Contemporary forestry and agriculture too should be seen as extractive industries since, in effect, they are mining environmental systems. Of all human activities, however, it is the relentless tide of brick, concrete and tarmac that creates the greatest environmental damage, sterilising an ever increasing area of land. Yet while the amount of fertile cropland, healthy pastures and productive forest go down, human numbers and individual expectations continue to rise. Insofar as environmental degradation is addressed, it is primarily seen as a Third World problem. The African Sahel is often cited as a prime example of the problem.
Population growth is the primary driving force extending and intensifying environmental degradation.
Even in the case of hunter-gatherer groups, practising 'slash and burn' farming in tropical forests, an increase in their small numbers means the clearance of bigger areas of land as well as an earlier return to previously exploited areas before they have time to recover. However, it is the incredible explosion of human populations in agricultural and urbanised societies that generates the biggest demand for more food and other goods, followed in turn by increased pressure on the land. At the same time, individual lifestyle choices can make a dramatic difference. For example, human exploitation of the land would be much smaller scale and less intensive if meat-centred diets weren't so prevalent. In some regions, the role of animals as symbols of status and wealth obviously contributes to overgrazing.