global population
 

See John McCarthy's pages at http://www-formal.stanford.edu/jmc/progress/index.html

 

Human Population and its Limits

Population statistics for the UK compared with the US and elsewhere

John notes that both China and India with their very large populations and much higher population density than the US have for some time adopted policies to control population growth. However he fails to note that these are far from the most densly populated countries. China has a land area of 9,326,410 sq km and a population of 1,306,313,812 and India a land area of 2,973,190 sq km and population of 1,080,264,388. Compare this to the United Kingdom land area of 241,590 sq km and population of 60,441,457 which isn't even the most densely populated country in Europe and has no government policies to limit family sizes. Perhaps tax incentives for families aren't as generous as some other European countries, but most likely the education of women and their desire to participate in roles other than wife and mother is what changes things most.

Migration and sub-groups

John observes, as many other have, that certain religious groups tend to have many more children per family than is typical in most western countries. He also observes, as few have, that defection from these groups is also significant. My gut feeling is that these two things, and maybe others, will balance in such a way that no sensible person should consider it any more likely that the whole planet will eventually be populated by Orthodox Jews than by African hunter-gatherers. (Though if we take the evoloutionary view of our species, the latter is almost certainly what did happen once. Though it took a very long time, and is unlikely to be repeated).

Sex and population

I disagree with John's view that desire for sex drives population growth (even in rabbits). Most living things are capable of reproducing at, or above, the rate of population growth their environment can sustain. Darwin has made it clear to us how important sex is in ensuring the fitness of the population but it doesn't control its size. Food supply and other environmental factors limit populations, not matings. For those living today in the West it's often hard to imagine that global human population is limited by food supply, but for the most part it always has been and probably always will be.

What the experts have to say...

UN World Population Prospects 2006 edition