Countdown: Our Last, Best Hope for a Future in Earth? is about human population. Alan Weisman, who had written The World Without Us, visited over twenty countries to talk to various experts with different perspectives on human population. In addition to the expected scientists, politicians, and religious leaders, Weisman also visited a Filipino abortionist/nurse, a Chinese missile engineer, and a Thai economist who also distributes contraceptives and promotes their use.
Throughout the book, Weisman seeks answers to four questions. First off, what is the Earth's carrying capacity? In other words, how many people can the Earth hold? Second, how robust must the environment be to ensure our continued existence? To put that another way, how much abuse can the Earth take before we start endangering ourselves? The third question is related: Which species are absolutely essential to our survival? Which creatures should we make an extra effort to protect? Finally, how can we stabilize out population and our economy?
Weisman argues there are already too many of us. Over seven billion people live on Earth -- and a billion of them are malnourished. In countries like Pakistan, there are already disputes over water. Parts of the United States have also been affected by water shortages. In 2008, Georgia wanted to redraw its northern borders so it would have access to the Tennessee River. The state of Tennessee refused to permit that.
In the 1990's, Paul Ehrlich, who had written The Population Bomb in 1968, worked with some colleagues to try to estimate the Earth's optimum population, which they defined as the number of people who "could live well, without compromising the chance for future generations to do the same." Living well, in turn, meant that everybody would have what they needed, including food, water, shelter, health care, and education. There would still be cities and technology, but the population would be small enough to preserve biodiversity, since humans can't live without animals, clean air, or plants.
Ehrlich and his colleagues also considered energy consumption. Assuming both widespread adoption of renewable energy sources and a standard of living that calls for significantly less energy than the average American or Chinese uses, they came up with a figure of two billion people. If one raised the standard of living, the population would have to be even lower. Unfortunately, the population is expected to increase to over ten billion by the end of the century.
Making contraception readily available is key. Most women want small families of no more than two or three children; it's usually the men who want large families. In some countries like Niger, a man's prestige is linked to the number of children he's sired. In other countries like Iran and Palestine, (male) religious leaders want women to have a lot of children. In this situation, the wilier proponents of birth control will remind people that the Quran itself urges women to space their births by at least two years. Even in Mohammed's day, people recognized that having a child once every two or three years, as opposed to one right after the other, resulted in stronger, healthier women and children. Similarly, parts of the Bible recommend not having a child during a famine.
Weisman also describes the debates over which is more harmful to the environment: overpopulation or overconsumption? People who consider overconsumption to b the greater evil point out that the wealthier countries use more resources and energy than the poor ones do, even though the latter might have bigger populations. Weisman contends that both problems need to be dealt with and that population exacerbates consumption.
Weisman also believes that overpopulation may be a more straightforward problem than overconsumption. He argues there is already a viable strategy for handling overpopulation: 1) Make contraception readily available; 2) work within a culture to educate people about birth control and distribute the contraceptives; and 3) Empower women. The second part of the strategy can involve working with local authorities or distributing condoms from a neighborhood store rather than an intimidating and distant health clinic. Similarly, women are more receptive to the idea of "birth spacing," which they understand and want, rather than "population control," which might sound threatening.
By contrast, Weisman believes that reducing consumption may prove to be more complicated. Our economy depends on constant growth which means it depends on constant consumption. Reducing consumption may therefore require changes to our economic structure, and as Weisman is not an economist, he does not what changes would be effective or desirable. On the other hand, we already have some idea as to how to get out numbers under control. We just have to do it.