Volcanic activity likely made it worse.
Ice ages - i.e., continental glaciations are cyclic. They seem to correlate best with solar activity.
I knew a prof who was trying to show that volcanic activity was cyclic. I don’t think he ever succeeded.
There are many factors that contribute to glaciation occurring and their severity some of them we think we, some we guess and I am sure there are some others we haven’t a clue about yet.
Variation in cosmic ray showers due to where we are on the galactic rim also contribute.
Martin Armstrong has noted the sunspot activity effecting earthquakes, volcanos, climate, etc...cyclic...remember the year without summer? June 1816 I believe....Washington DC to Maine had 2-3 feet of snow, Armstrong documents these many occurrences and ties them all with the cyclic sun spot activity. Of course the global warming idiots will deny anything other than C02. We are heading into a mini ice age.