You get that that chart is completely made up, right? That is, despite being an extrapolation of the future, there are no error bars as a function of time?

Furthermore, we lack a fundamental model for how cloud cover will change over the course of a deep minimum. And therefore we cannot accurately predict what the future will hold.

The Svensmark experiment from December 2017, confirming it:

Increased ionization supports growth of aerosols into cloud condensation nuclei - https://www.nature.com/articles/s41467-017-02082-2

I should have said, it’s hard to take this link seriously, given that chart.

In other words, I completely agree that we have no idea what the impact will be if this minimum does occur, or if indeed it does occur at all.

I think we've a little idea-

https://en.wikipedia.org/wiki/Maunder_Minimum