As the Rio Declaration on Environment and Development says, ‘Human beings are at the centre of concerns for sustainable development. They are entitled to a healthy and productive life in harmony with Nature.’.
Indeed, as we have seen throughout the module, the population —and, above all, its quick growth— is the main factor of the environmental degradation. The fundamental idea is that the bigger the population, the bigger the impact: a larger number of inhabitants means, at last a priori, a greater demand of natural resources (food, energy, etc) which the planet has to supply in order to guarantee them a good level of life quality.
For this reason, most of the studies on the global population impact on the environment focus only on the total amount of inhabitants and its evolution within the time, that is, the growth. Accordingly, many authors try to raise the alarm, since they analyse the rhythm of world population growth, which has risen the world population amount to the current number of seven thousand million inhabitants, the highest rate in history. As a consequence of this perspective, many authors suggest slowing down the growth rhythm and they even defend the zero growth theory.
However, focusing only on the number of world population means having a partial view of the issue, since at regional scale, countries have strongly different growth rates and socio-demographic structures (represented by population pyramids). These differences are mainly due to the diverse stages of each country’s demographic transition. Simultaneously, another variable to be taken into account when measuring the environmental impact of a population is its territorial distribution: generally, the authors agree on the urbanisation growth around the world being one of the aspects that has mostly brought the environmental degradation.
In order to measure the population impact on the environment, there have been traditionally defined certain indicators. However, the indicators for the population dimension are little satisfactory, from the geographical point of view. We are essentially pointing out to the relative indicators of goods and services consumption, shown in values per capita, which only represent the population volume, without taking into account other demographic dimensions. In principle, these indicators are intended for the situation comparison between two populations with different volume. However, this comparison will be imperfect, if the effect of the rest of demographic variables, especially the age structure, is not considered. Consequently, the advance of the demographic perspective incorporation within the environmental studies requires the development of the sources of statistical data and the methodologies, in order to create a new generation of indicators, much more suitable from the demographic viewpoint. Thus, from the perspective of demography, a proposal of indicators for the populations’ environmental behaviour should approach to:
- Specific behaviour indicators according to the diverse groups of the chosen structure (or structures). Therefore, it could be observed the sensitivity of the current phenomenon or process for the demographic variables, which is an indispensable element before making a systematic comparison of several populations’ integral indicators.
- In order to establish the differences between populations and territories, global indicators to control the incidental distortions that diverse demographic compositions may insert within the comparisons between populations. The standardisation is the method provided by demography that allows the integral indicators to work correctly.
However, when measuring the environmental impact of the word population from its demand and need of environmental resources, and from the repercussions of its economic activities, from its quantitative size, it is important to consider the qualitative aspects too, as the socio-cultural patterns of consumption. Probably, the goal to be reached, the sustainable development of the world population, won’t only depend on the final amount of inhabitants, but, above all, on the adoption of new patterns of responsible consumption, which would give priority to the endogenous resources, the research on new types of clean and renewable energy, etc. For this reason, it is necessary to complement the content of the current module with the information found in the rest of modules on other aspects of the sustainable development.