Most certainly the same thing that made ice cover advance and retreat in the past is still happening today. That thing that makes the ice advance and recede is

Most certainly the same thing that made ice cover advance and retreat in the past is still happening today. That thing that makes the ice advance and recede is called weather, and on a large aggregate scale is called climate. Climate is a complex multi-variable non-linear oscillator. We've been pushing one of these variables in a single direction at increasing rates for the past couple hundred years. Are you trying to imply that climate has a single variable driver and because climate change happened before the industrial revolution, that current climate change can't be hugely impacted by human activities? This would be a conclusion from a false premise (that climate is driven by a single variable).