This may just sound a pretty dumb question so please bear with me. If the ice is melting anywhere on land, then presumably the sea levels will rise. If it's melting on the oceans then the sea levels will remain unchanged.
Now I do not know this because I haven't looked into it in any great depth, but I have not seen any evidence of any sea levels rising anywhere. If the situation is becoming 'critical' as some would suggest, why has the level not risen? Or has it and I just missed it in Portsmouth Harbour...?