Most studies have concluded: no, the nuclei they create are too small.

One study seems to be ongoing:
https://home.cern/about/experiments/cloud

It has found, to date, that:
Quote:


Booby is such a blob he could never think of checking on something on Google.

No proof so far that GCRs cause cloud formation.

OTOH as the world warms it is not hard to see there is more evaporation and hence more clouds. IOW, GCRs are just a transparent device by a transparent liar like Dubyne to explain the increase in clouds.