In December of 1978, the NADP submitted a report to the Council on Environmental Quality, at their request, entitled "A National Program for Assessing the Problem of Atmospheric Deposition." i

As you know, there is an interagency committee now formulating a Federal acid rain assessment plan, and we had the opportunity to prepare the original draft national plan which was used as a basis for President Carter's initiative which he announced last August in his second environmental message.

I was interested in your remarks, Senator Tsongas, with regard to this relationship between energy policy and the quality of our environment.

We say, on page 55 of that particular report to CEQ.

If the United States is to so greatly augment the amounts of substances dispersed in the atmosphere and deposited into the biosphere of the earth, it is essential that we should measure the amount and chemical form of the deposited matter and understand the biological consequences of that deposition.

That sentence says, in essence, what you said just a few moments ago.

So, in that report to CEQ, we tried to outline what we felt would be a suitable interagency approach to the acid rain problem.

Many of the ideas that are presented in my written testimony are developed more fully within the pages of that report to CEQ. You also have expressed in the hearing agenda an interest in the history of acid rain, and I completed a historical analysis of the development of public and scientific understanding of that subject not long ago for the action seminar on acid precipitation which was held in Toronto. And copies of that are also available for your staff. The major points of my testimony can be summarized very briefly, and I will read a section from page 2 and onto page 3.

Acid rain has become a dominant feature of man-induced change in the chemical climate of the Earth. But the increasing acidity of rain is only part of the changing chemistry of precipitation, dry particulate matter, aerosols and gases in the major industrial nations of the world.

We call the deposition of all these four forms of substance atmospheric deposition. Acid rain is only a part of that phenomenon. Recent biological research on acid precipitation has demonstrated several things: First, atmospheric deposition contains both beneficial nutrients and injurious substances; second, plants, animals, and ecosystems vary a great deal in their susceptibility, tolerance, and adaptability to changes in atmospheric deposition; third, injury is most likely when rapid changes in the chemical climate coincide with a vulnerable life form or life stage; fourth, increasing acidity of precipitation has caused extinction of fish and other changes in species composition at all topic levels, all sorts of biological organisms in oligotrophic lakes in northern Europe and eastern North America; and, fifth, simulated acid rain has caused leaching of nutrients from soil and both direct and indirect injury to terrestrial vegetation. With rare exceptions, however, economic damage to crops by naturally occurring acid rain has not been demonstrated to date.

1 See appendix I.

These very preliminary results show why the comprehensive acid rain assessment program called for by the President in his second environmental message is so crucially important in maintaining the quality of surface waters, the health of fish, and the productivity of forests, agricultural crops, and range lands in this country and Canada.

I think it is awfully important that we understand, though, the present inadequacies of our understanding of many aspects of both atmospheric chemistry, atmospheric transport, atmospheric deposition, and the biological and other effects of acid rain both in the aquatic and in the terrestrial areas.

On the bottom of page 3, I have made two statements which summarize my own general understanding of where I think we stand today with regard to this issue in the context of your hearings about energy policy.

As of May of 1980, the effects of acid precipitation and associated metal ion toxicity on aquatic ecosystems are sufficiently well known and sufficiently serious that preliminary formulation of energy conservation, regulatory and ameliorative policies can be initiated now.

As of this same month, however, potential effects on terrestrial organisms are still too poorly understood to permit the development of wise regulatory policies at this time.

Senator TSONGAS. What does that mean?

Dr. COWLING. That we don't know enough about the effects on forests or on agricultural crops to know if acid rain is having important economic influences on either forests or crops.

Senator TSONGAS. The oil backout bill that is before the committee to be marked up tomorrow, one of the issues is whether we should require converting powerplants to keep their levels of emissions constant.

What would your position be on that?

Dr. COWLING. I'm afraid I did not understand. It is on emissions, you say?

Senator TSONGAS. Constant emissions. So that, as you convert the coal, that you put in place the scrubbers or whatever is necessary to not increase the emissions.

Dr. COWLING. I think it is very clear that a constant rate of emission of oxides of sulfur and oxides of nitrogen would continue to cause losses in aquatic life in this country.

It may also and I emphasize "may" because we don't understand the effects on forests or agricultural crops yet sufficiently to be able to say whether those constant emissions are now or whether they will in the future cause economic damage to agriculture and forestry in this country.

It is my personal belief that they probably will, but we do not have the hard scientific evidence to make that judgment on the terrestrial side at the present time.

Senator TSONGAS. The issue before the committee, unfortunately, is not between constant emissions and less emissions, but between constant emissions and greater emissions. Just to put your mind at rest, that is still where we're at.

Dr. COWLING. I think it is very important, and in terms of our present understanding and the question of public perception of

importance may be different than our present scientific understanding.

It appears to me that the public is ahead even of Mr. Costle on this issue at the present time. The public is not anxious to see aquatic ecosystems suffer.

Senator TSONGAS. One of the things I was taught in law schools is to never ask a question if you don't know what the answer is going to be but, at that risk, let me ask you this.

In the markup that is going to take place tomorrow, would you endorse or not endorse the policy that the conversion to coal should not take place if there is going to be a greater amount of emissions in the atmosphere?

Do you, in essence, endorse a policy of constant emissions?

Dr. COWLING. Let me say, first, that I am, of course, a scientist and not a politician. And it is my duty to provide you with the scientific assessment of the facts, and I guess it is the duty of the politician to make decisions.

I can only say that I am a specialist in the area of biological effects, and I am a layman in everything else.

As a layman, I can answer your question. And as a layman, I would say that I would favor no increase in emissions.

Senator TSONGAS. If I gave that answer, it would be called a political answer but, I suppose, if you give it, it is a scientific answer. So-

Dr. COWLING. I think it is important that scientists join together with politicians in placing at your disposal the important facts as we understand them.

And I think it is the responsibility of the politician to respond to his perception of public interest, which is a much larger subject than the science which we

Senator TSONGAS. But I think it is very helpful to have a situation where you could indicate, if you sat in this seat and you had to vote, how you would vote.

Dr. COWLING. It is very clear how I would vote.

Senator TSONGAS. All right. That is why I am trying to get at. Dr. COWLING. But I would have to say that in my capacity as a layman.

Senator TSONGAS. Well, you get one vote whether you are a layperson or a scientist. [Laughter.]

Senator DOMENICI. Where is he going to run?

Senator TSONGAS. I think in New Mexico.

Senator DOMENICI. You get one vote.

Senator TSONGAS. Why don't you continue, Dr. Cowling.

Dr. COWLING. The only additional remarks I had intended to make is simply to call attention, again, to item 4, which is an attempt on our part to provide, in a very few sentences, the essence of what we know about this phenomenon and its effects.

And I should like just to make a few remarks about terrestrial ecosystems, and then I should like to turn the microphone over to George Hendrey, who is prepared to illustrate some changes in emissions patterns and to comment about aquatic ecosystem effects.

Senator TSONGAS. If you could read through pages 4 and 5, I think it would be valuable to have some of that read into the record.

Dr. COWLING. OK. Page 4 begins a section entitled "Acid Precipitation as Part of a General Phenomenon of Atmospheric Deposition."

I am glad you asked me to do this because this is one of the most important issues that I think occurs. Acid precipitation is a general term understood by the public, but atmospheric deposition is what we must be concerned about regulating in this country.

Precipitation formed in an atmosphere relatively free from natural or anthropogenic sources of contamination would have a pH of about 5.6 due to dissolution of gaseous CO2. Thus, acid precipitation has been defined operationally as rain or snow with a pH value below 5.6.

But acidity in precipitation must be understood as a reflection not only of the amounts of substances yielding hydrogen ions, such as sulfuric, nitric, hydrochloric or organic acids, but also of the total ionic balance between all the cations and anions in precipitation.

Cations are things with positive charges, and anions are things with negative charges, chemically.

Most of the substances dispersed in the atmosphere are at least partially soluble in water. These dissolved substances can be absorbed or assimilated by plants when precipitation is intercepted by vegetation.

Since some of the substances dissolved in precipitation are beneficial while others are injurious to plants and animals, the net effect of atmospheric deposition can be beneficial or injurious depending upon the chemical composition of the deposited matter, the duration and intensity of deposition episodes, the species and genetic characteristics of the organisms on which the substances are deposited, and the physiological condition, structure, development, and stage of maturity of the organisms.

Direct injury to living organisms by acid precipitation is most likely when a particularly vulnerable life form-for example, a lichen or a fish-is exposed at a particularly vulnerable life stagefor example, at an early stage of reproduction-and are growing in a poorly buffered environment-for example, sandy soils or oligotrophic lakes or bogs-during a season of the year when acid precipitation is most likely-for example, during spring rains.

Rain and snow change in chemical composition within as well as between precipitation events. In cold climates, acid substances accumulate in the snowpak where they are released in concentrated form with the first melt water and, thus, cause very sudden increases in acidity of soils, vegetation, and surface waters.

Thus, a given organism or ecosystem may be subject to beneficial atmospheric influences at one time and to negative influences at another time within a given day, month, growing season, or the years of its development in the case of perennial plants and animals.

Even a given molecular species such as SO2 or NO, may be absorbed and utilized as a beneficial nutrient at one concentration; at another, higher concentration, however, even on the same day,

the same substance may be absorbed and found to be toxic or even injurious to the very same plant, animal, or microorganism.

Did you want me to read further?

Senator TSONGAS. That is fine. I want to read you a paragraph and, if you could respond to it, then I would yield to the Senator from New Hampshire for a statement:

In the Eastern United States, the average pH of rainfall is now between 4 and 4.5. and your statement refers to 5.6 as normal.

Dr. COWLING. Yes.

Senator TSONGAS. [continuing].

An increase of about 50 times in the last 25 years. Some rainfall has been reported at pH levels as low as 3, almost equivalent to the acidity of lemon juice or vinegar. Acid rain not only appears to be spreading in severity, but also in aerial extent. In 1955-56, an area where rainfall was reported to be below a 4.6 pH level was located in parts of Ohio, Pennsylvania, West Virginia, New York, and New England, precisely where sulfur dioxide emissions were highest. By 1975-76, the area with an average pH below 4.6 had extended as far west as the Mississippi River, as far south as Florida.

Do you concur with that statement?

Dr. COWLING. Yes, I do. And that statement is supported by the research work of many scientists. The Likens contribution is especially often cited.

But I think the latest issue of Science, this came out just yesterday, contains evidence of a 25-year major difference in Florida in terms of precipitation.

So, I would simply like to add to the statement as you read it that we now are having quite an array of evidence that changes are taking place in the acidity of deposition.

And I think that you will no doubt hear testimony later today which draws into question the rigor with which we can make those assertions, and particularly in the context of the time period between 1955 and the present.

I must say that the question of whether it was in 1940 or 1955 or in 1850 that we ought to be making our comparisons-the point is that man's activities, largely related to increasing combustion of fossil fuels, are changing the chemical climate of the Earth and are changing increasingly large regions of the chemical climate of the Earth.

Senator TSONGAS. I will insert in the record the Science article you referred to, as well as the CEQ report.1

[The prepared statement of Dr. Cowling and material referred to above follow:]