Every one of us is sustained by various kinds of natural resources – such as food, materials, and energy that are harvested or otherwise extracted from the environment. Our need for those resources is absolute – we cannot survive without them. Moreover, the same is true of all other species – every organism is a component of an ecosystem that provides the means of subsistence.
Collectively, the needs and activities of people comprise a human economy. That economy operates at various scales, ranging from an individual person, to a family, to communities such as towns and cities, nation-states (such as Canada), and ultimately the global human enterprise. While an enormous (and rapidly growing) number of people are supported by the global economy, a lot of environmental damage is also being caused. The most important of the damages are the depletion of vital natural resources, various kinds of pollution (including climate change), and widespread destruction of natural habitats to the extent that the survival of many of the natural ecosystems and species of Earth are at grave risk.
These issues are of vital importance to all people, and to all life on the planet. Their subject matter provides the context for a wide-ranging field of knowledge called environmental studies, an extremely broad field of knowledge that examines the scientific, social, and cultural aspects of environmental issues. As such, the subject matter of environmental studies engages all forms of understanding that are relevant to identifying, understanding, and resolving environmental problems. Within that context, environmental science examines the science-related implications of environmental issues (this is explained in more detail in the following section). The subject matter of environmental science is the focus of this book.
Issues related to environmental problems are extremely diverse and they interact in myriad ways. Despite this complexity, environmental issues can be studied by aggregating them into three broad categories:
1. the causes and consequences of the rapidly increasing human population
2. the use and depletion of natural resources
3. damage caused by pollution and disturbances, including the endangerment of biodiversity
These are extremely big issues – their sustainable resolution poses great challenges to people and their economy at all scales. Nevertheless, it is important to understand that the study of environmental issues should not be regarded as being a gloomy task of understanding awful problems – rather, the major goal is to identify problems and find practical ways to repair them and prevent others from occurring. These are worthwhile and necessary actions that represent real progress towards an ecologically sustainable economy. As such, people who understand and work towards the resolution of environmental problems can achieve high levels of satisfaction with their contribution, which is something that helps to make life worth living.
Image 1.1. Planet Earth. Earth is the third closest planet to the Sun, and it is the only place in the universe that is definitely known to sustain life and ecosystems. Other than sunlight, the natural resources needed to sustain the human economy are restricted to the limited amounts that can be extracted on Earth. This image of the Western Hemisphere was taken from a distance of 35-thousand km from the surface of Earth.
Specialists examining these and other questions related to environmental issues may come from many specific areas of study, each of which is referred to as a discipline. However, the various ways of understanding each issue may be integrated into comprehensive studies of the subject matter – this is why environmental studies is referred to as interdisciplinary field. For environmental science, the most relevant of the disciplinary subjects are atmospheric science, biology, chemistry, computer science, ecology, geography, geology, mathematics, medical science, oceanography, physics, and statistics. This is illustrated in Figure 1.1, which suggests that all fields of scientific knowledge are relevant to understanding the causes, consequences, and resolution of environmental problems.
Figure 1.1. Environmental science has an interdisciplinary character. All scientific disciplines are relevant to the identification and resolution of environmental issues. However, the work requires an interdisciplinary approach that engages many disciplines in a coordinated manner. This integration is suggested by the overlaps among the disciplinary fields.
This lesson deals with the key subject areas of environmental science. To some degree, however, certain non-science topics are also examined because they are vital to understanding and resolving environmental issues. These non-science fields include ethics, philosophy, and economics.
Of all of the academic disciplines, ecology is the most relevant to environmental science, and in fact the terms are often confused. Ecology may be defined simply as the study of the relationships of organisms with their environment. Ecology is itself a highly interdisciplinary field of study – it mostly involves biology, but knowledge of chemistry, computer science, mathematics, physics, geology, and other fields is also important. Geography is another interdisciplinary field that is central to environmental science. Geography can be simply defined as the study of natural features of Earth’s surface, including climate, soil, topography, and vegetation, as well as intersections with the human economy. Obviously, ecology and geography are closely related fields.
Increasing numbers of scientists are studying human (or anthropogenic) influences on ecosystems, occurring as a result of pollution, disturbances, and other stressors. Examples of the major subject areas are:
1. The extraction, processing, and use of non-renewable resources, such as fossil fuels and metals, in ways that do not cause unacceptable environmental damage, while also moderating their depletion to some possible degree (for example, by re-cycling certain materials)
2. The harvesting and management of biological resources, such as those in agriculture, fisheries, and forestry, in ways that allow them to fully regenerate so their stocks can be sustained into the future
3. The growth of renewable sources of energy, such as the various forms of solar energy (including biomass fuels, hydroelectricity, photovoltaics, and wind), as a way of replacing non-renewable fossil fuels and thereby making the energy economy more sustainable
4. The prevention and repair of ecological damages, such as those related to endangered biodiversity, degraded land or water, and the management of greenhouse gases
An environmental scientist is a generalist who uses science-related knowledge relevant to environmental quality, such as air or water chemistry, climate modelling, or the ecological effects of pollution. Another group of people, known as environmentalists, is also involved with these sorts of issues, especially in the sense of advocacy. This involves taking a strong public stance on a particular environmental issue, in terms of the need to address the problem. However, any person can be called an environmentalist if they care about the quality of the environment and work towards changes that would help to resolve the issue.
Environmentalists may work as individuals, and they often pursue their advocacy through non-governmental organizations .
NOTE: Take Quiz 1.1 before proceeding to next lesson.