Today, we are close to the critical moment when conventional economic growth becomes impossible on a finite planet, constrained by two parallel factors: resource depletion and pollution. Tthe depletion of fossil fuels and other mineral commodities is placing heavy constraints on both industrial and agricultural production. We are not running out of anything yet, but the cost of extraction is increasing, just as the damage that extraction causes to the ecosystem. On the other side, pollution is appearing in more than one form. Chemical pollution is growing in terms of heavy metals, endocrine-disruptors, and other poisoning substances, while climate change can be seen as another form of pollution generated by the excess of CO2 in the atmosphere.
These constraints are slowing down economic growth and, eventually, the population trend will be affected, too and models based on the method called "system dynamics" show that a population decline should start during the first half of the 20th century. We are already seeing it in several industrialized countries, while traditional agriculture-based countries are moving in the same direction.
The upcoming population decline is not necessarily a bad thing. It is expected to lead to a lower demand for dwindling natural resources, lower emissions, and, hence, lower pollution. In general, a population decline will lead to a lower degree of stress on a badly overexploited ecosystem, including Earth's climate. Fewer people may also mean fewer wars because there will be no more growing populations in search of living space.
However, population reduction may also bring enormous problems in terms of maintaining the structure of a society that so far has taken economic growth for granted. Shrinking may be so fast that it could bring about the collapse of some expensive structures that have been built over the centuries, such as public education systems, public health care, and scientific research. During the transition phase, society will necessarily consist of an increasing fraction of elderly people, who may become a heavy burden for the young. In addition, the growing population in some African countries may lead to a global imbalance, with a trend of emigration toward regions whose population is declining. That may also lead to social and military conflicts.
This book is an attempt to evaluate current trends and project them into the future on the basis of existing data and models. You will find in it a broad sweep of the trends and problems of the human population. It discusses the subject on the basis of more than one viewpoint: biological, historical, economic, and social factors are all considered. In particular, it is based on the previous experience of the Club of Rome examining global problems from a systems dynamics perspective, on the basis of models, but also in terms of qualitative interpretations. It is the approach that was used more than 50 years ago for the Limits to Growth report, and that led to fundamental insights into the trends of human civilization.
