Good read :) now feel like Ⅰ have a grasp on why SAI perhaps Sucks where Ⅰ basically knew nothing prior to reading beyond "SAI is when aerosols into the atmosphere because reflects some frequency of light which might cool things down".
I also find myself surprised that the numbers are close enough for a factor of 2 cost increase to actually change the overall cost/benefit conclusion! I wonder if nonlinearities in costs of global warming (and possibly in the consequences of sulphur injection) mean that smaller SAI passes cost-benefit while larger ones don't?
I'm not an economist, but how it was explained to me was: if a carbon credit (or similar) for SAI is sufficiently cheaper than a carbon credit for something like carbon capture that it makes it worth the consequences, then SAI works from an economic perspective. While SAI is cheap to do sure, the carbon credit would probably end up being less value than one for a different solution.
This makes it so a factor-of-two increase in the amount of sulfur you need much more expensive, because the scaling factor of the cost of a "carbon credit" would have to be based on bulk sulfur emissions since this is how you factor in the adverse consequences.
Ah, so we're talking about whether it's more viable than other ways of mitigating extant greenhouse gases, not whether it's more or less expensive than the effect of doing nothing. That makes the numbers make more sense to me, thanks :)
The precipitation rate reduction happens due to the interaction of sulfur aerosol with clouds when it descends - a tropospheric process. If the aerosol is injected into the stratosphere then exactly where this happens is very hard to predict since it is dependent on a combination of synoptic scale and local scale processes, which couple together. The residence time of the particles also goes beyond the reasonable prediction range of most initial condition based models.
This makes it effectively random where the aerosol descends, and how spread out it is, leading to the appearance of a global effect as opposed to a local one.
Not necessarily. A cloud is a summation of processes which all interact and form an equilibrium, and that equilibrium needs to be pushed to a point of instability in order to precipitate. Clouds often just dissipate through evaporation, because that equilibrium of processes shifts this way. When a given cloud has an induced higher concentration of smaller droplets (due to an aerosol interaction), it is more likely that the equilibrium will be pushed this way than the other way [that is, towards precipitation].
Good read :) now feel like Ⅰ have a grasp on why SAI perhaps Sucks where Ⅰ basically knew nothing prior to reading beyond "SAI is when aerosols into the atmosphere because reflects some frequency of light which might cool things down".
I also find myself surprised that the numbers are close enough for a factor of 2 cost increase to actually change the overall cost/benefit conclusion! I wonder if nonlinearities in costs of global warming (and possibly in the consequences of sulphur injection) mean that smaller SAI passes cost-benefit while larger ones don't?
I'm not an economist, but how it was explained to me was: if a carbon credit (or similar) for SAI is sufficiently cheaper than a carbon credit for something like carbon capture that it makes it worth the consequences, then SAI works from an economic perspective. While SAI is cheap to do sure, the carbon credit would probably end up being less value than one for a different solution.
This makes it so a factor-of-two increase in the amount of sulfur you need much more expensive, because the scaling factor of the cost of a "carbon credit" would have to be based on bulk sulfur emissions since this is how you factor in the adverse consequences.
Ah, so we're talking about whether it's more viable than other ways of mitigating extant greenhouse gases, not whether it's more or less expensive than the effect of doing nothing. That makes the numbers make more sense to me, thanks :)
"is a combination of shotwave radiation originating from the sun" I guess shotwave -> shortwave
really enjoyed the post
Ah yeah, typo! And thanks :)
I don't understand how precipitation rates can decrease globally, rather than just locally? Would that imply much higher average atmospheric humidity?
The precipitation rate reduction happens due to the interaction of sulfur aerosol with clouds when it descends - a tropospheric process. If the aerosol is injected into the stratosphere then exactly where this happens is very hard to predict since it is dependent on a combination of synoptic scale and local scale processes, which couple together. The residence time of the particles also goes beyond the reasonable prediction range of most initial condition based models.
This makes it effectively random where the aerosol descends, and how spread out it is, leading to the appearance of a global effect as opposed to a local one.
but wouldn't that water eventually come down anyway? it can't just all stay up there indefinitely, right?
Not necessarily. A cloud is a summation of processes which all interact and form an equilibrium, and that equilibrium needs to be pushed to a point of instability in order to precipitate. Clouds often just dissipate through evaporation, because that equilibrium of processes shifts this way. When a given cloud has an induced higher concentration of smaller droplets (due to an aerosol interaction), it is more likely that the equilibrium will be pushed this way than the other way [that is, towards precipitation].