Wasn't it hypothesized that the collapse was due to an Ice Age? I thought there was strong geological evidence for that, and the challenges it put on human population, but I don't know enough about history to place the last Ice Age on a timeline relative to the Bronze Age without doing research.

Update: Upon some brief research, the last Ice Age ended about 12,000 years ago, whereas the Bronze Age Collapse was around 1200 BCE. So totally unrelated.