The natural environment—air, water and soil—is not only essential for supporting life, but is also the medium through which the technological waste products of society are consumed and restored. At lower levels of industrialization and lower population densities than are now prevalent, the capacity of the natural environment to absorb and recycle waste appeared limitless. Increasingly, however, nature's capacity to assimilate waste is being threatened because of the rise in industrial production which has resulted in a much larger volume of emissions of organic and inorganic compounds from mining, refining, chemical production and manufacturing activities. In addition, certain industries (such as aluminium smelting plants and electricity generating stations) require large amounts of cooling water and discharge large quantities of heat into streams and rivers. Technology is also responsible for production of discharges of fine particulates, sulphur dioxide and nitrogen oxides, into the atmosphere, and for the great number of undegradable waste products from the plastics, metallurgical, glass and petrochemicals industries. Further impacts are the increased number of motor vehicles and rising volume of traffic, leading to higher level emissions of carbon monoxide, nitrogen oxides and lead; and the increased use of incineration, both by municipalities and industries, as a means of disposal of solid wastes, leading to the emission of a complex mixture of pollutants.
The rapid and uncontrolled introduction of new technology is not an unmitigated blessing. Technology creates negative as well as positive impacts. It displaces workers as well as increasing their productivity; it impinges on privacy as well as improving personal exchanges and contacts. In the case of the environment, in particular, the positive contribution of technology is increasingly challenged by its undesirable external effects.
There is evidence that there are limits, at least locally, to the demands we can make on the natural environment to assimilate this multitude of waste products. For example, the natural water flow conditions from the hydrological cycle are often insufficient to maintain adequate water supply to the polluted areas. There are urban areas where adverse climatic conditions do not permit self-cleaning of the atmosphere through wind currents and natural convection. In agriculture, there is a growing body of evidence that the widespread dispersion of chemicals leads to their reappearance in other parts of the ecological system. The increased use of plastic and glass containers leaves a large residue of undegradable waste products which accumulate indefinitely. The imbalance between the rate at which man produces waste products and nature assimilates them drastically changes the nature of the responsibilities of governments. Today a 'laissez-faire' policy of allowing free use of natural resources is no longer possible. Welfare considerations require that governments adopt a policy of deliberate control of human activities in order to preserve the quality of the environment.
The development and diffusion of new technology, with its attendant effect of raising the productivity level, is an essential source of economic growth. It is not possible to assign a precise figure to the contribution of technology to growth because its effects cannot be separated from those of capital investment, education and management. Nevertheless, technological change is widely accepted as an essential element of economic development. Improvements in productivity have ultimate limits which cannot be transcended except through infusion of new technology. No amount of investment or improvements in organization, management or skills, for example, could make the horse-drawn carriage as efficient as a railway. At the same time, technology has enormously increased the range of opportunities open to individual consumers. Advances in communication technology have led to more rapid and more accurate information, advances in transport technology to greater mobility and accessibility to distant places, advances in health technology to less disease, less suffering and greater life expectancy.