We are living in an increasingly shrinking world. Instant communication and the internet have seemingly dissolved time, space and cultural boundaries. The international movement of peoples has reached levels previously unheard of. Globalization has become a catchphrase for our times.

The atmospheric sciences have partly led and partly responded to this process. The extent of continental, hemispheric – and even global – transport of air pollution has become an issue of increasing scientific and policy concern; and nothing emphasises the fragile unity of the planet more graphically than the increasing evidence of climate change – and the portentous implications that emerge as we contemplate the possible consequences of the interaction of air pollution and climate change.

Yet appearances can be deceptive, and are only part of the story. Even for scientists, the ‘Big Picture’ is never easy, and, for the most part, the pressures of professional life mean that we must concentrate on the particular and limit ourselves to our own field. We are able only from time to time to look outside our own boxes, and this task paradoxically becomes more difficult as the totality of knowledge in our separate specialties increases.

For the ordinary citizen, with no specialist training in the atmospheric sciences, there is a similar problem. The unity of the atmosphere, and of the atmospheric sciences, is less easy to grasp than the variety of seemingly separate problems, such as climate change, ozone depletion, urban pollution, and industrial and vehicle emissions, which at different times rightly command separate and urgent attention.

Atmospheric pollution affects us all. It affects our health and our environment. It is our activities and actions, however, which are resulting in the continual pollution of the atmosphere. For example, road transport has emerged as one of the most important sources of air pollution, particularly in urbanised areas such as mega-cities. Although emissions from other sources, such as industrial and domestic have reduced in developed countries, they still make a significant contribution to the overall pollution burden of the atmosphere in many less developed regions.

It is not only the directly emitted pollutants that can be hazardous to our health and the environment. Pollutants can also react with each other in the presence of sunlight to produce harmful photochemical smog, which affects many cities around the world. Once released into the atmosphere, pollutants can be dispersed into buildings and along streets as well as affect whole city areas. As a result of meteorological processes air pollution can also be transported across continents and, depending on the particular chemical species, remain in the global atmosphere for long periods of time. Pollution emitted locally by cars, industrial chimneys or forest fires, therefore, can have an impact on regional and global scales. On the other hand, pollutants such as aerosols and carbon dioxide, which influence the global radiation balance of the atmosphere, can lead to changes in the natural climate of the world with direct impacts on urban and local scales.

This introduction brings together the separate, but interlinked, themes of the chapters. Some of the key concepts of atmospheric pollution are explained to help those readers who are not familiar with the subject area but have a science background. This section also explains the overall structure of the Atlas and the approach adopted by the contributors. A list of useful reading material is provided at the end of the Atlas for those who are interested in an in-depth treatment of atmospheric science and pollution.

The Earth's Atmosphere

Radiation Balance of the Atmosphere

The overall atmospheric dynamics and the climate system are driven by the energy from the sun. Much of the incoming solar radiation is transmitted through the atmosphere and absorbed by the earth's surface (see Figure I.1). Some of this short-wave radiation is reflected by ground surfaces such as snow and deserts, and by clouds. About 30 per cent of the solar radiation incident on the earth is reflected back into space by clouds, the atmosphere and the earth's surface (Kiehl and Trenberth 1997). Approximately 20 per cent of the incident radiation is absorbed by the atmosphere, and the remaining proportion (about 50 per cent) warms the earth's surface (land and the oceans).

The proportion of incoming radiation that is reflected back by a surface depends on its reflectivity, and is termed ‘albedo’. For example, albedo of fresh snow is typically 0.8 and that of the earth and the atmosphere, 0.3.

The scientific and technological developments of the twentieth century occurred within economic or social systems such as capitalism and communism. Of the two, capitalism generated by far the most such developments. As the economist Joseph Schumpeter noted, in its search for new products, new consumers, and new markets, capitalism constantly revolutionized “the economic structure from within, incessantly destroying the old one, incessantly creating a new one.” He even wrote that “this process of Creative Destruction is the essential fact about capitalism.” The system itself can be defined as an economic one in which means of production such as land, labor, and machinery are privately owned by individuals and businesses that produce and exchange goods and services primarily to earn a profit—in contrast, under communism the government usually owned the means of production. By 1900, countries with capitalist economies dominated the globe. Among them the United States, Germany, Great Britain, and France were the leading powers, and to a lesser extent Austria- Hungary and Russia, in both of which capitalism was at a less advanced stage of development. Although socialism/communism was advocated by the German-born Karl Marx (1818–83), no communist party was able to come to power until the communist revolution of 1917 in Russia.

Although Marx recognized the tremendous productive capability of capitalism, he also believed that it was flawed by “growing inequalities, bitter class conflict, worsening cycles of economic expansion and recession, [and] competitive and individualistic values.”

‘Prediction is very difficult, especially if it's about the future’ (Niels Bohr, Nobel laureate in Physics). For instance, forecasters in Victorian London foresaw their city knee-deep in horse manure, one of the most pertinent urban environmental problems in cities at that time. A hundred years later, this prediction has not materialized and the situation has changed drastically. While traffic itself is still considered a major cause of urban air pollution, the contribution from horses has entirely disappeared and motorized vehicles are now the major source of deteriorated air quality in most modern cities.

Given the failure of simple extrapolations of present trends into the future, what can we say about air pollution in the coming decades?

To begin with, we know that population will further increase in urban areas, and we know that all societies aim to further strengthen their economic wealth. For a long time, air pollution from anthropogenic (non-natural) activities has been considered an unavoidable concomitant of economic development. Over long historic periods, we have seen air pollution levels increasing together with economic growth. Countermeasures to control air pollution have often been considered too costly to put into effect without compromising economic wealth.

Following this logic, the envisaged continued growth in global population, together with the universal target of improving prosperity, would lead to drastically worsened air quality around the globe, especially in many developing countries.

Early air pollution control efforts were prompted by urban episodes due to local emissions, such as the 1952 London smog associated with sulphur from burning coal (see Chapter 1). Although local areas typically experience the highest levels of health- and ecosystemdamaging air pollution, many species remain in the atmosphere for days, months, or even years. The longer a pollutant stays in the atmosphere, the farther from its original source it travels. For example, it takes about five days for a pollutant to cross the Pacific Ocean, but over a year for pollution to cross from the Northern Hemisphere mid-latitudes to the Southern Hemisphere. An example of such a pollutant plume as seen by satellite is shown in Figure 3.1.

Regional Air Pollution Transport

Although early scientific and regulatory efforts focused on local emissions and local effects, since the late 1970s, the geographic scale on which pollutant transport is studied and regulated has expanded. In Europe, the UNECE Convention on Long-Range Transbounday Air Pollution (LTRAP, www.unece. org/env/lrtap) came into force in 1983, driven by a concern about acid rain in Europe, and it has since expanded to address nitrogen deposition, ozone, heavy metals, particulate matter, and persistent organic pollutants (POPs). Scientific support for the Convention is provided through the Cooperative Programme for Monitoring and Evaluation of the Long-Range Transmission of Air Pollutants in Europe (EMEP), which assesses air pollution impacts on Europe.

Postmodernism, Culture, and Science

The Columbia Encyclopedia, 6th ed. (2000), defines postmodernism as follows:

Postmodernists rejected any absolute or objective truths, whether scientific, political, religious, or cultural, thus tending to an extreme relativism. Instead, they stressed conflicting viewpoints and the blurring of distinctions between images and reality. By the late 1980s this viewpoint was even evident in the Soviet Union under the more permissive Mikhail Gorbachev. Victor Erofeyev, a Russian writer, described the new movement in literature, “The new Russian literature has called absolutely everything into question: love, children, faith, the Church, culture, beauty, nobility of character, motherhood, and even the wisdom of the common people.”

Postmodernism spread not only to different parts of the globe, but to different fields such as literary criticism, the social sciences, and humanities. One of its most significant manifestations was deconstructionism.

Many of the developments discussed in this book—violence, science and technology, capitalism and communism, imperialism, freedom, the environment—were intertwined with culture. In the broadest sense and in the way many anthropologists use the term, culture embraces the whole way of life of a group, including their physical and mental activities: thus, Chinese, French, or U.S. culture, or even more broadly Asian, Western, or African culture. Related to this definition are terms such as “youth culture” or “popular culture,” both indicating an aspect or subculture of a larger culture. Subcultures can sometimes seem more significant than a larger culture. Being raised in a Jewish or Catholic subculture in the early twentieth century, for example, might have had a greater impact on a young person than being brought up in an English or U.S. culture.

The term culture has also often been used as a collective term for the arts, humanities, and higher knowledge generally. This is a more elitist definition, sometimes referred to as “high culture,” and is related to what is meant by referring to someone as “a very cultured person.” Usually the context in which the word is used makes clear whether the broader or more restrictive use is intended.

Cultural Criticism of Capitalist Society in the Early Twentieth Century

In England during the nineteenth century, the poet Matthew Arnold and others had thought of high culture as an alternative and corrective to the values and manners that the Industrial Revolution and laissezfaire capitalism had introduced into English society.

The increasing body of observations has shown that we are faced with a warming world and other changes in the climate system brought about by increasing anthropogenic (human induced) pollution of our atmosphere. The global average surface temperature has increased over the twentieth century by about 0.6 °C (IPCC 2001a). The Fourth Assessment Report (AR4) of the International Panel on Climate Change (IPCC) has re-estimated the global average surface temperature in light of new research and derived a slightly higher warming magnitude due to inclusion of several particularly warm years in this century (2003, 2004, 2005 and 2006) (IPCC 2007; Meehl et al. 2007). The changes in climate, with global warming as their major characteristic feature, are known to occur as a result of internal variability within the climate system and external factors (both natural and anthropogenic). Based on the conclusions derived by IPCC in their Third Assessment Report or TAR in short form (IPCC 2001b) and now in AR4 (IPCC 2007), there is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities. As a result of these anthropogenic activities, concentrations of atmospheric greenhouse gases and their radiative forcing have continued to increasesince 1750 (the pre-industrial era), thus leading to global warming and significant environmental consequences. Now the emissions of greenhouse gases and aerosols are of major environmental concern throughout the world as an issue of global air pollution.

In the 1860s the Russian novelist Leo Tolstoy accused historians of muddled thinking when they wrote of progress. Emphasizing the dazzling array of new technologies—in print, transportation, communication (railroads, steam engines, telegraphs, and the like)—historians seemed to assume that such developments necessarily contributed to improvements in the overall welfare of individuals and nations. But Tolstoy was convinced that “progress on one side is always paid back by retrogression on the other side of human life.” For him the growth of cities and newspapers, gas-lighting, railways, and sewing machines, all were either regressive developments or not worth the cost of destroying forests and people's sense of simplicity and moderation. Whether Tolstoy was right or wrong about the effects of such developments is less important than the questions his criticism prompts. What is progress? How is it to be measured? Tolstoy himself equated it with an overall improvement of well-being, which is perhaps as good a definition as any. Thus, the task at hand is to summarize the changing nature of global well-being over the course of the twentieth century, as well as changing perceptions about it.

A key figure in developing the nineteenth-century view of progress, criticized by Tolstoy, was the eighteenth century Scotch economist Adam Smith. He believed that economic progress depended upon the division of labor, free trade, and people pursuing their own economic self-interest.