What is Environmental Science? Use the buttons at the bottom of the screen to play, pause, stop, and advance or rewind this session. Slide 2
Environmental science is the study of how humans interact with the environment Our environment consists of everything that surrounds us. Environmental science is an interdisciplinary science that incorporates aspects of chemistry, biology, earth science, physics, and even many of the social sciences. Due to the number and magnitude of the environmental problems that already exist, environmental science focuses primarily on the reactive approach of solving environmental problems. Slide 3
Although there are many individual environmental problems in our world today, for the most part they can all be categorized into one of three groups. The first major category of environmental problems is resource depletion. Resource depletion is the depletion of our Earth's natural resources. A natural resource is any natural substance that living things use. Some examples of natural resources are air, soil, minerals, plants, sunlight, animals, and fossil fuels. A resource is considered to be depleted when a large portion has been used up. When considering resource depletion we must look at both renewable resources, or resources that are continually being replaced, and nonrenewable resources, or resources that can’t be replaced. Although many people think of renewable resources as those that cannot be depleted, some of these can become depleted even though they are renewable. The second major category of environmental problems is pollution. Pollution occurs when harmful levels of chemicals or waste materials are introduced into the environment. The primary types of pollution are air pollution, water pollution, and soil pollution. The third major category of environmental problems is extinction. A species is said to be extinct when the last individual member of the species has died and the species is gone forever. The primary cause of species extinction in today's world is destruction of natural habitats. Although there is no way to know precisely how many species are becoming extinct each year many scientists estimate that the number could be well into the thousands. Slide 4
Many environmental problems are what we call global environmental problems. This means that an action in one part of the world has an effect on the environment in another part of the world.
This results from the fact that all living and nonliving things exist in a very close relationship with one another within the biosphere. The biosphere is a thin layer around the Earth in which all living organisms exist. The biosphere extends from the surface of the Earth to about 8 km above the surface and to about 8 km into the deepest part of the ocean. Slide 5
Increasing human populations and increasing demand on natural resources are the root of many environmental problems. It is important to consider, however, that people in different parts of the biosphere have very different immediate needs and concerns. The greatest observable differences occur between developed countries, which are highly industrialized countries whose citizens have high average incomes, and developing countries, which are less industrialized countries whose citizens have much lower average incomes.
In developing countries environmental problems often stem from what is called a population crisis. This occurs when human populations grow too quickly for the regions to support. This contributes to a situation in which the inhabitants of these countries are struggling to have their basic needs (such as food, clean water, and shelter) met and preservation of the environment is not a high priority.
In developed countries environmental problems are more likely to stem from a phenomenon that is often referred to as affluenza or a consumption crisis. This occurs when people use up, waste, or pollute natural resources faster than those resources can be renewed, replaced, or cleaned up. Currently developed nations use approximately 70% to 80% of the resources used every year even though they comprise only about 20% of the world’s population Slide 6
The ultimate goal of environmental problem solving is to achieve environmental sustainability. A sustainable world is one in which human populations can continue to exist indefinitely with a high standard of living and health.
There are four key conditions that must be met in order for our world to be sustainable. These are widely referred to as the four principles of sustainability.
1) Meet human needs fairly and efficiently, giving priority to basic needs. This involves addressing equity issues of housing, jobs, food, mobility, municipal services, affordable taxes, and quality of life.
2) Reduce dependence upon fossil fuels, underground metals and minerals. This involves a shift to alternative sources of energy such as solar and wind power and to practices that use fewer or no toxic and non-degradable substances such as mercury, lead, and cadmium.
3) Reduce dependence upon chemicals and synthetic compounds. This involves the creation of products and services at home and work, that reduce or eliminate use of chemical and synthetic substances.
4) Reduce encroachment upon nature. This involves minimizing habitat destruction. Slide 7
In order to find accurate and reliable answers to scientific problems scientists employ the Scientific Method. This is alogical approach to solving problems by making observations; constructing a hypothesis; conducting experiments; organizing, interpreting, and analyzing data; and communicating results.
Observations are made using our senses and sometimes equipment that extends or enhances our senses such as microscopes. Observations must be carefully recorded so that they can reliably be used to formulate a hypothesis.
After necessary observations have been made a hypotheses can be constructed. A hypothesis is a testable explanation for an observation, given in the form of a statement. Then, experiments are conducted in order to test the hypothesis under controlled conditions. Data from the experiments must then be organized, interpreted, and analyzed. In this step, raw data is organized into tables, charts, or graphs in order to make it easier to interpret and analyze. Then, the data is evaluated to determine if the hypothesis was supported.
After the scientist has analyzed the data and determined that what has been learned from the work is important enough to be of interest to other scientists, the results must be published in a related scientific journal. Slide 8
In order to solve environmental problems it is important that we understand our environment. For this scientists use two basic types of science:
Pure sciences, such as biology, physics, and chemistry, seek to answer questions about how the natural world works
Ecology is one of the major foundations of environmental science. Ecologists study how living things interact with each other and with their nonliving environments. Slide 9
When making decisions about the environment scientists use many aspects of the scientific method as well as the pure and applied sciences in order to construct an environmental decision making model. This is a model that enables scientists to weigh the positive and negative, short and long term consequences of the decision.
In order to effectively use the environmental decision making model scientists first gather information from all available sources. Then, they determine which of the key values are relevant the the decision at hand. There are several values that must be considered when constructing an environmental decision making model: aesthetic ( how something looks), economic (impact on the economy), environmental (impact on the environment), educational (educational opportunities), ethical/moral (whether the decision is “right” or “wrong”), health (negative or positive impacts on health), recreational (whether it will provide or remove recreational opportunities), scientific (whether it will provide or remove scientific opportunities or knowledge), social/cultural (whether it will impact people socially or culturally). Nthey determine the short and long term consequences, and finally they analyze the data they have collected in order to make a decision.