Greenhouse Effect (The Concise Encyclopedia of Economics, 2002)

by Thomas C. Schelling

 

Thomas C. Schelling is a professor of Economics at the University of Maryland School of Public Affairs in College
Park. For most of his professional life he was an economics professor at Harvard University. In 1991 he was

president of the American Economic Association. He is an elected member of the National Academy of Sciences.    In 2005 Thomas C. Schelling won the Nobel Memorial Prize in Economic Sciences.

 

The excerpt below is shorter than the original article. A full version of “Greenhouse Effect” is available at
<http://www.econlib.org/library/Enc1/GreenhouseEffect.html>.

 

Students: Read actively. Even if your instructor does not formally assign the ten content questions or dictionary
work for the highlighted vocabulary, stop at the end of each section and ask yourself the questions.  Without
reading closely and actively, you will struggle to complete the required reading response (300 words).

 

 

1. Introduction

The “greenhouse effect” is a complicated process by which the earth is becoming progressively warmer. The earth is bathed in sunlight, some of it reflected back into space and some absorbed. If the absorption is not matched by radiation back into space, the earth will get warmer until the intensity of that radiation matches the incoming sunlight. Some atmospheric gases absorb outward infrared radiation, warming the atmosphere. Carbon dioxide is one of these gases; so are methane, nitrous oxide, and the chlorofluorocarbons (CFCs). The concentrations of these gases are increasing, with the result that the earth is absorbing more sunlight and getting warmer.

This greenhouse phenomenon is truly the result of a “global common” (see The Tragedy of the Commons). Because no one owns the atmosphere, no one has a sufficient incentive to take account of the change to the atmosphere caused by his or her emission of carbon. Also, carbon emitted has the same effect no matter where on earth it happens.

 

Question 1: Explain the following terms:

— greenhouse effect

— global common

— developed countries

— developing countries 

 

Question 2: What two topics does the introduction focus on?

 

2. How Serious Is It?

The expected change in global average temperature for a doubling of CO₂ is 1.5 to 4.5 degrees centigrade. But translating a change in temperature into a change in climates is full of uncertainties. Meteorologists predict greater temperature change in the polar regions than near the equator. This change could cause changes in circulation of air and water. The results may be warmer temperatures in some places and colder in others, wetter climates in some places and drier in others.

Temperature is useful as an index of climate change. A band of about one degree covers variations in average temperatures since the last ice age. This means that climates will change more in the next one hundred years than in the last ten thousand. But to put this in perspective, remember that people have been migrating great distances for thousands of years, experiencing changes in climate greater than any being forecast.

The models of global warming project only gradual changes. Climates will “migrate” slowly. The climate of Kansas may become like Oklahoma’s, but not like that of Oregon or Massachusetts. But a caveat is in order: the models probably cannot project discontinuities because nothing goes into them that will produce drastic change. There may be phenomena that could produce drastic changes, but they are not known with enough confidence to introduce into the models.

Carbon dioxide has increased about 25 percent since the onset of the industrial revolution. The global average temperature rose almost half a degree during the first forty years of this century, was level for the next forty, and rose during the eighties. Yet whether or not we are witnessing the greenhouse effect is unknown because other decades-long influences such as changes in solar intensity and in the atmosphere’s particulate matter can obscure any smooth greenhouse trend. In other words, the increase in carbon dioxide will, by itself, cause the greenhouse effect, but other changes in the universe may offset it.

Even if we had confident estimates of climate change for different regions of the world, there would be uncertainties about the kind of world we will have fifty or a hundred years from now. Suppose the kind of climate change expected between now and, say, 2080 had already taken place, since 1900. Ask a seventy-five-year-old farm couple living on the same farm where they were born: would the change in the climate be among the most dramatic changes in either their farming or their lifestyle? The answer most likely would be no. Changes from horses to tractors and from kerosene to electricity would be much more important.

Climate change would have made a vastly greater difference to the way people lived and earned their living in 1900 than today. Today, little of our gross domestic product is produced outdoors, and therefore, little is susceptible to climate. Agriculture and forestry are less than 3 percent of total output, and little else is much affected. Even if agricultural productivity declined by a third over the next half-century, the per capitaGNP we might have achieved by 2050 we would still achieve in 2051. Considering that agricultural productivity in most parts of the world continues to improve (and that many crops may benefit directly from enhanced photosynthesis due to increased carbon dioxide), it is not at all certain that the net impact on agriculture will be negative or much noticed in the developed world.

 

Question 3: According to Paragraph 1 of this section, why is it difficult to translate a change in temperature to a change in climate?

 

Question 4: What does Schelling mean in Paragraph 4 of this section when hewrites, “whether or not we are witnessing the greenhouse effect is unknown”?

 

Question 5: Why does Schelling state in Paragraph 6 of this section that climate change would have made a greater difference to the way people lived in the past than today?

 

 

3. Its Effects on Developing Countries

Climate changes would have greater impact in underdeveloped countries. Agriculture provides the livelihoods of 30 percent or more of the population in much of the developing world. While there is no strong presumption that the climates prevailing in different regions fifty or a hundred years from now will be less conducive to food production, those people are vulnerable in a way that Americans and west Europeans are not. Nor can the impact on their health be dismissed. Parasitic and other vectorborne diseases affecting hundreds of millions of people are sensitive to climate.

Yet the trend in developing countries is to be less dependent on agriculture. If per capita income in such countries grows in the next forty years as rapidly as it has in the forty just past, vulnerability to climate change should diminish. This is pertinent to whether developing countries should make sacrifices to minimize the emission of gases that may change climate to their disadvantage. Their best defense against climate change will be their own continued development.

Population is an important factor. Carbon emissions in developing countries rise with population. For instance, if China holds population growth to near zero for the next couple of generations, it may do as much for the earth’s atmosphere as would a heroic anticarbon program coupled with 2 percent annual population growth. Furthermore, the most likely adverse impact of climate change would be on food production, and in the poorest parts of the world the adequacy of food depends on the number of mouths.

 

Question 6: According to this section, what effectscould climate change have on developing countries?

 

Question 7: What does Schelling suggest might help developing countries?

 

 

4. Why Should Developed Countries Do Anything?

 

Why might developed countries care enough about climate to do anything about it? The answer depends on how much people in developed countries care about people in developing countries and on how expensive it is to do something worthwhile. Abatement programs in a number of econometric models suggest that doing something worthwhile would cost about 2 percent of GNP in perpetuity. Two percent of the U.S. GNP is over $100 billion a year, and that is an annual cost that would continue forever.

One argument for doing something is that the developing countries are vulnerable, and we care about their well-being. But if the developed countries were prepared to invest, say, $200 billion a year in greenhouse gas abatement, explicitly for the benefit of developing countries fifty years or more from now, the developing countries would probably clamor, understandably, to receive the resources immediately in support of their continued development.

A second argument is that our natural environment may be severely damaged. This is the crux of the political debate over the greenhouse effect, but it is an issue that no one really understands. It is difficult to know how to value what is at risk, and difficult even to know just what is at risk. The benefits of slowing climate change by some particular amount are even more uncertain.

A third argument is that the conclusion I reported earlier—that climates will change slowly and not much—may be wrong. The models do not produce surprises. The possibility has to be considered that some atmospheric or oceanic circulatory systems may flip to alternative equilibria, producing regional changes that are sudden and extreme. A currently discussed possibility is in the way oceans behave. If the gulf stream flipped into a new pattern, the climatic consequences might be sudden and severe. (Paradoxically, global warming might severely cool western Europe.)

Is 2 percent of GNP forever, to postpone the doubling of carbon in the atmosphere, a big number or a small one? That depends on what the comparison is. A better question—assuming we were prepared to spend 2 percent of GNP to reduce the damage from climate change—is whether we might find better uses for the money.

I mentioned one such use—directly investing to improve the economies of the poorer countries. Another would be direct investment in preserving species or ecosystems or wilderness areas, if the alternative is to invest trillions in the reduction of carbon emissions.

 

Question 8: In Paragraph 1 of this section, Schelling talks about two factors that can determine whether or not developed countries will do anything about climate change. What are these two factors?

 

Question 9: According to Paragraph 4 in this section, “global warming might severely cool western Europe.”  Explain how this might happen.

 

Question 10: In the last paragraph of this section Schelling suggests two waysofreducing the effects of climate change in developing countries. What are they?

 

 

 

20D Reading Response

 

Write a three-paragraph reading response (about 300 words)to the topic assigned by your instructor.

 

 

TOPIC 1

In Paragraphs 2, 3 and 4 of Section 4, Schelling talks about three arguments people make for helping developing countries. What are these arguments and what makes Schelling agree or disagree with them? Write three paragraphs, each one devoted to one argument and Schelling’s stance on it.

 

TOPIC 2

Reread Section 2, entitled “How Serious is it?” Name three of the arguments Schelling makes in Section 2 to convince his readers that climate change will not affect them very much. For each argument, explain what makes it convincing or unconvincing to you. Write three paragraphs, each one devoted to one of his arguments and your reaction to it.

 

TOPIC 3

Look closely at the last paragraph of Section 2 and explain who Schelling’s target audience is when he uses the words “people,” “our” and “we.” Then look at the second paragraph of Section 4 and examine how the words “we” and “their” are used.  What images are associated with “we” and “they,” and how convincing do you find these images in a discussion of the problem of global warming? Write one paragraph about the images related to “we, ” one paragraph about the images related to “they,” and one paragraph in which you comment on how convincing they both are.

 

 

 vClick here to have a similar paper done for you by one of our writers within the set deadline at a discounted…

 

 

 

 Click here to have a similar paper done for you by one of our writers within the set deadline at a discounted…