As I recall, Bond events have been proven and accepted. However, the cause of these events are still unclear. You have remarked earlier on the cyclical nature of Bond events and, to my mind, cosmic movements are very cyclical.
Is it not possible that Bond events are caused by cosmic impacts or earth's orbit crossing meteorite/asteroid clouds or swarms? The actual impacts may be of less importance than multiple "Tunguska-type" explosions in earth's atmosphere that could blot out the sun for extended periods. The drop in temperatures and larger snow cover would further deflect the sun's rays and thus trigger ice ages.