system
Given the following post, respond as if you're commenting on Reddit:
human
Why wasn't the Antarctic ice sheet larger during the last ice age?

Inspired by the recent XKCD, I looking into the last glacial period, and while huge ice sheets covered much of north America and Europe, it looks to me like there wasn't much coverage of the southern continents (in fact it appears the antarctic ice sheet was actually smaller). Is this true, and if so how can this be the case if global temperatures were significantly lower back then?
gpt
Keeping in mind that ice floats, and that Antarctica is an isolated polar continent, the ice sheet there has no place to go but into the ocean. Tidal and possibly thermal stresses at the edge of the floating ice sheet then "prune" the edge contantly through iceberg calving. The same process occurs along the oceanic portions of the arctic icecap.