DRESDEN optIt is a great honour for me to address you in this beautiful church. The Frauenkirche is a symbol of the victory of faith and peace over the brutality and destruction of war. It was rebuilt and reconsecrated after it had been destroyed in one of the most dreadful episodes in a dreadful war. It stands as an indomitable symbol of mankind’s ability to resurrect the best qualities of our civilization from the ruins and ashes of the worst.

Demography, as they say, is destiny.

Much of human history has been driven by the movement of people and the growth of populations.

Just consider the impact of migrations on mankind’s history:

Now, once again, in our globalised world, people are on the move.

The dominant image of our time may be the hundreds of thousands of refugees who each year are risking their lives in unseaworthy boats to reach Europe. As I speak there are hundreds of people, huddled together in leaking boats, desperately trying to reach the southern shores of Italy, Spain and Greece.

All of this is happening at a time of the unsustainable growth of the human population and dramatic changes in life expectancy and fertility.

In 1950 global life expectancy was only 47 years – by 2011 it had increased to 70. A Japanese girl child born today can expect to live to 107.  An English girl baby will live till 103.

At the same time fertility rates in many European countries have plummeted far below the levels required to sustain present populations. At the present fertility rate, the population of the European Union will shrink by 100 million by the end of the century. In some countries it will fall by half.

In the coming years more and more refugees can be expected to seek safety and a better life in the prosperous and secure societies of Europe and North America.

What is already a steady flow of refugees could become a torrent if climate change causes a succession of bad harvests in the developing world. How would Europe react if 10 million refugees a year were to knock on its doors and appeal for refuge?

At what stage would the so-called “lifeboat effect” come into play: that is the point when those in the lifeboat stop doing all they can to save and haul aboard shipwreck victims – to the time when they violently fend them off for fear of being fatally overloaded?

Everywhere populations are becoming more and more heterogeneous. It is predicted that by 2050 a third of Britain’s population will comprise minorities.

The days of the single ethnic group nation state are gone. One of the central challenges in the emerging multicultural world will be the accommodation of diversity.