Geoengineering refers to deliberate efforts to manipulate the climate by reflecting more sunlight back into space, mimicking a natural process that occurs in the aftermath of large volcanic eruptions. In theory, spraying sulfur and similar particles in sufficient quantities could potentially ease global warming.
It’s not technically difficult to release such compounds into the stratosphere. But scientists have mostly (though not entirely) refrained from carrying out even small-scale outdoor experiments. And it’s not clear that any have yet injected materials into that specific layer of the atmosphere in the context of geoengineering-related research.
An assistant professor at The University of Wyoming named Matt Henry noted the experimental particle releases are taking place in Mexico because it’s a country where unproven technology is often tested.