Malthus' gloomy outlook on the consequences of unchecked population growth has found many champions in recent decades, perhaps most notably Paul Ehrlich. This must be the result of the tremendous growth of both national and global populations in the 20th century. Modern examinations of the consequences take both historical and prophetic tones. Jared Diamond, in "Collapse", relates chilling tales of environmental exploitation gone wild in historical societies, such as the Maya, Greenland Norsemen, and the Polynesians of Easter Island. Ehrlich warned us more than 30 years ago ("The Population Bomb") of the coming collapse of modern societies should population growth remain unchecked. Yet, here we are; we're still here, and the growth of the global human population is accelerating. Why then should we listen to Malthus and his modern counterparts?
The notion that the human population can continue to grow without limit is simply illogical. As I pointed out in my previous post, non-human populations in nature can never sustain Malthusian growth. So why have we humans seemingly accomplished this over the past few centuries? Are we special? Yes and no. First, let's take a look at how we've manged it.
Modern human society has at least three advantages over its predecessors: increased food production, reduced mortality from disease, and increased security. I suspect that the global population growth rate probably began to accelerate as agriculture was developed in different places, which are historically fairly recent events. More food equates to more people; surpluses support population growth and larger populations. In more recent times, humans have become increasingly efficient at suppressing and reducing mortality due to diseases, especially those caused by infectious agents. The growth of civilized societies (if we choose to define civilized as living in cities) was also often accompanied by increased security and reduced mortality from human aggression. Yes, believe it or not, today we do a far better job of feeding large segments of the global population, controlling epidemics, and keeping ourselves safe from murderous neighbours (both domestic and foreign). Famines no longer sweep through Europe, smallpox has been eradicated in the wild, and wars tend not to last Thirty Years.
Yet one can't help but get the feeling that things are cracking at the seams. Food shortages have reached crisis levels in many regions. The Black Death probably required several decades to make its initial journey from Asia to Europe in the 14th century, while today we worry about the spread of a global pandemic on a timescale of weeks. And sadly, we now have the capacity to kill thousands daily with conventional warfare, and millions within minutes with weapons of mass destruction. Are these cracks related to population growth? Is the human population reaching a carrying capacity limit? I think that these are very difficult questions to answer, but the answers in my opinion are both yes. There is no shortage of people who are ready to disagree with me, and some of them will point to very clever arguments (all of which I judge to nevertheless be without merit). We'll explore the questions, arguments and counter-arguments in subsequent posts, as well as the connection to global warming and climate change. In the meantime, check out this very entertaining link.