Introduction Introduction Doing Science Science & Society Our Environmental Heritage The Science of Global Change Summary The materials of science are the material of life itself. Science is part of the reality of living; it is the what, the how, and the why of everything in our experience. It is impossible to understand man without understanding his environment and the forces that have molded him physically and mentally. The aim of science is to discover and illuminate truth. Rachel Carson Whatever knowledge is attainable, must be obtained by scientific methods, and what science cannot discover, mankind cannot know. Bertrand Russell Introduction • Earth science, geology and environmental geology involve the study of the Earth and the processes that shape its surface but have different emphases. • The Earth System is composed of four principal components: atmosphere, hydrosphere, biosphere, and the solid Earth. • The science of Earth becomes relevant to society when we examine the interaction between human beings and the planet we share. The Good Earth represents an attempt to introduce students to Earth Science with an emphasis on our interaction with our environment. Consequently, this text includes components from two common undergraduate courses, Earth Science and Environmental Geology. These courses have more elements in common than they have differences. • Geology is the study of the Earth. That includes how the planet was formed, what it is made from, and how it has changed over time. Geologists study the processes that occur on Earth's surface and others taking place within the planet's interior. • Environmental geology views geology through the prism of the human experience. Environmental geology traditionally places less emphasis on the origin and history of the planet and focuses on geologic hazards, the consequences of resource development, and the alteration of the natural environment. • Earth science is broadly defined as the study of the interactions of the four components of the Earth system - the atmosphere, hydrosphere, biosphere and solid Earth. Consequently, it overlaps with other disciplines such as meteorology (weather systems, climate), oceanography (ocean processes), biology (ecosystems), and geology. However, increasingly, the boundaries between Earth science and environmental geology are blurring as scientists define environmental problems at a global scale that require us to understand the interaction between all elements of the Earth system. Consequently, this text looks at the interaction between society and the Earth system as a whole. For the study of Earth to be relevant to our lives it must involve an examination of how people are affected by the processes that shape the Earth 2 and how we utilize the planet's resources (minerals, energy, water, air, soil). The Good Earth describes the interaction of rock on and below the surface of the solid Earth with waters of Earth's hydrosphere (streams, lakes, oceans), and the processes of Earth's atmosphere that give us our daily weather and long- term climates. These components fit together to form the earth system, an environment that supports life on and near Earth's surface (biosphere). None of these components can exist without the others. Without the oceans there would be little source of water to evaporate to supply the atmosphere with precipitation. Without the atmosphere bringing precipitation, rocks could not break down to form soil. Without soils Figure 1. The principal vegetation would not flourish to absorb the toxic carbon components of the Earth dioxide that we exhale and produce the oxygen we inhale (see system include the solid Fig. 1). Earth (rocks, internal and surficial earth processes), This chapter is divided into six principal sections, including the hydrosphere (streams, this introduction. We begin with the basics, describing the oceans, ice caps), the scientific process itself. In the section titled Doing Science we atmosphere (weather, explain how scientists conduct investigations that allow them climate), and the to weave together data collected from experiments and biosphere (population, observations of the natural world. The application of the ecosystems, land use). Image courtesy of NASA's scientific approach is illustrated by discussions about the planetary photojournal. extinction of the dinosaurs and the investigation of a hypothesis of a potentially dangerous earthquake source in the Great Plains. We also examine cases where individuals attempted to circumvent the rigors of the scientific process to forward controversial ideas founded on poor science. Mankind has been unconsciously interacting with the environment since our human ancestors began to roam the earth. Our demands on the planet have been magnified as technology evolved and population increased. The principal elements of the environment (air, water, soil) have specific chemical and physical characteristics that can be readily measured. Scientists can determine the volume of dust in the air or the abundance of a chemical in a stream to determine if the air or water quality falls below community standards. The presence of specific pollutants in the environment can be readily detected and steps can be taken to protect the health of the community and of natural ecosystems. For example, the Toxic Release Inventory (TRI) required companies to notify their communities about the volume of toxic emissions. Following the release of the first figures in the late 1980s, 3 emissions declined precipitously as many companies learned it was both good business and good public relations to reduce emissions. Such social or cultural influences on decisions affecting the environment are more difficult to quantify than physical and chemical conditions. Consequently, they are more complex to Regulations that evaluate in decision making and are often the subject of measure physical or vigorous debate. Furthermore, the influence of these factors chemical environmental change with time as social perceptions change. For example, characteristics our view of the role of wilderness has evolved in the four Clean Air Act hundred years since the earliest European settlers arrived on Safe Drinking Water Act the North American continent. Wilderness was regarded with hostility by early colonists who considered the virgin forests to Examples of legislation be home to hostile natives and mythical beasts. However, as enacted for cultural population expanded and the number of wilderness areas concerns dwindled the remaining natural lands began to be considered Wilderness Act Endangered Species Act important cultural asset and were protected by legislation such as as the Wilderness Act (1964). The third section of the chapter, Science and Society, examines how our knowledge of the Earth allows us to protect people from hazardous earth processes, manage economic resources, and protect the Earth from activities that may endanger natural ecosystems. We discuss the principal roles of the Earth sciences in our lives, from the benefits of basic research to the implications of global change for the future of humanity. This section serves as an introduction to these themes that are present throughout The Good Earth. Links to specific chapters are included, think of the Science and Society section as a road map of the text. Americans’ interaction with the environment can be traced back to the continent's earliest inhabitants. However, it was the actions of European colonists that first resulted in widespread environmental degradation and led to early legislation to protect wildlife. An appreciation for the land blossomed in the nineteenth century, prompting the creation of forest reserves and the earliest national parks. This century has been marked by a growing concern for pollution of the environment at both regional and global scales. Two sections of the chapter divide our collective environmental heritage into two parts (Environment pre-1899, Environment post-1900) and examine the evolution of environmental thought in the U.S. 4 Finally, we finish the chapter by introducing the concept of global change, an idea that is currently generating research in a variety of disciplines including geology, ecology, chemistry, oceanography, and climatology. In this chapter we will describe the scale of the scientific enterprise behind investigating a substantial problem such as global change. It will become evident that such research requires the work of thousands of scientists throughout the globe. This research has implications for the long-term quality of life for humanity and is likely to require difficult social decisions within your lifetime. Future economic, cultural, and political choices in all the world's nations will depend on the rate and degree of global change. We will follow the theme of global change through many of the chapters of The Good Earth. Global change represents a consistent idea that we will use to link together the principal components of the Earth system to illustrate how tightly the atmosphere, hydrosphere, biosphere and solid Earth are linked together. Think about it . 1. Examine the photograph located below and identify the components of the Earth system represented in the image, and consider what information we would need to have about the natural environment to live in such a location. 2. Draw a concept map that illustrates examples of interactions between the four components of the Earth system. 5 Doing Science • Scientists use observations to form testable hypotheses. • Inaccurate