The Threat of Population Growth Pales Beside the Greed of the Rich

I cannot avoid the subject any longer. Almost every day I receive a clutch of emails about it, asking the same question. A frightening new report has just pushed it up the political agenda: for the first time the World Food Program is struggling to find the supplies it needs for emergency famine relief. So why, like most environmentalists, won't I mention the p-word? According to its most vociferous proponents (Paul and Anne Ehrlich), population is "our number one environmental problem." But most greens will not discuss it.

Is this sensitivity or is it cowardice? Perhaps a bit of both. Population growth has always been politically charged, and always the fault of someone else. Seldom has the complaint been heard that "people like us are breeding too fast". For the prosperous clergyman Thomas Malthus, writing in 1798, the problem arose from the fecklessness of the laboring classes. Through the 19th and early 20th centuries, eugenicists warned that white people would be outbred. In rich nations in the 1970s the issue was over-emphasized, as it is the one environmental problem for which poor nations are largely to blame. But the question still needs to be answered. Is population really our number one environmental problem?

The Optimum Population Trust (OPT) cites some shocking figures, produced by the UN. They show that if the global population keeps growing at its current rate, it will reach 134 trillion by 2300. But this is plainly absurd: no one expects it to happen. In 2005, the UN estimated that the world's population will more or less stabilize in 2200 at 10 billion. But a paper published in Nature last week suggests that there is an 88 percent chance that global population growth will end during this century.

In other words, if we accept the UN's projection, the global population will grow by roughly 50 percent and then stop. This means it will become 50 percent harder to stop runaway climate change, 50 percent harder to feed the world, 50 percent harder to prevent the overuse of resources. But compare this rate of increase with the rate of economic growth.

Many economists predict that, occasional recessions notwithstanding, the global economy will grow by about 3 percent a year this century. Governments will do all they can to prove them right. A steady growth rate of 3 percent means a doubling of economic activity every 23 years. By 2100, in other words, global consumption will increase by about 1,600 percent. As the equations produced by Professor Roderick Smith of Imperial College have shown, this means that in the 21st century we will have used 16 times as many economic resources as human beings have consumed since we came down from the trees.

So economic growth this century could be 32 times as big an environmental issue as population growth. And if governments, banks and businesses have their way, it never stops. By 2115, the cumulative total rises to 3,200 percent, by 2138 to 6,400 percent. As resources are finite, this is of course impossible, but it is not hard to see that rising economic activity -- not human numbers -- is the immediate and overwhelming threat.

Those who emphasize the dangers of population growth maintain that times have changed: they are not concerned only with population growth in the poor world, but primarily with growth in the rich world, where people consume much more. The OPT maintains that the "global environmental impact of an inhabitant of Bangladesh … will increase by a factor of 16 if he or she emigrates to the USA." This is surely not quite true, as recent immigrants tend to be poorer than the native population, but the general point stands: population growth in the rich world, largely driven by immigration, is more environmentally damaging than an increase in population in the poor world. In the US and the UK, their ecological impact has become another stick with which immigrants can be beaten.