Leasowe and most of Moreton is below sea level and would be flooded. Buy a house on top of Bidston Hill or in Liscard/New Brighton, you'll be nice and safe :o)
there are massive overflow tunnels under Leasowe rd goes to the tanks so they will be ok
But no tank has the capacity of the Irish Sea and if/ when global warming does occur to an extent that large areas of land are flooded then we are talking about such an expansion of the sea.
Going back to the map in the initial post. I was reading the "History of the Hundred of Wirral" (Mortimer - mid 1800s) and in that it describes how the topography and geological layout of Wirral/ South Lancs and North Wales leads to a conclusion that ORIGINALLY there was a land bridge between New Brighton and South Lancs ie say Liverpool in modern terminology. What we call the Mersey drained eastwards towards Chester and then into the River Dee.
Interesting thought, and technically a sound thought.
Snod