In only 20 times the length of time since the Battle of Hastings, the Polar Ice Cap has shrunk from London to the other side of Greenland. And the English Channel has filled with sea water.
In only 100 times the length of time since the Battle of Hastings, the Polar Ice Cap has expanded from the other side of Greenland all the way to London and then back again. And the English Channel has emptied of sea water and then filled-up again.
More: http://steelydanswarandpeace.blogspot.co.uk/2009/01/will-brighton-be-swallowed-by-sea.html