"What happens next" is mentioned a lot, but in my personal pessimistic barely-informed opinion we've already passed that.

Pole ice has not grown back enough; pole ice reflects heat back into space, while naked sea will absorb it.

Permafrost has been melting in the northern regions, making thousands of years of sequestered and frozen biomass defrost and decompose, releasing huge amounts of methane.

Sea flow (whatever it was called) that pulls warm water north and cold water south, balancing out temperatures, is slowing down because of heating up + desalinization (from melting glaciers). When I read about it years ago, it said that that's what causes an ice age (as in, ice sheets going south).