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It’s not worse than the original problem. SO2 emissions from shipping are a huge problem for human health, and are very damaging to aquatic and coastal ecosyste

It’s not worse than the original problem. SO2 emissions from shipping are a huge problem for human health, and are very damaging to aquatic and coastal ecosystems. The potential heating effect from reducing atmospheric aerosols was predictable and was a foreseen consequence of this regulation that was considered at the time. But it’s important to remember that this is a “one time bump” to global heating, not cumulative like GHG emissions. In the overall context of global heating it’s pretty insignificant in the longer term.

chris_va 2y ago
> “one time bump” to global heating That's not entirely accurate. Short lived climate pollutants (SLCPs) that are being continuously emitted (e.g. SO4, NOx, contrail-cirrus) have cumulative effects. The heat trapped on earth is cumulative with a long equilibration time constant, and SO4 (not just from ships) has wiped out a huge fraction of the warming up to now. (disclaimer that I manage a climate research group)
- aeroman 2y ago
  I think the one time bump could be a fair description in that is doesn't add to the long term warming rate in the same way GHGs do. The cumulative effect here is pretty much all realised within about 20 years (so not an instantaneous effect, but it could be considered a one time one?)
  - chris_va 2y ago
    Sure, it's kind of a terminology question. There is heat being continually trapped by the SLCP, which analogous to a one-time (large) release of CO2. The earth will warm up in response, and will keep absorbing heat from the SLCP as long as the pollutant is being emitted. As we heat up, though, we'll radiate more heat back into space (blackbody) leading to a new equilibrium temperature (the trapped flux and outgoing flux are now both larger, but balanced). If you think about it as heat, it's cumulative. If you think about it as temperature, it'll effectively lead to a ~fixed bump (not quite a fixed one-time bump, as the effects are not linear, but one can think of it that way).
wing-_-nuts 2y ago
>SO2 emissions from shipping are a huge problem for human health This is one question I have regarding stratospheric sulfide injection. What goes up must come down right? What are the population wide effects of having higher concentrations of sulfide in the atmosphere?
nycdatasci 2y ago
The wording is "could lead to a doubling (or more) of the warming rate" which suggests a one-time bump to the slope and a significant long-term impact on global heating.
- aeroman 2y ago
  The wording of the article and the paper are a bit misleading here. It is definitely a one time even (although it plays out over 20 years) The doubling of the rate of warming only applies for the first year or two. Based on this paper, over the period 2020-2030, the impact of ship fuel regulations is warming of about 0.12K. The long term temperature trend is around +0.19K over this 10 year period.
thfuran 2y ago
What exactly do you mean by "one-time bump"? You're saying that the result would only be a transient increase in global temperature?

chris_va 2y ago

> “one time bump” to global heating That's not entirely accurate. Short lived climate pollutants (SLCPs) that are being continuously emitted (e.g. SO4, NOx, contrail-cirrus) have cumulative effects. The heat trapped on earth is cumulative with a long equilibration time constant, and SO4 (not just from ships) has wiped out a huge fraction of the warming up to now. (disclaimer that I manage a climate research group)

aeroman 2y ago
I think the one time bump could be a fair description in that is doesn't add to the long term warming rate in the same way GHGs do. The cumulative effect here is pretty much all realised within about 20 years (so not an instantaneous effect, but it could be considered a one time one?)
- chris_va 2y ago
  Sure, it's kind of a terminology question. There is heat being continually trapped by the SLCP, which analogous to a one-time (large) release of CO2. The earth will warm up in response, and will keep absorbing heat from the SLCP as long as the pollutant is being emitted. As we heat up, though, we'll radiate more heat back into space (blackbody) leading to a new equilibrium temperature (the trapped flux and outgoing flux are now both larger, but balanced). If you think about it as heat, it's cumulative. If you think about it as temperature, it'll effectively lead to a ~fixed bump (not quite a fixed one-time bump, as the effects are not linear, but one can think of it that way).

wing-_-nuts 2y ago

>SO2 emissions from shipping are a huge problem for human health This is one question I have regarding stratospheric sulfide injection. What goes up must come down right? What are the population wide effects of having higher concentrations of sulfide in the atmosphere?

nycdatasci 2y ago

The wording is "could lead to a doubling (or more) of the warming rate" which suggests a one-time bump to the slope and a significant long-term impact on global heating.

aeroman 2y ago
The wording of the article and the paper are a bit misleading here. It is definitely a one time even (although it plays out over 20 years) The doubling of the rate of warming only applies for the first year or two. Based on this paper, over the period 2020-2030, the impact of ship fuel regulations is warming of about 0.12K. The long term temperature trend is around +0.19K over this 10 year period.

thfuran 2y ago

What exactly do you mean by "one-time bump"? You're saying that the result would only be a transient increase in global temperature?