safe from what though ???
it might be a good idea to classify the threats and list the possible safe areas accordingly ..
Nuclear attack .. safe areas unknown because it depends where the nukes land and the prevailing winds etc ..
Floods and rising sea level .. anywhere high and inland ..
Civil Unrest - probably the country side .. places like Devon / Cornwall - remote areas ?
Just my thoughts ..
I think there are no really ' safe ' places in the UK and we should just move when we feel our intuition nudging is IMO
