Chapter 1 -- Science and the Environment

1. Chapter 1 -- Science and the Environment Section 1 Understanding Our Environment

2. OBJECTIVES • Define environmental science and compare environmental science with ecology. • List the major fields of study that contribute to environmental science. • Describe the major environmental effects of hunter-gatherers, the agricultural revolution, and the Industrial Revolution. • Distinguish between renewable and nonrenewable resources. • Classify environmental problems into three major categories.

3. Like all species on Earth, humans rely on a healthy, functioning planet for air, water, food, and shelter.

4. What Is Environmental Science? • The environment includes all the living and nonliving things with which organisms interact. • It includes: • the continents, oceans, clouds, and icecaps • animals, plants, forests, and farms • remote areas rarely visited by people, • all of the buildings, urban centers, and houses that people have built • the complex webs of social relationships that shape our daily lives.

5. What Is Environmental Science? • Environmental science is the study of Earth’s natural systems and how humans and the environment affect one another • Understanding the interactions between humans and the environment is the first step to solving environmental problems. National Marine Fisheries Service scientists studying whether commercial boats are harming endangered killer whales

6. What Is Environmental Science? • The area of study can range from a small area to Earth’s entire biosphere.

7. Environmental Science vs. Environmentalism • Environmental Science is the objective, unbiased pursuit of knowledge about the workings of the environment and our interactions with it • Environmentalism is a social movement dedicated to protecting the natural world

8. Which of these pictures depicts Environmental Science? Which shows Environmentalism?

9. The Goals of Environmental Science • A major goal of environmental science is to understand and solve environmental problems. • Two main types of interactions between humans and their environment are: • use of natural resources • how our actions alter our environment

10. Many Fields of Study • Environmental science is an interdisciplinary science: it involves many fields of study.

11. Biology • Zoology – the study of animals • Mammalogy – mammals • Ornithology – birds • Ichthyology – fish • Entomology – insects • Herpetology – amphibians & reptiles • Botany – the study of plants

12. Biology (cont’d.) • Ecology – the study of how organisms interact with their environment and each other • a very important field to environmental science • Microbiology – the study of microorganisms

13. Earth Science • Geology – the study of Earth’s surface & interior processes • Paleontology – fossils & ancient life • Climatology – atmosphere & climate • Hydrology – water resources

14. Physics • Physics is the study of matter and energy • Engineering is the science by which matter and energy are made useful to humans in the forms of human-made structures, machines, and products

15. Chemistry • Biochemistry – the chemistry of living things • Geochemistry – chemistry of rocks, minerals, soil, water

16. Social Science • Geography – relationship between human populations and Earth’s features • Anthropology – interactions of biological, cultural, geographical, & historical aspects of humankind • Sociology – human population dynamics and statistics

17. Review of Terms • Ecology-- the study of interactions of living organisms with one another and with their nonliving environment. • Environmental science -- the study of how humans interact with the environment. Ecology forms the foundation of environmental science.

18. Our Environment through Time • Wherever humans have • hunted, • grown food, or • settled, we have changed the environment. • How have these activities impacted the environment through human history?

19. Hunter-Gatherers • Through most of human history, people were hunter-gatherers – they obtained food by collecting plants and hunting or scavenging the remains of wild animals • They did not grow their own food or raise livestock.

20. Hunter-Gatherers • In what ways did hunter-gatherers have an impact on their environment?

21. 3. Effects of Hunter-Gatherers on Environment • Native American tribes set fires to the prairies to prevent the grow of trees -- open grasslands are ideal for hunting bison. • Spread of plants to areas where they did not originally grow • Contributed to disappearance of large mammal species, such as giant sloth, giant bison, mastodons, saber-toothed cats

22. Chapter 1 Hunter-Gatherers Some groups still exist in undeveloped and underdeveloped countries today Kalahari Bushmen and modern technology Hunter-gatherer group in New Guinea

23. The Agricultural Revolution • Agricultureis the practice of growing, breeding, and caring for plants and animals that are used for food, clothing, housing, transportation, etc. • The “Agricultural Revolution”started in many parts of the world over 10,000 years ago – led to dramatic impact on human societies and environment

24. The Agricultural Revolution 4. Effects on humans: • land can support up to 500 times more people when farmed compared to hunting & gathering • populations grew at an unprecedented rate • people began to live in concentrated groups (towns & villages) • changed the food we eat

25. Chapter 1 The Agricultural Revolution How food changed: • modern crops descended from wild plants • farmers planted seeds from plants with the best qualities -- artificial selection • over time, domesticated plants became very different from wild ancestors.

26. The Agricultural Revolution Domestication of Corn

27. The Agricultural Revolution The process of artificial selection in corn:

28. The Agricultural Revolution Effects on the Environment: • Habitats were destroyed -- grasslands, forests, and wetlands were replaced with farmland. • Removal of forest by slash-and-burn can cause soil loss, floods, and water shortages. • Land lost fertility

29. The Industrial Revolution • Began in mid 1700’s • Until then, tools were powered by humans, animals, or running water • With Industrial Revolution, fossil fuels became new energy sources

30. The Industrial Revolution Effects on society: • Greatly increased efficiency of agriculture, manufacturing, transportation • Fewer people grew their own food • Urban populations grew - food shipped cheaply from farms to cities

31. The Industrial Revolution Effects on society, cont’d: • Inventions improved quality of life • Agricultural productivity increased • Sanitation, nutrition, and medical care greatly improved • Led to unprecedented human population growth

33. The Industrial Revolution Negative impacts: • Increased pollution • Greater habitat loss • Artificial substances in use in 1900’s: plastics, pesticides, fertilizers

34. The Industrial Revolution • Much of environmental science is concerned with the problems associated with the Industrial Revolution

35. The Industrial Revolution negative effects on Earth’s waters

36. Chapter 1 Human Population Growth • In the past 50 years, vast amounts of resources have been used to meet the world’s need for food • Environmental consequences include habitat destruction and pesticide pollution

37. Human Population Growth Human Population Growth

38. Human Population Growth • Most scientists think the human population will almost double in the 21st century. • pressure on the environment will continue to increase

39. What are our main environmental problems?

40. Environmental Problems Can be grouped into three general categories: • Resource Depletion • Pollution • Loss of Biodiversity

41. Resource Depletion • Natural Resources are materials and energy sources found in nature that humans need to survive. Examples: water, petroleum, minerals, forests, animals 2 types of natural resources are: • renewable resources • nonrenewable resources

42. Resource Depletion • Renewable resources are naturally replenished over short periods. • Nonrenewable resources are naturally formed more slowly than we use them. The process can take millions of years. • A resource is depleted when a large portion of it has been used up.

43. Resource Depletion

44. Resource Depletion Renewable resources can become nonrenewable if they are used faster than they are replenished.

45. Chapter 1 Pollution Pollutionis an undesirable change in the natural environment caused by the introduction of substances that are harmful to living organisms

46. Chapter 1 Pollution • Takes many forms: can be waste products, heat, noise, radiation • Much pollution is produced by human activities

47. Pollution Two main types of pollutants: 1. Biodegradable -- can be broken down by natural processes Presents a problem only when the pollutant accumulates faster than it can be broken down.

48. Pollution Two main types of pollutants (cont’d): 2. Nondegradable -- pollutant that cannot be broken down by natural processes. can build up to dangerous levels in the environment.

49. Loss of Biodiversity Biodiversity is the variety of organisms in an area measured by: • genetic variation • the variety of species • variety of communities

50. Loss of Biodiversity • Earth has been home to hundreds of millions of species • Only a few exist today – the others are extinct