CONCEPT OF SUSTAINABLE DEVELOPMENT - A MEANINGFUL GOAL

Mankind's present rate of energy consumption is about 10 TW (or about 25% of the energy used in photosynthesis). It is about a factor of 18 more than that of advanced agricultural man and 300 more than that of hunting man. It has been estimated that a 5-10-fold increase in economic activity is required over the next 50 years to meet the needs of an increased world population as well as to begin to reduce mass poverty. Assuming that this increase in economic activity implies a corresponding increase in energy consumption, it is considered to be impossible without catastrophic environmental consequences. Mankind is now the principal geochemical agent on the planet. It follows that environmental problems are on a global scale. Each of the principal components on which mankind depends, air, water and soil, is vulnerable to degradation and pollution. This leads to the need for a reassessment of all our resources. For instance, consumption of ah known fossil fuel reserves would lead to an atmospheric CO, content of about 1900 ppm. Such a level is clearly unacceptable and this demands a revision of the earth's energy reserves. Sustainable development has come to be accepted as a key goal in environmental policy. Based on mankind's present and projected energy budget, it is seen that sustainable development is not occurring now and will be impossible within the next 50 years. Calculations suggest that a world population of one billion with reasonable living standards is sustainable into the indefinite future. This can be achieved by ensuring one child families for about 100 years. If the present population and economic trends continue, ecological catastrophe is likely to occur in many countries over the next few decades as ecosystems become more degraded and more marginal for human existence. These findings suggest that our whole ideas on population increase and resource consumption require urgent revision.