Threats From Above

Some recently perceived threats to environmental quality and human health and safety seem almost the stuff of science fiction: inexorably rising global temperatures, poison rain, and increasing incidence of skin cancer caused by ultraviolet light all have an otherworldly aspect to them, a quality that sometimes strains the credulity of a public increasingly skeptical about unseen risks of disaster.

Yet global warming caused by the accumulation of carbon dioxide in the atmosphere, acid rain, and depletion of the protective stratospheric ozone shield are real problems, despite significant uncertainties about each of them, and they deserve serious study and evaluation. Perhaps what is most important, they require sustained international cooperation for their amelioration, and it is not at all clear that U.S. or other national leaders are prepared to deal with these issues either soon or effectively.

Taking advantage of the presence at Resources for the Future of visiting scholar John W. Firor, RFF produced a radio program on atmospheric problems for the FOCUS public affairs series featuring Firor and Paul R. Portney and moderated by Harry B. Ellis. FOCUS is the product of a consortium of seven Washington nonprofit organizations and is headquartered at RFF. "Focus on Threats from Above" was aired during June on some two hundred public radio stations throughout the United States.

John Firor, a physicist, is director of the Advanced Study Program of the National Center for Atmospheric Research in Boulder, Colorado, and formerly was NCAR's executive director. Economist Paul Portney, a senior fellow in RFF's Quality of the Environment Division, spent two years as senior economist at the President's Council on Environmental Quality during the Carter administration. Harry Ellis is deputy chief of the Washington bureau of the Christian Science Monitor and frequent panelist on the PBS television show, "Washington Week in Review." The following article is an edited transcript of the radio discussion.

ELLIS: Gentlemen, to a certain extent human beings can change their environments: they can move from, say, a cold climate, and often are concerned if they think that their immediate environment is being damaged by deforestation, strip-mining, or the like. But perhaps relatively few of us look beyond our immediate environment to the atmospheric envelope that encases our earth and is the heritage of all living creatures. I'd like to discuss with you three atmospheric problems which may portend changes that fundamentally would affect all of us. We'll concentrate on climate change through the increase of carbon dioxide in the atmosphere, caused partly by the burning of fossil fuels; ozone depletion, which may add to the damage caused by carbon dioxide increase; and the emergent problem, at least to laymen, of acid rain. To begin, how conclusive is the evidence for changes in the atmosphere?

FIROR: It's variable over the three problems you mentioned. I think the consensus among experts is that acid rain is indeed happening—there's no doubt that the origin is anthropogenic, that the sulfur dioxide and nitrogen oxides we people put in the atmosphere end up as the acid-forming component.

Hence, the details that need to be worked out are not what is occurring, but exactly how, and how much, and what steps we might take to ameliorate it.

The ozone problem is perhaps one step less certain. I think the theoreticians believe they have a perfectly credible story about how fluorocarbons damage ozone.

ELLIS: Can you define fluorocarbons for us?

FIROR: Well, there is a sequence of compounds with a carbon atom, surrounded either by several chlorine or fluorine atoms. These compounds are very stable, and very useful: they used to be found in all our spray cans, and they still are used in all our refrigerators, but when they get to the stratosphere they are broken down by sunlight and free chlorine then enters a complicated reaction that destroys ozone. And that has led to some worries about more ultraviolet light coming in through the stratosphere—entering through the ozone screen that used to keep it out—and doing damage on the surface of the earth, in particular through increased incidence of skin cancer and, hypothetically, through damage to plants. We do not know exactly how it might hurt plant life, but it's hard to imagine that plants would not be sensitive to more ultraviolet light.

ELLIS: And climate change through the increase of carbon dioxide in the atmosphere? Would you define the problem for us and then give us an idea of how urgent it is?

FIROR: The greenhouse effect. That, of course, is the biggest one of all, and on a scale of certainty, perhaps the least certain of the three. It's fairly simple in concept. Each year we put more carbon dioxide into the atmosphere, mostly by burning fossil fuels, as you said. This carbon dioxide stays in the atmosphere for a very long time—maybe a thousand years, because the ways it's removed from the atmosphere are slow. While it is in the atmosphere it traps heat—the so-called greenhouse effect. The sunlight coming in warms the surface, the heat trying to get out is blocked by carbon dioxide, and hence the earth warms up. So the forecast is that, as we continue year by year to increase the total carbon dioxide burden of the atmosphere, the earth will, in time, respond by getting warmer and warmer.

There's no measurement right now that speaks directly to the problem except the fact that carbon dioxide is increasing in the atmosphere every year. But the projected impact of that change in carbon dioxide is global, it's slow—it occurs in the next decade, or the next three decades—and there are no measurements now that say, yes, it's happening. So the problem as such still has to be considered in the realm of a calculation: there is lots of evidence to suggest that yes, it's real, but you cannot promise it's going to happen.

ELLIS: Dr. Portney, would you tip the scale of risk a bit differently than Dr. Firor does?

PORTNEY: I don't think so, but I might add that, in the case of carbon dioxide, one of the reasons that there is so much uncertainty about whether the buildup of carbon dioxide in the atmosphere is affecting temperature is that there are long swings in temperature that occur independently of carbon dioxide concentration and, in fact, shorter swings that still may take ten or twenty years to work themselves out. So that the world could be on a downward, twenty-year swing, during which time an increase in carbon dioxide might raise temperatures above the level they would be normally, but it would not be noticed because temperatures would be colder than twenty years ago.

The problem is that if you disregard upward tendencies during downward swings, when there is an upward swing— arid, in fact, the atmosphere has been warmed because of the presence of carbon dioxide—temperatures may climb far above the highest point that the globe has seen for awhile. That is why this is such a dangerous problem: It's hard to detect, it gets mixed up with shorter and longer swings, and it may be happening even during a period when general temperature conditions appear to be getting colder.

Irreversibility

ELLIS: Is a part of the danger the fact that these changes, indeed if they are occurring, are irreversible?

FIROR: Eventually carbon dioxide would disperse if we quit pumping more into the atmosphere, but that "eventually" is a thousand years, so that as far as any planning horizon that we use in this life is concerned, it's permanent; it's irreversible.

The other two problems—ozone depletion and acid rain—I think are reversible on a decadal scale: if you quit putting something into the atmosphere now, it will clear itself up in a decade or two. But carbon dioxide mixes with the ocean; oceans are very slow to change, and it's going to take a long time to change the amount of carbon dioxide in the atmosphere.

ELLIS: Dr. Firor, how much evidence is there of actual warming of the atmosphere due to carbon dioxide and, second, are there benign causes of an increase—benign in the sense that they are wholly natural increases, and how much of it is due to the fact that, all in a rush, so far as history is concerned, humans are burning fossil fuels?

FIROR: How much evidence is there that we have actually warmed? The forecast of warming—the theoretical forecast that evidence of warming should become visible perhaps a decade from now there is no present measurement that contradicts the theory, but there is none that supports it either. It's supposed to be a slowly changing event.

On "benign" causes: people digging down into glaciers have found ice that occurred at a datable time, say, in the last Ice Age, and have analyzed that ice for dissolved carbon dioxide. And sure enough, there was a lot less carbon dioxide during the Ice Age than there is now. Some ice has been found from a period of time called the altithermal, back in the Bronze Age, when it was somewhat warmer than it is today, and that seems to show a little more carbon dioxide. So there is circumstantial evidence that ties carbon dioxide to climate. But we do not know whether that is cause or effect; it could be either. So we are still putting together as much evidence as we can to try to make a coherent story.

Policy complications

ELLIS: Dr. Portney, the layperson might ask, What are the consequences of warming? Why should we be concerned with it?

PORTNEY: That's a very good question, because it points to the reason why making policy—even if the scientific uncertainties could be eliminated—is going to be very difficult. One does not have to be a meteorologist to know that in certain areas a little warming would be seen as a good thing.

One of the economic consequences of climatological change would be shifts in cropping patterns; for example, some areas would experience a lengthening of the growing season; this would be partially offset by desertification in other areas. Places that were favorable to crop growing might find that it's either too hot or the pattern of precipitation has been changed in such a way that, at the very least, more irrigation would be needed.

And one of the most worrisome aspects of potential climate change—though one of the most speculative—has to do with the possible melting of the polar ice caps. If—and I want to emphasize if—the period of warming were sustained enough and if the polar ice caps began to melt, it might significantly affect sea level and, consequently, coastal areas. Some predictions have had sea level rising by as much as 5 meters if warming were sustained over a long time. Well, this obviously has severe implications for those who live close to the sea. Since people tend to cluster near coasts, it would mean the inundation of heavily populated areas in large parts of the United States and in other maritime nations.

FIROR: To a degree, we can look historically at these problems that Paul's talking about. There was a period during the twelfth century when it was a bit warmer than it is now. That was the period of the great Viking exploration of the North Atlantic, characterized by colonization and the creation of communities in Greenland, for example. That was brought to a rather abrupt end by the onset of a slightly cooler period, known to climatologists as the Little Ice Age, when you couldn't sail the North Atlantic in primitive craft, and trade routes were disrupted.

To some extent we can use as a model of what might happen the smaller climate changes of the past. So our laboratory at the National Center for Atmospheric Research is working very hard to reconstruct the period of four to six thousand years ago, when it was somewhat warmer than now—warmer even than it was in the twelfth-century period—to see what we can tell about how it will be when carbon dioxide warms us up.

ELLIS: It seems to me that here we are entering a problem area. On the one hand, we know that the increased burning of fossil fuels contributes to the problem, but under President Reagan's administration, there is a thrust toward producing more fossil fuels—natural gas, coal, and oil—and a lessening of the budgets for solar and renewable resources. This would seem a risky proposition, and yet if there is no conclusive evidence, how does one persuade policymakers of it?

PORTNEY: You have touched on an interesting point. On the positive side, one has to remember that a keystone of the administration's energy proposals has been the complete decontrol of crude oil prices, and this has had the commendable effect of discouraging profligate energy use: fossil fuel combustion is discouraged as the price goes up. So while it's true that the budget shift away from such sources as solar energy, windpower, and geothermal may push us in the direction of more fossil fuel use, with the possible outcome that we may be exacerbating the buildup of carbon dioxide in the atmosphere, I think we do have to keep in mind that the de-control of crude oil, and the possible de-control of natural gas, may act to dampen overall energy demand. What will be the net effect of deemphasizing solar and renewable energy sources, coupled with decontrol of crude oil and natural gas prices, I can't say, but it's not as if all of the signs point in the direction of more fossil fuel combustion.

Fossil fuel differences

FIROR: There is another aspect, and that is that all fossil fuels are not the same in their capability of producing heat and carbon dioxide in a fixed ratio. Natural gas, for example, produces a relatively large amount of heat for each ton of carbon dioxide put into the atmosphere, because by and large the heat comes from the hydrogen rather than the carbon in the molecule. The other end of the spectrum is held down by the so-called synfuels, which produce a good deal of carbon dioxide merely in their creation, in their processing, and then even more when they are burned. So natural gas is a much more favorable fuel than synthetic fuels if you are trying to decrease the amount of carbon dioxide you are putting in the atmosphere. Coal is intermediate. Coal is pure carbon, so it's straightforward in that every time you burn it you produce carbon dioxide.

It seems to me that the strategy we have to engage in—in the light of the uncertainty we have emphasized—is a many-part strategy. There is no way that we scientists can come to the decision makers of the world and say, "We think there's going to be a carbon dioxide problem, so quit burning fossil fuels." Everybody would laugh. Correctly. Because fossil fuels are too fundamental to everything that we do.

Therefore, if you cannot find a complete solution to a problem, you have to find ten 10-percent solutions, or partial solutions. And it seems to me what we need to do first is to slow down the use of fossil fuels wherever we can, by replacing them with renewable sources, or non-carbon-dioxide-producing sources. This will give us more time to work. And second, we should learn how to live with a warmer climate, so that we can move more gracefully into such a period when and if it comes. This strategy involves doing lots of different things. Afforestation makes sense, for example, because forests eat up carbon dioxide and that helps lengthen the time before we get into trouble.

Spray cans and ozone depletion

ELLIS: Gentlemen, I would like to shift our focus just a bit. Another problem on which scientists have approached policy-makers is ozone depletion. To the layperon, it seemed mostly an argument that one should no longer use a spray can for shaving cream or deodorant. Now fluorocarbon sprays are banned, and yet the problem still exists. Dr. Portney, how do you define the importance of this problem and its effects?

PORTNEY: Let me try to indicate some of the policy responses to the ozone-depletion threat and suggest how it's regarded both in the United States and in the rest of the world.

The United States did ban all aerosol uses of chlorofluorocarbons—as you have indicated, uses in spray cans of deodorants, hair sprays, and the like—because of their potential ozone-depleting nature. One of the discouraging things about the United States' having taken that step is that chlorofluorocarbons released anywhere in the world have the same effect; it all goes into one big mixing layer in the stratosphere. So that if every country in the world but one cut out chlorofluorocarbons, and one country continued to pump them out, everybody would still suffer from the same problem. The point is that when the United States banned all aerosol use of chlorofluorocarbons, I believe only two or three other countries followed suit, and that's still true to this day.

Now the United States finds itself in the position of considering not bans on non-aerosol uses, but a limit on chlorofluorocarbon production. One of the plans that the Environmental Protection Agency is considering is the limitation of all CFC production (CFCs being chlorofluorocarbons) to either 1979 or 1980 levels. Again, however, while this would reduce the U.S. contribution to CFC production each year, and we are a major contributor, I do not believe we represent even as much as 30 percent of worldwide production. One of the discouraging things is that, if we take this step by ourselves and impose additional costs on this country by denying the use of chlorofluorocarbons in flexible foams, in rigid polyurethane foams, in coolants in refrigerators, and other uses, it will not have the impact that it would have if other countries in the world joined us and took similar steps. The Carter administration did try to initiate cooperative worldwide efforts on chlorofluoride control, but it remains to be seen whether the United States will pursue its own effort, and if we do, how successful we will be in enlisting the cooperation of the other CFC producers in the world.

ELLIS: Dr. Firor, I realize that ozone depletion is a separate problem from the increase in carbon dioxide in the atmosphere, but does the type of damage done to the atmosphere by ozone depletion link up and make worse the total damage to the atmosphere caused by these two problems?

FIROR: The problems link up in many ways. Incidentally, I'm calling them fluorocarbons, and Paul's calling them chlorofluorocarbons, but we are talking about the same subject.

It turns out that both carbon dioxide and fluorocarbons are exceedingly powerful absorbers of infrared radiation. Indeed, this absorption is what makes carbon dioxide troublesome in heating up the environment. Fluorocarbons also will heat up the environment, and because they are so much more powerful per molecule, it takes a lot fewer of them to do the job, so that some projections show fluorocarbons, by the middle of the next century, being perhaps half as important as carbon dioxide, and therefore pushing climate change more rapidly.

This warming effect has nothing to do with ozone, but the two problems link up, from a policy point of view, in that they are global, maybe countries contribute to them, there is no international mechanism for agreeing to do anything about them (no standing mechanism—we will have to create one) and there are scientific uncertainties about the timing and amount and size of the changes that will occur and their regional distribution. That's an important issue; none of these effects will be evenly spread over the earth.

Regional conflict threatens cooperation

PORTNEY: Let me elaborate a bit on John's last point. One of the really vexing difficulties of climate warming caused by carbon dioxide is that, as John has identified, it will have unequal regional effects. While the climate changes in one country may be negative—perhaps desertification or shortened growing seasons—other countries in northern climes, for instance, Canada and the Soviet Union, countries that now have shorter growing seasons and more difficult winters may find that some global warming, from carbon dioxide or anything else, may benefit them. Of course, that makes it a lot more difficult to take the necessary and, in some cases, very difficult steps, to prevent carbon dioxide buildup by imposing taxes on fossil fuels, or some kind of limit on the combustion of fossil fuels. Some countries can ask quite legitimately, Why should we penalize ourselves and cut down on our use of fossil fuels to prevent something that would be good for us in the first place?

So it's not just a matter of trying to secure international cooperation in the case where everybody is made a little worse off, but it may be in no one country's interest to penalize itself. That is difficult enough, but this is a case where some are going to be made better off, others are going o be made worse off, and there is even less incentive for international cooperation in this kind of instance.

Acid rain

ELLIS: Isn't this question of international cooperation and divergent interests, Dr. Firor, equally evident in the emerging problem of acid rain? I think of the fact that Canada complains that its lakelife is being killed by acid rain which emanates from the United States, that the Swedes say the same thing about Western Europe, and so on. As we look at this problem of acid rain, are we talking about something entirely different in a policy sense than the carbon dioxide and ozone depletion problem?

FIROR: I think it's different in that it is not quite global. The other two are distinctly and absolutely global, and we have to think of them as global problems because the substances are mixed clear around the earth. Acid rain, which results from sulfates and nitrates in the atmosphere, may move 100 miles or 1,000 miles, but it's not a global problem in the same sense.

We and the Canadians are going to have to get together. We both produce lots of sulfates and nitrates. The winds blow sometimes one way, and sometimes the other, so that at times we are producing their acid rain, and they are producing our acid rain a week later. So we need to get together and talk about it.

ELLIS: What types of manufacturing or other processing produce acid rain?

FIROR: That is a technical question, and it's a difficult one. We know that basic substances ending up as acids are sulfur oxides and nitrogen oxides. Sulfur oxides come largely from coal burning in factories and electric power-generation plants, with a little bit from oil burning. The nitrogen oxides come from a broader range of activities, including automobiles and other mobile sources. These substances in the atmosphere can oxidize to the next state of oxidation and form nitrates and sulfates, which are acidic, and which then dissolve in water and fall as rain or other precipitation.

Self-defeating policies?

ELLIS: It seems to me that, in the struggle of the United States and other industrial countries to reduce their dependence on OPEC oil, we are adopting policies which run counter to the risk that you gentlemen are pointing out. For example, at the 1980 Venice Economic Summit, I remember very well how each of the participants said, "We must all produce and use much more coal." Indeed, the United States committed itself to producing a great deal more coal and exporting it. If what you are saying is correct, not only about the problem of acid rain, but also about the increase of carbon dioxide, this is, in the very long run at least, a kind of self-defeating policy.

PORTNEY: As a practical matter that may be correct. I should point out, however, that if we were willing to commit large amounts of resources to removal of sulfur dioxide and nitrogen oxides from the flue gases of electric power plants and other kinds of coal-fired boilers, then we could, in fact, burn more coal and not necessarily exacerbate the acid rain problem. It does mean, however, that at a time when economic problems have become particularly vexing, we would be increasing our commitment to stack scrubbing or fluidized-bed combustion, new and expensive technological means of removing pollutants before they get into the atmosphere.

And I believe it is also the case with respect to carbon dioxide that there are at least imaginable technological solutions to the problem. We could continue to burn fossil fuels, for instance, and, in what may sound like a Jules Vernian solution, pump carbon dioxide into the oceans before it comes out of the stack. Now whether that would be an ultimate solution to the problem, I don't know, but it almost certainly would be extraordinarily expensive. I should stress that I am not advocating a technological solution in general, let alone pushing a particular technology. My only point is that it's not necessarily the case that more use of domestic coal inevitably would not and forever exacerbate carbon dioxide buildup or the acid rain problem. It would mean we would be spending more, and that is something that we have to think seriously about as well.

FIROR: Paul's right in saying that there are varying degrees of technological solutions to these problems. Acid rain may e the easiest one, for the reasons he mentions, and getting rid of the sulfur from coal at least sounds feasible. And getting rid of the nitrogen oxides from automobile exhaust is something that's schedule to occur if we don't back away from our clean air standards.

ELLIS: If a lake or other body of water has "died" because of acid rain—that is, it now supports neither plant nor fish life—can it be brought back?

FIROR: Only with difficulty. You can dump a lot of, say, lime into the lake and neutralize the acid, but it would take quite a while for the lake's living systems to recur.

Part of the trouble with acid in the lakes is that it mobilizes substances that are usually not dynamic. Rocks at the bottom of the lake have heavy metals in them which usually stay in the rock. Acid dissolves them and produces then, in solution, some cadmium, arsenic, mercury, or other toxic substances that the lake ordinarily would not have.

SO a lake can be pretty thoroughly poisoned by the secondary effects of acid rain, and cleaning it up is a big task. The effect is reversible in the sense that, if by magic we quit putting all those acid-producing substances in the atmosphere, the atmosphere would cleanse itself in a matter of weeks. These things just do not stay there that long. Then there would be a very long recovery period of the ecosystem, which works much more slowly. Some lakes probably would take a century to come back to their preindustrial state.

International leadership needed

ELLIS: Clearly, from all you have said, if we simply consider the United States in isolation, there are myriad problems—economic and political, scientific and technical. But it is not, of course—the United States in isolation, as you both have brought up.

PORTNEY: That's an excellent point, one that brings up a recent event that is troubling in its portents for international cooperation in this area. We ave identified that certainly acid rain has international ramifications, as do chlorofluorocarbon emissions and the concomitant depletion of ozone, as well as carbon dioxide buildup in the atmosphere resulting from fossil fuel combustion. It's clear that we need more international cooperation to deal with these international problems, and I wonder what role the United States is prepared to play. I bring that up because the United States recently reversed its position on the Law of the Sea Treaty, which had been negotiated over a seven-year period, and had the near-unanimous consent of the nations involve; at the last minute the United States decided not to sign the treaty. I think that raises the question of whether other nations are going to want to follow the United States in other kinds of international environmental; cooperative ventures, if they fear that the United States may pull out.

ELLIS: Does that lead to the conclusion that the scientific community has to find a way to impress upon the Reagan administration the enormity of the dangers involved, and the probability, if not the certainty, of the risks?

FIROR: We have our work cut out for us, because, at least in their public statements, the people in the administration have downgraded these problems. And, to be fair, people speaking for the environment side sometimes have exaggerated certain problems and have strained their credibility.

But certainly we have to give it a try. The scientific world must do its homework very well; it must be skeptical of its own work; it must make sue that its predictions are credible, and that they are soundly based. And then there is the selling job, and that will be very difficult.