Admittedly this could be rephrased for a ‘B’ movie titled “It came from the ice”, but we are not talking movies. What we are talking about are viruses and other biologicals that have been frozen in the ice thousands of years and are now melting out from global warming. The biggest concern is we may have no natural resistance to them.
Before you go and make an assumption this is not possible, there are a few minor considerations you need to weigh. Frozen mammoth carcases have been recovered in Siberia. We are not talking about just bones, but flesh and hair. This has happened more than once.
All things considered mammoths are not the only things finding their way out of the ice, and you can just use your imagination as to what they would be.
Also the chances that humans have encountered these biologicals is very remote. The global human population was less than a million people and they only lived in tempered climates. So that clearly makes this a bit of a risk. Assuming some frozen remains finds its way into a population center and starts to thaw, the risk of contamination goes up. That can happen as easy as the bird flu gets around today.
Admittedly this post is short on words, but big on possibilities. Nature fights back in many ways.