There isn’t currently a scientific consensus, as wikipedia should be pointing out, with studies differing massively depending mostly on what model of soil uptake and preservation in atmosphere is used.
We know that the majority of in air debris would not come from the explosion, which is designed to minimize fallout in all modern weapons and deployment models, but from the resulting fires. We also know from previous tests the resulting fires don’t actually last long as they tend to burn through areas quickly.
In short it’s not a sure thing, and if any cooling effect does occur it wouldn’t start to touch the average heating we’ve introduced through climate change.
IME has been sketchy as fuck since before Intel gained market dominance, much less lost it. I’m surprised it took any semi mainstream media in any country this long to report on it, there have been defcon talks about the massive black hole that is local and ime instructions for Intel chips for at least a decade now.