This article is almost a year old, but wanted to bring attention to it since it doesn't seem to be talked about much. TLDR: two Harvard scientists will conduct a solar radiation management experiment over Tucson, AZ sometime this year. Searching the topic, I mostly find basically the same info in multiple articles. So far, I have been unable to find an exact start date for this project. I have also not been able to find which agency or power granted permission for this to move forward.

Solar radiation management is a way of blocking sunlight away from the earth to lower temperature, much like a large volcanic explosion blocks the light. These experiments, unlike cloud seeding (which is used to cause rain), have mostly been performed through computer models. There was one that I found performed in Siberia (lost the link when my hard drive crashed last month). There is debate in the scientific community about the safety of people living where these experiments may be performed, the long lasting effects on weather changes, and possibly damaging the ozone layer.

There is a meetup being planned, link to protest this experiment.

Also of note, the company providing the gondola balloon is called World View. Don't know much about them, other than much of the leadership is NASA based.

As far as a conspiracy angle on this info, I just find it unfair to the citizens as it appears that they had no say. Also, while this is a small scale experiment, any ramifications are unknown. Tucson does have unpopulated desert in it's city limits, but any "fallout" that may occur is totally unknown. I don't know, but it seems reckless and a little sneaky. And a sidenote that may be of no consequence, defense contractor Raytheon does have a location in Tucson.