Black Blizzard, page-31

Hi Greenhart,
Yes the major effect would be in the Northern hemisphere because that is where most of the land mass (and population) is.

In my previous role as a mining engineer I was fortunate to be involved with Anthropologists who do Aboriginal cultural studies in the Pilbara.
I was talking to one bloke one day who told me that during the last ice age, humans were still living in the Pilbara, even though it was extremely dry.

During an ice age, there is so much moisture that has been stripped out of the atmosphere that even areas like the Pilbara were dry, with cold, strong winds all the year round. And the Aboriginal people continuously occupied these areas. Amazing.

So a long winded post, but in answer to your post yes there would be lots of boat people, but I don't think they would find things in Australia very good. Darwin might be OK, but most of Australia would be uninhabitable imo.