ago
    Actually what I am saying is that the absorption rate does not scale linearly with concentration / quantity. While increasing the quantity of CO2 in the atmosphere in many circumsyance will increase absorbtion, there is clearly an upper limit on how high that absorbtion rate can rise. In addition, the absorption rate also depends on how much has already been absorbed, ocean temperature, oceans currents, biosphere health and probably a number of factors of which I am unaware. The half-life of an unstable element is a fixed property of that kind of matter everwhere. The absorption rate of CO2 is in no way a property of CO2 itself, but rather a dynamic characteristic of the complex system that is the planet we live on. Instead of trying to break that down to a single number, I think we need to pay more attention to the actual mechanisms involved and the numbers behind them. CO2 gets sequestered into underground fossil duel deposits very slowly (and possibly not at all anymore given changes in the biosphere.) Vegetative matter is a very shallow reservoir that can only hold so much before the outgassing from decay wipes out the absorption from growth. The biggest source of absorption is (I believe) the oceans. We don't really know how much the ocean can absorb or how the global rise in tempuratures will effect that. I do think that you can't really view CO2 absorbed by the ocean as "gone" in the same way as with CO2 that is sequestered in fossil fuels. (or a decayed atom that has irreversibly become something else.)