We are not that close to another full-on glacial period (or ice age as some here are calling it, technically we are still in an ice age, this is an inter-glacial warm phase).
Reason why is that orbital cycles that contribute to the glacial maximum are only changing slowly this time around and the inter-glacial could linger 30 to 50 thousand years, by which time, I would imagine that science will have solved many questions about the atmosphere and we may have ways of preventing a glacial advance of any large extent.
Perhaps it will become mandatory to generate electricity with coal-fired power plants, and the 100 billion people of earth will all have to drive six hours a day. Come to think of it, when the earth is all one extensive city, whether the AGW theory is right, partly right or wrong, we’ll have a giant urban heat island and that should keep the glaciers where we want them.
I am not being facetious here, another glacial maximum at any time during our future will be a mass extinction event forcing everyone to cluster together in about half the current land mass, and the people who are already there are not going to want our white asses any more than we appear to want theirs, so I suspect glacial maximum is pretty much equivalent to global warfare and famine.