It goes to more than this. The solar wind is driven by sunspots. A lack of sunspots, low solar wind, will let more cosmic rays hit our atmosphere. Several scientists (including CERN most recently) have proven this leads to increased cloud formation, and thus lower temps. This is what lead to the Little Ice Age.
More precisely, the number of sunspots correlate with the strength of the solar magnetic field, which affects a number of things.