Chapter 1: Environmental ScienceA Global Perspective

“ All the flowers of all the tomorrows are in the seeds of today.”

Chinese Proverbs

Section 1.1: Understanding our Environment

• What do you think of when you hear the term “environment?” Some people think of a beautiful scene, like mountains or streams flowing through the wilderness.

• The environment is everything around us. It includes the natural world as well as things produced by humans. It is a complex web of relationships that connect us with the world we live in.

What is Environmental Science?

• Environmental science is the study of how humans interact with the environment. Scientists work all over the world to try to find solutions to problems people caused in the past to finding sustainable alternatives for the future.

The Goals of Environmental Science

• One of the major goals of environmental science is to understand and to solve environmental problems. In order to accomplish this goal, scientists study two main types of interactions between humans and their environment. One area of focus is on how we use natural resources, such as water and plants. The other focuses on how our actions alter our environment. In order to study these interactions, they must gather and analyze information from many different fields of science.

Many Fields of Study

• Environmental science is an interdisciplinary science (involves many fields of study.) One important foundation of environmental science is ecology. Ecology is the study of how living things interact with each other and with their nonliving environment. Ex: ecologists study the relationship between bees and the plants they pollinate, environmental scientists investigate how the nesting behavior of bees is influenced by human activities (planting of suburban landscaping).

• Other sciences also contribute to environmental science. For example: Chemistry helps us understand the nature of pollutants; geology helps us model how pollutants travel underground; botany and zoology provides information needed to preserve species; paleontologists study fossils so we can see how Earth’s climate has changed over time and predict how future climate could possible affect future life on Earth.

• Environmentalists may use information from other sciences at any given time. They also use information from the social sciences (economics, law politics, geography) to study human populations. The social sciences help us to answer questions about how people use the park systems to how migration from rural to urban areas may affect local environments.

Scientists as Citizens, Citizens as Scientists

• Studying the environment is vital to maintaining a healthy and productive society, thus environmental scientists are asked to share the information they get with the world.

• How do scientists know what to study?

• Oftentimes, nonscientists make observations about the environment and inquire about them. This prompts the environmental scientists to investigate the issues. For example, middle school students in Minnesota were concerned about all the deformed frogs appearing in Minnesota lakes. In Ohio, some high school students in Dublin were curious about how the endangered box turtles live and what factors affected their nesting and hibernation sites. After careful studies, the students were able to present their findings to city planners in the hope that the box turtle’s habitats would be protected.

Section 1.2: Our Environment Through Time

• Environmental change is not a modern issue. Wherever humans have hunted, grown food or settled, they have changed the environment. (ex: NYC now stands where Native Americans hunted game and gathered food). This change has occurred over the past 300 years. Moreover, the 21st century is a crucial time in human history; a time to find solutions that will allow people all over our planet to live in clean, healthy environments and have all the resources they need for a good life.

Hunter-Gatherers

• For most of history, people were hunter-gatherers (obtain food by collecting plants and by hunting wild animals or scavenging). Early group of hunter-gatherers were small and migrated to find food that came ripe during certain times of the year. Some people in New Guinea and in the rain forests of South America are considered hunter-gatherers even today.

• Early Native American tribes affected the grassland areas by setting fire to the prairies in order to prevent the growth of trees. They kept the areas as open grasslands so they could hunt bison. In addition, hunter-gatherers groups probably helped to spread plant species to areas where those plants did not grow originally.

• Some large mammal species (giant sloths, giant bison, mastodons, cave bears and saber-toothed cats) may have become extinct due to the overhunting of the hunter-gatherers and the rapid climate change in North America.

The Agricultural Revolution

• Eventually, hunter-gatherer groups starting collecting plant seeds and started domesticating some of the animals. The practice of agriculture (the practice of growing, breeding and caring for plants and animals) started in many different parts of the world as a result of these practices over 10,000 years ago. This “agricultural revolution” had a dramatic impact on human societies and their environment.

• It allowed human populations to grow at unprecedented rates. Humans began to concentrate in smaller areas, putting increased pressure on local environments. This agricultural revolution also changed the food we eat. Most of the food we eat today descended from wild plants. At harvest, farmers would collect the seeds from plants that produced the most desirable traits and would plant them the next year.

• Farming was replacing grasslands, forests and wetlands. One of the earliest ways to clear the land was to ‘slash and burn’ the areas. This practice led to soil loss, floods and water shortages. People were practicing poor farming methods and left the area unable to support growth. This caused widespread environmental effects when the soil became water-logged and contaminated by salts.

The Industrial Revolution• For almost 10,000 years the tools of human

societies were powered by humans or animals. In the middle 1700’s, the onset of the Industrial Revolution changed this pattern. People moved from using animal muscle to power the machinery to using running water and fossil fuels (coal, oil). This shift greatly increased the efficiency of agriculture, industry and transportation.

• Large scale production of goods became less expensive than handmade goods, farm machinery reduced the amount of human labor on farms, and fewer people grew their own food, thus increasing populations in urban areas. Food and goods were transported cheaply across great distance by way of motorized vehicles.

Improving Quality of Life• The Industrial Revolution introduced many positive

changes. They made life easier for us but in return, many of the problems that exist today are a result of the Industrial Revolution. The invention of the light bulbs improved our quality of life, agricultural productivity increased, sanitation, nutrition and medical care vastly improved. With every improvement, environmental issues were introduced (pollution, habitat loss).

• In the 1900’s, modern societies started using artificial substances in place of raw animal and plant products (ex: plastics, pesticides, fertilizers).

Spaceship Earth

• Earth has been compared to a ship traveling through space that cannot dispose of waste or take on new supplies as it travels. Earth is essentially a ‘closed system.’ The only thing entering is energy from the sun and the only thing leaving is heat. There are problems associated with this system. Some resources are limited. As populations increase, those resources will be used up. Waste is also produced more quickly than we can dispose of it.

• Environmental problems can exist on different levels: local (where to build a landfill or arguing about the importance of a rare bird or insect), regional (drinking water that may be affected by a polluted river) or global (ozone-depleting chemicals released in one part of the world will impact all people in the world).

Population Growth: A Local Pressure

• Environmental problems have been associated with the agricultural revolution and the Industrial Revolution as a result of the rapid growth of the human population. The development of modern medicine and sanitation also helped the increase in the human population (quadrupled during the 20th century). Producing enough food for such a large population has environmental consequences (habitat destruction, pesticide pollution). Scientists predict that the human population will continue to increase, doubling in the 21st century, before it begins to stabilize.

What are Our Main Environmental Problems

• There are unlimited numbers of environmental problems facing us today; however, almost all environmental problems fall into one of three categories: resource depletion, pollution and loss of biodiversity.

Resource Depletion

• A resource is depleted when a large part of it has been used up.

• Natural resource – any natural substance that living things use (sunlight, air, water, soil, minerals, plants, animals, forests, fossil fuels)

• Natural resources can be classified as renewable and nonrenewable.

Renewable Resources

• Renewable resources are resources that are continually replaced (solar, trees, fish, wind, air, water, soil, crops); but can be depleted if used up faster than it can be replaced, ex: trees.

Nonrenewable Resources

• . Nonrenewable resources are resources that form at a much slower rate and cannot be replaced (fossil fuels like oil, natural gas); when they are used up, they are gone.

• Resources are said to be depleted when a large fraction of the resource has been used up (ex: trees that are harvested faster than they can grow naturally in an area)

Pollution

• The Industrial Revolution began producing wastes faster than the wastes could be disposed of. These wastes accumulate in the environment and cause pollution. Pollution is an undesired change in air, water, or soil that adversely affects the health, survival or activities of humans or other organisms. Most pollution is a result of human activities.

• Two main types of pollutants: biodegradable (can be broken down by natural processes) pollutants and non-biodegradable (cannot be broken down by natural processes) pollutants.

Biodegradable

• Biodegradable pollutant examples would include human sewage or stacks of newspapers. These items present a problem when they accumulate faster than they can be broken down.

Non-Biodegradable

• Non-biodegradable pollutant examples would be mercury, lead and some plastics because they do not break down easily.

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Loss of Biodiversity

• Biodiversity refers to the number and variety of species that live in an area. Only a fraction of the hundreds of millions of species are alive today. All the others are now extinct. Extinction is a natural process, but during the course of history, Earth has experienced mass extinctions (250 million years ago, as much as 95% of all species became extinct).

• Why should we be concerned with extinction of species? We depend on other organisms for food, for the oxygen we breathe and for many other things. When a species becomes extinct, it is gone forever. We have limited information on the current rate of extinction among the species alive today in comparison to organisms in our past. Scientists believe that all species have potential economic, ecological, scientific, aesthetic and recreational value. So, they believe it is in our best interest to preserve all organisms.

We need to consider human societies, how they act and why they do what they do when we think about environmental problems and how could solve them. In order to do that,

we need to look at how a society uses common resources. Ex: a neighborhood

park or the ocean. What do we need to do in order to share those common resources?

• The Environment and Society

Economics and the Environment

• Economic influences influence how we use resources.

Supply and Demand

• One of the basic economics is supply and demand. The greater the demand, the more it is worth. Ex: The relationship between oil production and the price of oil. If the supply of oil decreases, we have three choices: pay the higher price, use less oil or find new sources of energy.

Costs and Benefits• A cost-benefit analysis balances the cost of the

action against the benefits one expects from it and oftentimes, the results depend on who is doing the analysis. To industry, the cost to control air pollution may outweigh the benefits, but to a nearby community, the benefits to have clean air may be worth the high price. Therefore, the consumer will have to determine if they want to pay a higher price for a cleaner product or seek out a cheaper alternative which may not have the same environmental safeguards.

Risk Assessment

• One of the costs of any action is the risk of an undesirable outcome. In order to come up with effective solutions to environmental problems, the public must perceive the risk accurately.

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Developed and Developing Countries

• The decisions and actions of all people in the world affect our environment. But unequal distribution of wealth and resources around the world influences the environmental problems that a society faces and the choices it can make.

• United Nations classifies countries as either:

• Developed – have high average incomes, slower population growth, diverse industrial economies, stronger social support systems (ex: USA, Canada, Japan, countries of western Europe)

• Developing – have lower average incomes, simple and agriculture-based economies, rapid population growth (ex: India, Kenya)

• Some in-between countries are Mexico, Brazil and Malaysia

Population and Consumption

• Almost all environmental problems can be traced back to two root causes:

• Human population in some areas is growing too quickly for the local environment to support

• People are using up, wasting or polluting many natural resources faster than they can be renewed, replaced or cleaned-up

Local Population Pressures

• When populations grow too fast, there are not enough natural resources for everyone to live healthy, productive lives. In overpopulated areas, people struggle for survival (forests are stripped bare, topsoil is exhausted, animals are driven to extinction). People suffer from starvation, malnutrition and disease. Enough with all these things, populations tend to grow more rapidly. Food production, education and job creation cannot keep pace so each person gets fewer resources. Safe drinking water, proper sanitation and having access to enough food are constant struggles in overpopulated areas.

Consumption Trends

• In wealthier parts of the world, life is better than ever before. Pollution controls improve every year, environmental problems are being addressed, and population is stabilizing or is growing slowly. However, to support this way of life, developed nations are using much more of the world’s natural resources than the developing countries.

• Developed countries are using about 75% of the world’s resources even though they only make up 20% of the world’s population. This creates more waste and pollution per person.

Ecological Footprints

• An ecological footprint is a calculation of the amount of land and resources needed to support one person from a particular country. The ecological footprint of a person in a developed country, on average, is four times as large as the footprint of a person in a developing country.

Environmental Science in Context

• Environmental problems are complex. Simple solutions are and sometimes cause more damage than the original problem did.

Critical Thinking and the Environment

• People on both sides of an environmental issue may feel passionately about their cause. Sometimes information gets distorted and people are misled about the issues. Sometimes information is used to make political points or is misrepresented to support controversial viewpoints. The media oftentimes sensationalizes environmental issues or the economic dimension of an environmental issue is oversimplified. It is best if you make your own decisions about environmental issues.

• You must use critical thinking skills to make informed decisions:

• Be prepared to listen to many viewpoints. You will hear many different reasons for the opinions others form. Don’t react to their ideas without trying to understand their viewpoint.

• Identify your own bias. How does it affect the way you interpret the issue?

• Investigate the source of the information you encounter. Question the conclusions that are formed from the data.

• Gather all the information you can before drawing a conclusion.

A Sustainable World

• Most people support one key goal of environmental science: achieving sustainability (the condition in which human needs are met in such a way that a human population can survive indefinitely).

• A sustainable world is not an unchanging world.• Achieving sustainability requires everyone’s

participation: individual citizens, industry, and government. All must cooperate and work together.

Chapter 1, Section 5

• The word science comes from the Latin verb, scire, meaning “to know.” However, science is not just something you know, but something you do.

The Experimental Method

• Most scientists make their discoveries using the scientific method. This method consists of a series of steps that scientists use to identify and answer questions.

First step: Observing

• Someone notices, or observes something and begins to ask questions. An observation is a piece of information we gather using our senses: sight, hearing, smell, touch

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Second step: Hypothesizing and Predicting

• Observations will give us answers to questions, but observation almost always lead to more questions. To answer a specific question, a scientist may form a hypothesis (a testable explanation for an observation.) A good hypothesis is more than a guess; it should make logical sense and follow from what you already know about the situation.

Third Step: Experimenting• Questions that arise from observations often cannot be

answered by making more observations. In this situation scientists usually perform one or more experiments (a procedure designed to test a hypothesis under controlled conditions.)

• Experiments should be designed to pinpoint cause and effect relationships. For this reason, good experiments have two essential characteristics: a single variable (factor of interest) is tested and control is used. To test for one variable, scientists usually study two groups or situations at a time. The variable being studied is the only difference between the groups.

Fourth Step: Organizing and Analyzing Data

• Keeping careful and accurate records is extremely important in science. A scientist cannot rely on experimental results that are based on sloppy observations or incomplete records. Information a scientist gathers most often in numeric form and is called data. Organizing this data into tables and graphic illustrations helps scientists analyze the data and explain the data clearly to others.

Fifth Step: Drawing Conclusions

• Scientists determine the results of their experiments by analyzing their data and comparing the outcome of their experiment with their prediction. Ideally, this comparison provides the scientists with an obvious conclusion. But, oftentimes, it is not obvious and they may repeat their experiment.

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Sixth Step: Communicating Results

• Scientists publish their results to share what they have learned with other scientists. When they think their results are important, they usually publish their findings as a scientific article.

The Correlation Method

• Whenever possible, scientists will use experiments to answer questions; however, sometimes some questions cannot be answered with experiments. Ex: Does smoking cause lung cancer in humans? (unethical and could injury) What was Earth’s climate like 60 million years ago? (we weren’t around then to know)

• When you can’t answer a question with experiments, then you would have to look at reliable associations between two or more events (correlations) to make predictions. Ex: Relative width of a ring on a tree is a good indicator of the amount of rainfall the tree received in the previous year. This method may be useful, but they do not necessarily prove cause and effect relationships between two variables.

Scientific Habits of Mind

• Scientists approach questions in many different ways. Good scientists tend to share several key ways of approaching and thinking about things: curiosity, skepticism, openness to new ideas, intellectual honesty, imagination and creativity.