The Condition of the

There is little question about the harmful effects of ozone depletion, acid rain, or the greenhouse effect. One might debate if the prime cause of desertification is acid rain, ex

FIG. 2 Areas of diminishing rain forests and spreading deserts.

cessive lumbering, soil erosion, or changes in the weather, but it is a fact that the rain forests are diminishing and the deserts are spreading (Figure 2). We do not know what quantity of acid fumes, fluorinated hydrocarbons, or carbon dioxide gases can be released before climatic changes become irreversible. But we do know that the carbon dioxide content of the atmosphere has substantially increased, that each automobile releases 5 tons of carbon dioxide every year, and that the number of gas-burning oil platforms in the oceans is approaching 10,000.

Conditions on the land and in the waters are determined by complex biosystems. The nonbiological nature of air makes the setting of emission standards and their enforcement somewhat easier. As discussed in Chapter 5 of this handbook, the United States has air quality and emission standards for particulates, carbon monoxide, sul fur and nitrogen oxides, hydrocarbons, photochemical ox-idants, asbestos, beryllium, and mercury.

For other materials, such as the "possible human carcinogens, " the furans and dioxins (PCDD and PCDF), there are no firm emission or air quality standards yet. These materials are the byproducts of paper bleaching, wood preservative and pesticide manufacturing, and the incineration of plastics. Because typical municipal solid waste (MSW) in the U.S. contains some 8% plastics, incineration is probably the prime source of dioxin emissions. Dioxins are formed on incinerator fly ash and end up either in landfills or are released into the atmosphere. Dioxin is suspected to be not only a carcinogen but also a cause of birth defects. It is concentrated through the food chain, is deposited in human fat tissues, and in some cases dioxin concentrations of 1.0 ppb have already been found in mother's milk.

An essentially "linear" or open materials economy. The objective is to increase annual production (GNP) by maximizing the flow of materials. The natural pressure, therefore, is to decrease the life or quality of the items produced.

A circular or closed materials economy. Limits on the total amount of materials or wealth will depend upon the availability of resources and energy and the earth's ecological, biological and physical system. Within these limits, the lower the rate of material flow, the greater the wealth of the population. The objective would be to maximize the life expectancy and, hence, quality of items produced.

A circular or closed materials economy. Limits on the total amount of materials or wealth will depend upon the availability of resources and energy and the earth's ecological, biological and physical system. Within these limits, the lower the rate of material flow, the greater the wealth of the population. The objective would be to maximize the life expectancy and, hence, quality of items produced.

FIG. 3 The "open" and "closed" material-flow economies.

Although in the last decades the air quality in the U.S. improved and the newer standards (such as the Clean Air Act of 1990) became stricter, lately we have seen misguided attempts to reverse this progress. Regulations protecting wetlands, forbidding clear-cutting of forests, and mandating use of electric cars have all been relaxed or reversed. In the rest of the world, the overall trend is continued deterioration of air quality. In the U.S., part of the improvement in air quality is due not to pollution abatement but to the exporting of manufacturing industries; part of the improvement is made possible by relatively low population density, not the result of conservation efforts.

On a per capita basis the American contribution to worldwide pollutant emissions is high. For example, the yearly per capita generation of carbon dioxide in the U.S. is about 20 tons. This is twentyfold the per capita CO2 generation of India. Therefore, even if the emission levels in the West are stabilized or reduced, the global generation of pollutants is likely to continue to rise as worldwide living standards slowly equalize.

The Condition of the Land

Nature never produces anything that it can not decompose and return into the pool of fresh resources. Man does. Nature returns organic wastes to the soil as fertilizer. Man often dumps such wastes in the oceans, buries them in landfills, or burns them in incinerators. Man's deeply rooted belief in continuous growth treats nature as a commodity, the land, oceans, and atmosphere as free dumps. There is a subconscious assumption that the planet is inexhaustible. In fact the dimensions of the biosphere are fixed and the planet's resources are exhaustible.

The gross national product (GNP) is an indicator based on the expectation of continuous growth. We consider the economy healthy when the GNP and, therefore, the quantity of goods produced increases. The present economic model is like an open pipeline which takes in resources at one end and spills out wastes at the other. The GNP in this model is simply a measure of the rate at which resources are being converted to wastes. The higher the GNP, the faster the resources are exhausted (Figure 3). According to this model, cutting down a forest to build a parking lot increases the GNP and is therefore good for the economy. Similarly, this open-loop model might suggest that it is cheaper to make paper from trees than from waste paper, because the environmental costs of paper manufacturing and disposal are not included in the cost of the paper, but are borne separately by the whole community.

In contrast, the economic model of the future will have to be a closed-loop pipeline (Closed-GNP). This will be achieved when it becomes more profitable to reuse raw materials than to purchase fresh supplies. This is a function of economic policy. For example, in those cities where only newspapers printed on recycled paper are allowed to be sold, there is a healthy market for used paper and the volume of municipal waste is reduced. Similarly, in countries where environmental and disposal costs are incorporated into the total cost of the products (in the form of taxes), it is more profitable to increase quality and durability than to increase the production quantity (Figure 3).

In addition to resource depletion and the disposal of toxic, radioactive, and municipal wastes, the natural environment is also under attack from strip mining, clear cutting, noise, and a variety of other human activities. In short, there is a danger of transforming the diverse and stable ecosystem into an unstable one which consists only of man and his chemically sustained food factory.

Energy

When man started to supplement his muscle energy with outside sources, these sources were all renewable and inexhaustible. The muscle power of animals, the burning of wood, the use of hydraulic energy were man's external energy sources for millions of years. Only during the last couple of centuries have we started to use exhaustible energy sources, such as coal, oil, gas, and nuclear. This change in energy sources not only resulted in pollution but has also caused uncertainty about our future because we can not be certain if the transition from an exhausted energy source to the next one can be achieved without major disruptions.

The total energy content of all fossil deposits and uranium 235 (the energy source of "conventional" nuclear plants) on the planet is estimated to be 100 X 1018 BTUs. Our present yearly energy consumption is about 0.25 X 1018 BTUs. This would give us 400 years to convert to an inexhaustible energy source, if our population and energy demand were stable and if some energy sources (oil and gas) were not depleted much sooner than others.

Breeder reactors have not been considered in this evaluation because the plutonium they produce is too dangerous to even contemplate a plutonium-based future. This is not to say that conventional nuclear power is safe. Man has not lived long enough with radiation to know if millions of cubic feet of nuclear wastes can be stored safely.

We receive about 100 Watts of solar energy on each square meter of the Earth's surface, or a yearly total of about 25 X 1018 BTUs. Therefore, 1% of the solar energy received on the surface of the planet could supply our total energy needs. If collected on artificial islands or in desert areas around the Equator, where the solar radiation intensity is much higher than average, a fraction of 1% of the globe's surface could permanently supply our total energy needs. If the collected solar power were used to obtain hydrogen from water and if the compressed hydrogen were used as our electric, heat, and transportation energy source, burning this fuel would result in the emission of only clean, nonpolluting steam. Also, if the combustion took place in fuel cells, we could nearly double the present efficiency of electric power generation (about 33%) or the efficiency of the internal combustion engine

FIG. 4 Growth of human population.

(about 25%) and thereby substantially reduce thermal pollution.

Today, as conventional energy use increases, pollution tends to rise exponentially. As the population of the U.S. has increased 50% and our per capita energy consumption has risen 25%, the emission of pollutants has soared by 2000%. While the population of the world doubles in about 50 years, energy consumption doubles in about 20 and electric energy use even faster. In addition to chemical pollution, thermal pollution also rises with fossil energy consumption, because for each unit of electricity generated, two units of heat energy are discharged into the environment.

It is time to redirect our resources from the military— whose job it is to protect dwindling oil resources—and from deep sea drilling—which might cause irreversible harm to the ocean's environment—and use these resources to develop the new, permanent, and inexhaustible energy supplies of the future.

Solar Panel Basics

Solar Panel Basics

Global warming is a huge problem which will significantly affect every country in the world. Many people all over the world are trying to do whatever they can to help combat the effects of global warming. One of the ways that people can fight global warming is to reduce their dependence on non-renewable energy sources like oil and petroleum based products.

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