The comment I replied to said, however, "this pretty much proves we can somewhat slow down climate change by spraying certain chemicals into the air".
No, it doesn't![†] In fact, your article mentions how much we don't know and how many risks there are. I.e. it is not proven. There are still unanswered questions of literally existential magnitude. That's why the consensus view toward this amongst people who think about our options on climate all day long do not see this as a great option, never mind a proven one.
Anyway, as for your article, merely breaking an experiment into 3 phases does not make it like a clinical trial. This experiment has nowhere near the controls nor the limited blast radius of even the riskiest clinical trial being conducted today. So that's my commentary on that. Seems naive and/or dishonest to compare it to a clinical trial.
† Technically of course it's possible to lower the temperature of the earth via aerosols. But this article/observation didn't "prove it," it's not new information, and it doesn't address the main reasons not to do this otherwise obvious idea. Which again is why the scientific consensus is not currently behind it
Here is an article by a climate scientist at Cornell and the head of a climate nonprofit, which is positive towards carefully scaled piloting of solar radiation management:
https://worksinprogress.co/issue/sunscreen-for-the-planet/
I am curious if you can cite an article that is responsive to the specific plans articulated here, especially the plans to help ensure safety by scaling slowly and gathering lots of data. Which is a normal practice in all reasonable policy rollouts.