Yeah GSM is a thing. It has always been a thing. We are near the end of a solar minimum, and the next solar minimum in roughly 15 years is most likely going to be a serious issue.
Anthropogenic global warming is a completely different topic and it's best to keep these things separate if a rational discussion is to take place.
Increased cosmic radiation and coronal mass radiation have a direct effect on seismic activity, volcanic activity, and weather.
Hopefully you all recognize that the earth is an electromagnetic system. It generates it's own magnetic field, and it is why you get 2 current events during 1 lightning strike. Our upper atmosphere (ionosphere) is also an electromagnetic system that encapsulates the earth, and is separated by a semiconducting layer (air, rocks, water etc). At the mantal / crust boundary, minerals slowly transition state from liquid to solid, forming crystals. Quartz and olivine are two such examples, and they form in very large sheets covering thousands of square kms.
These crystals are piezo-electric in nature, meaning that when an electromagnetic field is applied to them, they produce a physical force. This is how quartz crystal clocks work. When cosmic and solar coronal ejecta (both have very high energies) interact with the ionoshpere, the electric potential between the two electromagnetic systems increases. This in turn triggers physical forces within the earth crust, and especially along the plate boundaries.
Now consider weather systems, which are also electromagnetic systems. This increased charge potential couples with these weather systems too, intensifying them and also applying a physical force upon them that alters their course.
These cosmic rays and CME also act directly on clouds, which causes them to disperse. This means less rain, but also reduces the heat retention capacity of the atmosphere. during GSM, the total energy output from the sun is reduced, and the reduced energy entering the earth's system combined with the reduced ability to retain captured heat means that the GSM will bring with it significantly colder temperatures, especially in the Northern hemisphere. Since atmospheric convection drives oceanic circulations, we can expect disruptions to things like the gulf stream and the Beaufort gyre.
I live in a northern continental climate, and I have been preparing for a shift in hardiness zone downwards because of the approaching confluence of long time scale natural cycles. This last GSM was mild compared to the next one, and we experience widespread crop losses in every staple food.
Unfortunately for us all, this next GSM coincides with the earths magnetic pole reversal cycle. That's a different dynamic, but what it means is that the effects from cosmic rays and CME will be very much magnified.