Slide 36 in this series.
The diagram below gives a conceptual explanation for how solar activity can vary the amount of cosmic rays that can hit the earth's atmosphere. Cosmic rays have been shown to generate ionized particles in the atmosphere that are needed to nucleate clouds at low altitudes.
This greatly can affect climate as was discussed in several places in the sections of this tutorial.
NEXT: More details on cosmic rays and low clouds is next.
These links are the topics for this section.
Modelling Temp Natural Factors
Earth and the Science of Radiation
Milankovith Overlapping Cycles