I hereby not even to elaborate too much why I think it is that population matters in the world. These are the kind of topics which are normally cited when when thinking about the population, its challenges, its problems, its opportunities, its own problems. After all, pressure on resource is a very obvious point. When world population has reached now 7 billion and is increasing by 7 to 8 million people per year, a diminishing number of course. But nonetheless it's still quite a challenge, particularly when global population is almost certain to add another 3 billion to that 6 billion with all kinds of questions as to the adequacy of resources, water, particularly in global climate change, but also food and other aspects of resources. These are all problems of security because this growth will not be equally distributed between different parts of the world. Some parts of the world will grow. Other parts of the world will shrink. The balance of power, therefore, will correspondingly change for demographic reasons, as we will see. Urban growth is remarkable. We already have megacities of 20 million people. These are going to grow even further in due course. One wonders just how far they can grow before certain aspects of the infrastructure start breaking down.