Tens of thousands of homes and businesses in Melbourne face a bigger risk of tidal flooding by century's end, and major roads, tram routes and industrial areas could disappear under water due to future sea level rises, new modelling shows.

The updated modelling of possible sea level rises caused by climate change predicts Victoria's coastline could be hit by sea level rises of two metres or more by 2100, due to the rapid melting of ice sheets in Antarctica and Greenland.

Streets in Elwood after a flash flood in December. Credit:Wayne Taylor

A two-metre rise would flood several low-lying suburbs in Melbourne including South Melbourne, Albert Park, Port Melbourne, Southbank, Docklands, Altona, Williamstown, Elwood, St Kilda, Seaford, Carrum, Bonbeach and Aspendale.

Large areas in Geelong and the seaside towns of Barwon Heads, Queenscliff and Point Lonsdale would also be heavily inundated at high tide by century's end, it is predicted.