Seems like there is a natural experiment here that could be easily tried. Let the ocean going ships switch back to the high sulfer fuel for a while and see what happens to the ocean temperature. Even if it proves the effect is small it would at least make it predictable and serve as input into models. The risks compared to other types of geoengineering seem small also since the ships were already putting sulfer into the atmosphere for decades and it's easily reversible. Maybe 6 months of allowing high sulfer fuel would be enough to get the data? If the ocean temperatures drop dramatically that would be scary, it would mean that eliminating other similar causes of sulfer pollution (low sulfer fuels being replaced by EV's) would probably have the same effect.
Agree. Short of direct stratospheric injection of sulphur dioxide, just waiving the regulation for 1 year would give us quite a lot of data about the real-world impacts, and allow us to calibrate climate models correctly. It would be a first step to building consensus that we need climate engineering in the short term in order slow the rate of climate change and lower the ecosystem impacts until we can fully shift to a non-carbon based economy. It's not necessarily the warming, it's the rapid rate of change that is the danger here.
It's an excellent and very practical proposal. Unfortunately I think geo-engineering is a hard ask politically.
Left-coded groups demanding action on climate change seem to primarily it as a moral issue, and will tend to reject what they percieve as "easy fixes".
Right-coded groups are more split with some groups wanting various kinds of action while others deny a problem exists at all.
Geo-engineering is perceived as a "techno optimist" position right now, which is a relatively insignificant demographic niche.
But that pales compared to the difficulty of getting international consensus. I feel we'd need a PR / influence campaign the likes of which the world has not yet seen.
Regarding rightists:
It would seem easier to go from "there is no problem" to "the problem can be cheaply contained", particularly without a strict requirement for mass lifestyle, infrastructure, or industrial changes.
Similarly, it's hard to imagine opportunists not using any leftist refusal to take concrete action as ammunition. This will motivate them to at least give token support.
If the problem gets worse, geoengineering will naturally be turned to, not because it's some best solution that would make everyone maximally happy, but because it's the easiest solution and requires the least coordination.
Lastly, note that you mention international consensus, but it's easy to imagine mere regional/factional consensus being enough. Nations already often engage in pollution or depletion of natural resources that crosses borders. Other players not cooperating only means scaling up independent operations to compensate.
The future belongs to techno-optimists. This is a critical coalition to build, because pragmatically, I do not see carbon capture or carbon reduction happening quickly. I think we need the climate scientific community to model an approach and put forward a recommendation.
Yes, though ocean ships are not the only source of sulfer (and even low sulfer fuels have some sulfer.) But the duration would be short, we've already been doing it for decades, and the data could be invaluable. Regardless of the politics and peoples perceptions, it seems like the right thing to do scientifically. If you're against tampering with the environment then consider that by switching to low sulfer fuels we have just tampered with the environment in a huge way, without any scientific study of the results or forethought as to what the consequences would be. Halting pollution is just as big an experiment in geoengineering as any other type of geoengineering. This is an opportunity to learn something about geoengineering at low cost and low risk. Best case may be that putting the sulfer back shows little effect. Worst case is it shows a big effect and then we have to very careful about when and how we end other sources of particulate pollution that may have an effect on warming. That would be terrible since it may mean we'd have to keeping putting poisons into the atmosphere to keep from cooking the planet for a while, but at least we'd have a better idea of what we're doing and what effects air pollution is currently causing.
