Seven Billion Humans

According to United Nations estimates, the world's human population reached seven billion yesterday. As there have been many news stories about this over the past month, many people are already aware of this, but I suspect a large percentage of them haven't really thought about how incredible that number is -- and how scary.

Numbers in the billions, whether referring to people, money, or other things, are thrown about so often in news stories that it's easy to forget how big a number a billion really is. For instance, if you started counting at one number a second, you could count to a million in a little over 11 days of constant counting, but it would take over 30 years to count to a billion. So seven billion people is a lot of people. What makes this number even more incredible is how much larger it is than previous population totals. Before the development of agriculture about 10,000 years ago, the total human population probably never exceeded 10 million. The world's population grew to several hundred million by the time of the Roman Empire and the Chinese Han dynasty, but it was only with the industrial revolution that it started to grow dramatically. Soon after 1800, the world population first hit one billion. It doubled in a little over a century to two billion, and by 1960 it was three billion. In my own lifetime, the world population has gone from under four billion to today's seven billion. In other words, today there are almost twice as many people in the world as there were when I was born around forty years ago, and there are seven times as many people now as there were just over two centuries ago.

This continual growth has meant that we have had to constantly expand food production at a rapid rate to feed everyone. Not everyone gets enough food, of course, though at present this is a distribution problem rather than an indication of an absolute shortage of food. However, many experts fear we will not always be able to increase food production fast enough to keep pace with population growth. Our growing population has also put a great strain on many other resources, from fresh water to mineral and energy resources. In addition, humans are squeezing out many other species. The biggest reason that many large mammals such as tigers and orangutans are endangered is that we are taking their habitat away with our constant greed for more land to exploit. It is not unusual to read about efforts to cull animals such as wolves and bears because they are "encroaching" on agricultural or ranch land, but in fact in almost every case it is really the humans who originally encroached on the lands that these animals once roamed freely, so one could argue that the culls are aimed at the wrong target, a point humorously made in this Non Sequitur cartoon by Wiley Miller.

Though few would seriously argue for a cull of excess humans, more and more people are starting to openly acknowledge that our environmental problems and overpopulation are closely intertwined, and so advocate measures to slow and eventually stop population growth. Interestingly, it is only recently that a few environmental groups have begun discuss the problem of human population growth head on, as related in this NYT article. The more extreme coercive measures adopted in China are obviously not acceptable, and other issues like gender imbalances and population aging have to be addressed, but it is equal clear that it will be impossible for the Earth to sustain population growth at the current rate forever, especially if more and more people in big countries like China and India demand a standard of living equal to that in the developed world.

Other than sex education, promotion of family planning, and improved access to contraceptives, one of the most effective ways to control population growth is by empowering women. The more control women have over reproduction, the less uncontrolled growth we will see. Of course, general measures to alleviate poverty will also help, as generally speaking more economically developed nations have lower birth rates. In the developed world, it would also be good to see more adoptions and fewer fertility treatments, as there are more than enough children in need of parents for all the couples who want children (though I am aware that the red tape involved makes putting them together a difficult process). However, most efforts at reducing population growth will have to focus on the developing world. Solving this problem won't be easy, but with effort we can ensure that humanity doesn't overrun the world completely and thereby we can make life better for humans and all our fellow inhabitants of the Earth.