Will there ever be another ice age again?

I'm very confused, if man can effect mive climate mechanisms can we negate another ice age? if not, what does all this mean, do we really have as much understanding of this as we pretend? In the 70s I remember man made global cooling, forwarded by the likes of Carl Sagan, what happened to that, he said we would die on a frozen planet by the year 2000 if we didn't change our carbon emissions, and what happened to the crisis of ozone depletion? It's worn me out.