Honestly, we need to get over ourselves when it comes to sunlight modification. The fact that people are hand wringing about small trial projects that are just meant to investigate the concept is peak luddite thinking.
Do we need to be careful with the secondary effects? Yes. That's why we start with pilot projects, see how they go, and work our way up. Is a termination shock a possibility? Yes, but who cares? The alternative is we just stew in the high temps all day every day.
I get the opposition to the technology, but ultimately it comes from a place of hubris and pride. People just don't want to admit we've fucked things up so badly that now we need to resort to something as desperate as solar modification.
Well I'm sorry, but we're out of time. We're sitting here whining about possible side effects of this, when the consequences of not doing it are potentially biosphere-collapsing. Yes, I wish we had gone all in on renewables starting in 1980, but we don't live on that timeline. It takes a long time to change the course of a ship the size of an industrial civilization, and there has been immense political headwinds. Hang all the oil execs if you want, that won't change the fact that at this point, we have no reasonable path to avoiding the deaths of hundreds of millions of people and the collapse of entire biomes if we don't do solar modification. We're sitting here congratulating ourselves on not playing God as we watch as the Amazon rain forest burns down as a consequence of our own actions.
We need this technology. Yes, it sucks that we have to resort to it. But we are out of time. Right now, we are realistically looking at losing between 2-10% of the total human population by 2050 due to climate induced heat stroke and famine. Right now, the permafrost at the polls and the Greenland ice sheet are rapidly collapsing. Positive feedback loops are kicking in that mean that even if we cut off all emissions tomorrow, the temperature will still continue to snowball. This is a runaway train at this point. And the only hope we have of slowing it down is solar modification.
But people would rather keep their hands clean, refuse to "play God," and do nothing as the world burns.