Something I've wondered since the climate change discussions began, actually earlier since I was a kid, is: How long did it take for the last ice age, some 25000 or so years ago, to end. Geologically, 25000 years is less than a blink of an eye. Here in New England the glaciers from that ice age were supposedly up to a mile thick. How long did it take for them to melt? Back a bit earlier in time, how long did it take for them to form?