Irish Times: Sir, As the world watches, debates and, hopefully, responds to the refugee crisis unfolding in the Mediterranean, it may be worthwhile reflecting that this current wave of migration is simply a taste of things likely to come within the next few decades. Over 50 per cent of humanity now lives within a few kilometres of the sea, and most of the worlds major cities are on the coast and already liable to flooding. It is now overwhelmingly accepted that, as global climate change continues, many coastal...