the past decade rainfall in widely separate parts of the Northeastern United States and in Scandinavia has been commonly in the range of 3.8 to 5.0, occasionally as low as 3.0 (Likens, et al., 1972).

The high acidity has been correlated with an increase in the amount of sulphate and nitrate in the rain and is thought to be caused by these acid forming ions. The source of the sulphur is thought to be fossil fuels including both oil and coal. The sulphur is oxidized in combustion and forms sulphuric acid in rain. The nitrate is probably fixed by automobiles.

The effects of acid rains are many and important. The acidity is great enough to erode limestone and cement; it is also high enough to affect lakes and streams and to cause serious effects on terrestrial ecosystems including forests, fields, and agriculture.

In southern Norway it is reported that the pH of streams has been lowered to the point of eliminating salmon runs (Klein, 1971). Likens and his colleagues (1972) report data suggesting that the acidity of Lake Michigan, the Illinois River, possibly the Ohio River, and the Mississippi has increased in the last 50 to 75 years. But the most important effects, as yet unmeasured in the United States, are on the uplands. Acid rains leach nutrients from leaves and other tissues of plants. Weak acid is also commonly used to extract nutrients from soils.

A decade or more of highly acid rains must be assumed to have had effects on nutrient cycles in terrestrial ecosystems in the Northeast, including both forests and agriculture. Continued and increasingly acid rain might reasonably be expected, in fact must be expected, to reduce net production of plants regionally making a major step toward the biotic impoverishment of a segment of a continent. A 10 percent to 20 percent reduction in net primary productivity for the region would be difficult to detect in less than several years. Such a reduction may be a reality now; it will be surprising if it is not demonstrated clearly within the next decade. The fact that the effects are diffuse does not diminish their importance. A 10 percent reduction in the net primary production of the vegetation of the New England States would be a loss of solar energy equivalent to the output of 15 1,000 megawatt reactors operating at full capacity.

Solutions to the acid rain problems are elusive. The sources of the sulfur and nitrogen probably extend as far west as Chicago and south to the Gulf States. The possibility of shifting to low sulfur fuels throughout any significant part of this area seems remote in view of the mounting shortage of oil and the shift to coal. An early reduction in the consumption of fossil fuels over the eastern half of the country, however necessary, scarcely appears possible. The prospect for the Northeast is for continued, perhaps increasingly, acid rains that will levy a tax on all, but an especially heavy tax on those who gain their livelihoods directly from forestry, agriculture, fishing or related industries.

It is a most insidious and regressive tax taken from a resource that should not be available for compromise in the endless series of "tradeoffs" made in support of the classical forms of growth. This is a part of the uncounted costs of the growth we have experienced to date that

has led to a nonbiotic energy flux over the U.S. of 1.67 kWh/m2/year. It is one sign that we are overdeveloped-that we not only cannot sustain further growth in the current pattern but must plan now for a substantial revision in the pattern and intensity of our activities. Solar energy is the only long-term source of energy available now for support of man. Most all of the men of the world use it in varying degrees.

Within the next decades we can expect world-wide human demands on the flux of solar energy fixed in photosynthesis to increase with a doubling time of 10 to 20 years, perhaps less. These demands include food, fuel, fiber and environmental services. The demands extend not only to plants, they extend to the full range of diversity of the biota. This diversity offers not only stability and predictability of function, but also a wide range of resources and public services to

man.

The challenge for us is to recognize the dependence of man on the earth's biota and to bend our phenomenal technological resources to see that the biota is not only preserved but that its support for man is enhanced in the most energetically efficient ways consistent with long continued use.

This is not a stance against growth; it is a challenge to redirect growth into new and exciting topics consistent with the facts of a 20th Century Earth headed for 7 billion people in about 30 years. I think certain conclusions are obvious:

First, the Earth's most important resource is its capacity to fix solar energy through photosynthesis and to use it in support of life. This is the Earth's largest flux of energy; its management must now become a major and increasing concern of governments.

Second, man probably uses directly 5 percent to 10 percent of the net primary production of plants, perhaps more in the oceans; the worldwide changes in the quality of air and water and the reductions in the earth's biota indicate that he is using all of the rest of that energy in secondary services and is in effect now mining the life of the earth. Third, man's use of nonbiotic energy has reached about 5 percent of the magnitude or worldwide net production of plants and secondary effects of its use at that level are having serious toxic effects on the earth's biota, probably reducing overall the fixation of solar energy and its availability in support of man.

Fourth, growth in the use of fossil fuels and other energy sources will probably be limited in the next decades by the problems of supply and distribution, forcing major changes in the technological societies that will include restraint of growth in energy-rich technologies.

Fifth, the inevitable struggles for more energy that are intensifying rapidly now should not be allowed to destroy additional segments of the earth's capacity for fixing solar energy. National and international policies on energy development and use are needed now with policies on population, land and water uses to avoid increasing conflict and further degradation of biotic energy sources.

Sixth, the assumption that setting standards for toxins on the basis of thresholds for biotic effects will protect the earth's biota and man is false. There is no way of determining thresholds for the myriad of substances that can be developed and released, no way of controlling

releases, no sure way of monitoring for the substances, and no basis for belief that thresholds for effects on natural ecosystems exist. The alternative is, as stated in the Water Pollution Control Act of 1972, preservation of the chemical, physical and biotic integrity of those areas of the earth not directly manipulated by man for urban or agricultural uses.

Seventh, the assumption that the environment has an assimilative capacity for all human insults is misleading and inconsistent with the imperative that the earth's biota be preserved for continuous use by man. An assimilative capacity for organic matter or heat does not imply an assimilative capacity for mercury, lead or other substances that may accompany the organic matter. The evidence is overwhelming that man has already exceeded the assimilative capacity of the biosphere for CO2, chlorinated hydrocarbon pesticides, PCB's, dust and possibly fossil fuel energy. Assimilative capacity is a useful concept only within those areas of the earth that man determines that he will manage intensively.

Eighth, economic principles are an insufficient basis for management of the biosphere or such large segments of it as the United States controls, insufficient alone. The limits of the earth can be accommodated by recognition of the fact that the biosphere is a series of interacting units, oceans, forests, estuaries, cities, agricultural units, each of which has definable characteristics including interactions with other units. Some, such as the oceans, cannot be managed intensively; others such as cities and agricultural regions, must be.

The design and management of these units is an essential topic for science and government. It is encouraging that our laws are now beginning to reflect in their objectives some of the realities of the biosphere.

Ninth, the pattern of change necessary in the design of human activities is clear and changes are urgently needed. The further diffusion of toxic influences around the globe must be checked. A certain amount of retrenchment and repair is necessary to assure the stability of biotic resources. Cities cannot be allowed to dispose of wastes in the oceans; fresh water supplies, nutrient elements and mineral resources are to be conserved and recycled; estuaries and coastal waters cannot be used for cooling power plants or usurped for other industrial uses: they are essential to maintenance of the oceanic biota, including especially the fisheries.

Tenth, these changes in perspective and function of Government can come only with a major change in objectives, away from the attractive, even beguiling, concept that economic growth will solve all problems and toward a recognition that the earth's basic resources of life and energy are finite. The transition requires major support from science, from the educational establishment, and from legislative bodies. Private enterprise cannot be expected to make these innovations. Government must lead by providing the domestic climate and resources for the massive research and educational needs that such a transition requires.

We are the richest Nation and we should at the moment be building at least two National laboratories, one in the East and one in the West

to address directly the questions of how to reconcile the needs of 20th Century man with the facts of a living but finite earth.

Instead we are watching the dismantling of science. We would be terrified, if we were thoughtful.

Eleventh, the inevitable restriction of growth in energy-dense activities does not restrict growth in all segments of society. On the contrary the problems present an intellectual challenge unprecedented in history. We have now a great new freedom to examine in detail the enduring question of what man's most rewarding circumstances might be. On these topics growth has barely begun.

Thank you.

Senator MUSKIE. Thank you for one of the finest statements it has been my pleasure to hear in 10 years of working with the subcommittee. I wish it could be brought to the attention of every member of Congress.

Dr. WOODWELL. Thank you, Senator Muskie.

Senator MUSKIE. It speaks for itself. It would be almost presumptuous of me to ask questions, but nevertheless, I am.

With respect to measuring the capacities of the oceans, is there a way of measuring the impact of man's activities and how that is adding to the ability of the oceans to continue to serve our needs?

Dr. WOODWELL. Our interests are represented most importantly by the oceanic fisheries. While these are called oceanic, they are concentrated on the coastal shelves. They are heavily dependent on estuaries and marshes along the shores. Perhaps 60 percent of the fisheries are directly dependent in some stage in their life cycle on the estuaries.

I believe we can show that it is essential and will be increasingly essential that these be preserved. This is a source of food for man that would not be replaceable from land easily.

It is important that we recognize that the net primary production of the oceans is fixed. It is the product of algae, very small plants. The energy is passed through a diversity of different organisms to fish. Many of the organisms including the algae that fish feed on are not directly usable by man. If we so simplify the oceans that we reduce fish populations by allowing toxic effects of man to accumulate, we lose the possibility of harvesting this large source of energy. I don't think that the exploitation of the Continental Shelves for production of oil, for example, justifies such a loss.

Senator MUSKIE. Is there a way of making them compatible?

Dr. WOODWELL. There is no way of making them compatible, unless we are willing to exert extraordinary restraints in the exploitation of oil. We can do it slowly, and in a limited way, recognizing that the preservation of the fisheries of Georges Banks is very much more important and vital to man than the extraction of the oil that will in a few years be gone. If we do not use care, the fisheries can be destroyed forever.

Senator MUSKIE. The acceleration of the oil leases by the Federal Government for budget reasons is uneconomical in the sense that it brings about the destruction of these valuable resources. In Maine, we are particularly concerned about the lobster. The catch has been decreased. The catch has shrunk by about 25 percent.

The easiest argument to explain it is that the pressure on the resource for diminution and supply is increased. Is it conceivable that that may also be the result of the kind of things you have been describing?

Dr. WOODWELL. It is certainly conceivable and it is probably true in certain localities that it is. However, I think the decline in lobster yields is pretty widely agreed on by fisheries biologists as being due primarily to over-exploitation.

Senator MUSKIE. In your statement you touch upon two of the most controversial issues that stand between us and the effective implementation of our laws to deal with air and water pollution; the assimilative capacity of the environment, for one, and then the aversion of economic principals as a basis for managing our use of our natural resources. Both of these are involved in the issue involved in the clean car, for example.

I am delighted that so much of your statement touches upon that issue. I wondered with respect to the assimilative capacity of the atmosphere, whether you could give us further insight.

It is easy, I think, for the automobile manufacturers to argue and easy for many people to believe that the dispersion of these gaseous pollutants into the air does not have an accumulative effect.

I wonder if you could touch upon that. We would like to have something in this record to use later this year.

Dr. WOODWELL. The atmosphere cannot be considered separate from the biota of the land or the biota of the ocean. The atmosphere is closely coupled through precipitation to the oceans and the land. Anything that is released into the atmosphere has the possibility of being rained out on the land in places where it may be very directly important to man or rained out into the oceans where it may be indirectly very important to man. I have great difficulty in separating the assimilative capacity of the atmosphere from the assimilative capacity of the rest of the earth.

Lead is a good example. There is not very much doubt that lead released into the atmosphere in automotive exhausts is deposited very close to highways and is now reaching high levels in the soil. What its effect upon plants is and has been in those regions have not been fully studied.

The atmosphere has a certain dependency for its assimilative capacity on forests; air passing through forests is, indeed, cleaned by forest. Particulate matter is removed from the air. There are exchanges of carbon dioxide and other gases with the biota.

The reduction of forests by accumulative insults through the atmosphere-and this is occurring, as we know throughout the Los Angeles Basin right now-aggravates the problem. I think that there isn't any question that we have to take a very hard line on further releases into the atmosphere, whether it be through automobiles or through industrial releases.

Senator MUSKIE. Senator Clark, do you have any questions?

Senator CLARK. I certainly share the chairman's admiration for your paper. It is obviously very clearly written and thought through. Although the thrust of your paper is not the energy crisis, it is one of the major considerations before the Congress. It might well be that