The city is an ecosystem and as such it functions in the same way that other ecosystems do, which is through energy transformation. The natural ecosystem transforms the energy of the sun. The primary producers of natural ecosystems capture sunlight energy and, in the environment of a warmed and heated earth, light and dark reactions of photosynthesis occur.

This basic process produces most of the food of the plants and animals on earth. The energy of sunlight is captured in the plants and chemically stored as food. This food, the protein, carbohydrate, and fat of metabolism, constitutes a universal energy storehouse for animals and non-green plants; they are all dependent upon it.

The more diversification in the ecosystem, the more ways sunlight energy will be trapped, and the more ways the food will be consumed and converted into protoplasms of the organisms of the food chain. Most simple communities cannot efficiently use the vast quantities of energy that fall upon them and are forced to diversify and become more complicated. Excess food always paves the way for population and species increases. A mature community that is highly developed can utilize large quantities of energy, transform it into the many elements of the complex system, and in so doing stabilize itself enormously.

The natural ecosystems of the earth that have the greatest productivity, i.e., the ability to use energy, have the greatest complexity. In terrestrial environments they are forest communities with their many layers of photosynthetic receptors. These communities provide the greatest number of niches for animals and non-green plants that depend upon the chemical energy of food fixed in photosynthesis.

In marine environments, which are the most productive on earth, light penetration to a depth of about 600 feet results in photosynthesis and a great diversity of organisms, which in turn result in highly diverse and productive communities. The waters of the estuaries and the coral reefs abound with the diversity of photosynthetic producers and non-green plant and animal consumers.

The communities of man are consumers and transformers of energy. The rise of technology is the rise of the utilization of energy: first that of man himself; then of hand tools and draft animals; and finally of mechanized tools—steam and internal combustion engines, electrical motors, physical, chemical, and nuclear energy.

During the rise of technology, man developed cities where the work is done and where energy conversion occurs. With the transportation of materials, fuels, and energy, the cities have become the principal places of energy utilization. The simpler the city, the less need it has for energy. The more complicated the city, the more energy it will use. The more diversified the energy sources, the more stable the system; the fewer sources of energy, the less stable.

The power grids of the nation are rapidly becoming one. The New York City power blackout occurred because the system was dependent upon relatively few alternative methods of transmission. Once the grid system broke down, large sections of the northeast were blacked out, with serious consequences. Ecologically, it was a lack of redundancy that contributed to the failure of transportation of power to cities.

Redundancy is a major ecological factor in ecosystem stability. The power grid, if it is to remain effective as it grows and encompasses all of the United States, must be many power grids. It must have redundancy built in every conceivable way so that if one part of the system fails, other portions will automatically continue to function.

The history of the city as the transformer of energy illustrates the congruity of the city and other natural ecosystems. As the cities have increased in complexity they have done so because of increased knowledge of energy transportation—mechanical, chemical, physical, and nuclear. An analysis of energy utilization and the effects of energy utilization upon the stability of ecosystems provides the only logical basis for technology assessment.

In studying the achieving society, electrical energy production is used as the index of achievement. Highly developed nations have high energy production and consumption. Those with the greatest energy consumption also consume the greatest amount of the world's raw products. In evaluating technology, the most important question is: What is technology, old or new, doing to the natural ecosystem of the world? For centuries there was little concern for ecosystem degradation, whether of man or nature, but recent trends in technology have resulted in instability and degradation of the human as well as the natural ecosystems that threaten the very existence of technological man.

The vast consumption of energy needed to power individual automobiles is wasteful. In terms of efficiency of use the automobile not only wastes energy because its energy converting process is inefficient, it also pollutes and degrades the environment and disperses the human community. Water, electricity, gas, and sewage disposal become inordinately expensive due to the low density of the population served.

High speed transportation can and does have effect upon human ecosystems by a stabilizing easing the rate and amount of goods and people moving in the course of business. The automobile is self-defeating and detrimental when it is made the basis of transportation in the neighborhood communities of man, for it distorts the community out of proportion to the size and energy capability of man himself. Moreover, it has a tendency to inhibit the movement of the non-driver—the aged, the young, and the infirm. Telephone communication knits together the community and is a stabilizing influence.

Pesticides simplify ecosystems making them prone to invasion by unwanted organisms. This disadvantage must be weighed against the possible gains. Pesticides bring about a reduction of ecosystem diversity and the stability that is the hallmark of ecosystem health. The effects of technology can be measured against that standard.

The computer, the extension of man's brain, is capable of processing the voluminous data that must be evaluated, and the computer is ready and waiting. We need to understand that technology assessment is an ecological problem. Specifically, it is the problem of evaluating the use by man of energy and the effects of that energy upon the ecosystems; the primary one of these is the city.

—Theodore W. Sudia