This doesn't seem so far fetched.
The U.S Congress Research Service are currently looking at various ways currently to manipulate the atmosphere.
Here is the document from 2023.
If there are documents already about it then who knows what is actually happening.
One thing I have thought about
To conspiracy theorists, if global warming is a myth then believing in Chemtrails would be silly, there would be no need to do it right?
Stratospheric Aerosol Injection (SAI)
SAI as an SG method would require the dispersion of sulfates in the stratosphere to createmanmade aerosol particles in order to make the atmosphere more reflective to incoming solarradiation energy and mimic the cooling effect observed after a large volcanic eruption.20A varietyof methods have been proposed to add sulfates to the atmosphere, including “aircraft, rockets,artillery, and pipes elevated to high altitudes carrying aerosol precursors.”21
Marine Cloud Brightening (MCB)
The MCB technique would involve spraying a mist of submicrometer seawater particles intomarine stratocumulus clouds.36 The spray particles would form small droplets within the cloud;these droplets would increase the cloud’s reflectivity, increasing the amount of incoming solarenergy reflected back out into space
Cirrus Cloud Thinning (CCT)
CCT would involve adding an aerosol of insoluble particles to the cloud, whichwould form larger crystals than the smaller ice-only crystals. These larger crystals would fall outof the atmosphere more quickly than the naturally forming ice-only crystals, thus thinning thecirrus cloud and allowing more heat energy to escape.4