An alternative to the Firetree Flood Maps, which has been around for a while (it has a US focus, but the maps are worldwide) They seem to have been 'discovered' by a lot of people this week and are all over social media, but have been out for a while. They are also not without their issues, and shouldn't be taken literally as meaning this WILL happen.... but are being described in that way.
This map shows the possible impact on the Ely area.
You can see the 'potential impact' on the Fens here of a 7 foot increase in sea level. The default imperial units gives away the site's American origins. The Environment Agency's maps are probably more reliable in terms of the actual flood risk.