As world population increases and incomes rise, the growing demand for goods and services results in greater derived demands for non-renewable natural resources. Not only is agricultural land used more intensively and extensively, but mineral resources (including liquid resources, such as water and petroleum, and gaseous resources, such as natural gas) are used more intensively. The extraction of land resources and their transformation into products reduce the concentrations of these resources in the earth's crust, making it more and more difficult to obtain them.
India and China each grow at the rate of 17 million people plus per year but together account for only 13 million tonnes per annum of carbon dioxide, whereas the USA with only 2.6 million new people a year produces 52 million tonnes of carbon dioxide.
People would like to consume more than they do; and rising consumption levels are among the economic aims of most governments, even if, in the short run, priority is given to building up an industrial base by means of capital formation. This aim is understandable in countries where a large part of the population is badly housed and undernourished. But the same aim is pursued in countries where a large part of the population has reached at least a modest degree of affluence. It is clear that per capita consumption cannot rise indefinitely, indeed that every form of growth is essentially sigmoid rather than exponential. In view of the many pressures on resources and the problems (pollution, congestion and so on) to which high-level consumption gives rise, it is necessary to examine the effects of different kinds of consumption on the community at large. Conserving the earth's resources means an 'energy transition' from non-renewable to renewable resources.
The fact that 20 percent of the world's population use 80 percent of global resources is an instance of the rule-of-thumb law of systems analysis that 20 percent of customers always account for 80 percent of sales; and 80 percent of stock items also account for 20 percent of turnover.