Scientists have discovered that the recent spike in global temperatures may be caused by a reduction in sulfur dioxide pollution from shipping vessels. Ships have long emitted sulfur dioxide, which cools the planet by seeding clouds and reflecting sunlight. However, new regulations that limit sulfur in ship fuels took effect in 2020, leading to a loss of this cooling effect equivalent to a large volcanic eruption each year. Models show this reduction in sulfur dioxide pollution can explain the extra warming seen in the North Atlantic. While pollution is bad, the new regulations provide a natural experiment that gives insight into how intentional geoengineering could potentially combat climate change in the future.
There’s a spin campaign going on around this, just fyi. I don’t see it at play here. But there are neolib think tanks pushing the idea that:
while the truth is:
When you look at it like this, you can see that SOx emissions aren’t a solution. In fact there is a very good reason these emissions were regulated. It’s because it causes acid rain and ocean acidification. Certainly, we don’t want to increase SOx emissions to further mask the warming in the atmosphere, because the oceans turning too acidic is also an existential threat. And acid rain has a real cost to society. In fact this was all driven by EU regulations, and recently they looked into the data of what the SOx emission reductions were doing in terms of warming, and came to the conclusion that the acidifying effects of SOx were far worse compared to the warming effects and that the regulations were still a good idea.
You might have heard SOx proposed for counteracting the warming effects of GHG. I think that’s probably not a good idea, but I support as much research as we can muster into these things. My understanding is that CaCO3 has a far more favorable profile than SOx. Personally I am far from comfortable with the amount of confidence we have in the adverse effects of this technology but I also believe that desperate countries are going to take desperate actions regardless.
This guy proposes using seawater. That’s an interesting idea. I’m not going to watch the video and the details aren’t in the text, but I’m not sure what exactly he is proposing and based off of what studies. He may be talking about doing this at a lower altitude for a certain effect, but in general water vapor is a key GHG.