Over in The Guardian John Vidal tells us of the horrors of continued population growth and urbanisation. As ever with John Vidal on matters environmental the horrors are ill-informed. The mistake being that usual one of not noting that the problem being complained of is already solved.

If population growth continues unabated, if urbanisation continues at recent rates then yes, we would end up with 100 million people conurbations. But the one precludes the other, rather an important point to note really:

Under the researchers’ extreme scenario – where countries are unable to control fertility rates and urbanisation continues apace – within 35 years more than 100 cities will have populations larger than 5.5 million people. By 2100, say the authors, the world’s population centers will have shifted to Asia and Africa, with only 14 of the 101 largest cities in Europe or the Americas.

The point to note being that urbansiation in and of itself controls fertility. This is a rather well known fact. Out in that idiocy of rural life there's not a great deal to do of an evening except bed but more importantly children rapidly become an economic asset. Humans tend to increase the number of economic assets they have access to. In urban settings children are costs for many more years. Humans tend to reduce the number of economic costs they are subject to.

Urban fertility rates are lower, substantially so, than rural. More than this, death rates of children, of all in fact, are higher in the foetid slums being predicted than they are out in the country. London, as one example, had negative population growth absent continued immigration from the countryside for many centuries.

It's simply not possible for us to have rural fertility and survival rates, therefore population growth, in these growing urban centres. And the worse the cities are are then the less possible this is. 

An impossible future is a strange thing to be worrying us all with, isn't it? But then John Vidal on matters environmental....it's a matter of great amusement to find that The Guardian, on the same day, makes this very point in another article:

 Despite appearances, cities are not the cause of rising human numbers. In fact, they are the solution. People in cities almost everywhere tend to have fewer children than their compatriots in rural areas. The average woman in Kenya has 4.3 children, whereas those living in the capital, Nairobi, have just 2.7. In India the average is 2.4 children, but in Delhi it’s just 1.6 and in Mumbai 1.4. That’s lower than London, where the average is 1.72.

Ah, yes, John Vidal....