ENVIRONMENTAL SCIENCE Chapter 1 Science and the Environment

ENVIRONMENTAL SCIENCE Chapter 1 Science and the Environment 1. 1 Understanding Our Environment

1. 1 Understanding Our Environment Objectives n n n Define environmental science and compare environmental science with ecology. List the five major fields of study that contribute to environmental science. Describe the major environmental effects of huntergatherers, the agricultural revolution, and the Industrial Revolution. Distinguish between renewable and nonrenewable resources. Classify environmental problems into three major categories.

Introduction n n Our environment is everything around us. The environment includes biotic (living) and abiotic (nonliving) factors. The environment is also a complex web of relationships that connect us with the world in which we live. Energy flow and cycling of matter are constants in any environment on Earth.

Biotic and Abiotic Factors

What is Environmental Science? n n Environmental science is the study of how humans interact with the environment. Environmental science seeks to understand solve environmental problems by focusing on two primary areas of study. n n n How we use natural resources such as water and plants How our actions alter our environment Environmental science is interdisciplinary, meaning that it integrates many different fields of study.

What is Environmental Science? n n n Ecology, an important foundation of environmental science, is the study of how living things interact with each other and with their abiotic environment. Chemistry helps us understand changes in matter which occur in the environment such as the effect of pollutants. Geology helps us to understand the structure of the Earth and how certain pollutants may disperse if released into the environment. Paleontology helps us to understand changes that have occurred in both climate and living forms in the past. The study of population, economics, law, and politics also play an important role in environmental science.

What is Environmental Science? n Five major fields of study contribute to Environmental Science. n n n Biology – the study of living organisms Earth Science – the study of Earth’s nonliving systems and the planet as a whole Physics – the study of matter and energy Chemistry – the study of chemicals and their interactions Social Sciences – study of human populations and their interactions

Our Environment Through Time n Hunter-gatherer societies consist of people who obtain food by collecting plants or hunting (or scavenging) wild animals. n n Hunter-gatherer societies tend to be small groups that migrate with animals or according to season A few hunter-gatherer societies remain today in parts of the Amazon and New Guinea Evidence suggests that Native Americans burned the prairies to keep trees from growing on them so that they would be better suited for hunting Evidence also links the arrival of man in many places with the extinction of large mammals such as mammoth and giant ground sloth

Our Environment Through Time n Agriculture is the practice of growing, breeding, and caring for the plants and animals that are used for food, clothing, housing, transportation, and other purposes. n n n The agricultural revolution began over 10, 000 years ago in many parts of the world and had a major effect on population and the environment A given area of land can support up to 500 times as many people with agriculture than it can through hunting and gathering As populations grew, they began to concentrate in certain areas

Our Environment Through Time n Agriculture is the practice of growing, breeding, and caring for the plants and animals that are used for food, clothing, housing, transportation, and other purposes. Cont’d n n n The plants and animals that we depend on agriculturally today began as wild populations and were selected through the ages for their desirable traits Slash-and-burn agriculture was an early form of converting natural habitat to farmland Civilizations have fallen due to the destructive consequences (erosion, flooding, degradation of soil quality, etc. ) of poor agricultural technique

Our Environment Through Time n The focus of the Industrial Revolution, which began about 300 years ago, was the change of fuel source from animal and water power to the combustion of fossil fuels. n n n Agriculture, industry, and transportation became much more efficient – enough so to revolutionize society Large scale production meant more and cheaper goods and agriculture depended less on large numbers of laborers Motorized vehicles allowed for the cheap transportation of people and goods over long distances

Our Environment Through Time n The focus of the Industrial Revolution, which began about 300 years ago, was the change of fuel source from animal and water power to the combustion of fossil fuels. n n Along with improvements in lifestyle, the Industrial Revolution has introduced many new environmental problems Pollution and habitat loss are becoming greater concerns as human population continues to increase exponentially

Spaceship Earth n n Environmental problems can occur on any scale – global, regional, or local. Earth is an open system with respect to energy, yet a closed system with respect to matter. As light energy is continually bombarding Earth, some of it is radiated out into space as heat and light energy. Some energy is captured and converted to chemical energy by living systems.

Spaceship Earth n n Human population is growing exponentially – which is evident as a “J – curve” on a population graph. The synergistic effects of the agricultural and industrial revolutions along with modern medicine and a growing awareness of sanitation and hygeine have resulted in an exploding human population that most resemble insect populations – just before they crash. Most large mammals exhibit an “S – curve” population growth. As human population grows, so does its need for resources such as food, energy, and space – as well as the production of waste.

Identifying Environmental Problems n Environmental problems can generally be grouped into three categories. n n n Resource depletion Pollution Loss of biodiversity

Identifying Environmental Problems n Natural resources are any materials used by humans. n n A renewable resource, such as water, sunlight, and wood can be replaced relatively quickly by natural processes Nonrenewable resources, such as fossil fuels and minerals are used up at a much faster rate than they are consumed Any resource can be considered to be depleted when a large fraction of that resource has been used up. Pollution is an undesired change in air, water, or soil that adversely affects the health and activity of organisms.

Identifying Environmental Problems n There are two main types of pollutants. n n n Biodegradable pollutants can be broken down by natural processes and may include sewage and newspaper Nondegradable pollutants cannot be broken down by natural processes and may include mercury, lead, and some plastics Biodiversity refers to the number and kind of different species living in an area.

Identifying Environmental Problems n n n It is estimated that there are currently about 13 million species on Earth – just a fraction of a percent that have existed on Earth through time! Several mass extinction events have occurred through time – including the larges of such events a the Permian-Triassic boundary about 250 million years ago when 95% of then existing species went extinct. It is important that we are not the major cause of the next extinction event (in which we may currently be experiencing).

References n n Moss and Lichens http: //www 1. br. cc. va. us/murray/serendipity/Biology/ Activities/Sherando/examples_of_primary_successio n. htm Mountain Lion http: //www. rw. ttu. edu/sp_accounts/mountain_lion/lit erature. htm Waterfall http: //www. rodsguide. com/cataract_falls. htm Kalahari Bushman Catching Ants http: //www. kalaharidesert. com/destination_gallery_Bushmen. asp

References n n Egyptian Farmer http: //www. wsu. edu: 8001/vwsu/gened/learnmodules/top_agrev/5 -Technology/technology 3. html Factory - http: //english. epochtimes. com/news/5 -92/31874. html Customer Service/Information http: //www. vipowernet. net/Customer. Service. asp Growth Curves http: //www. chem. duke. edu/~bonk/Chem 8304/enote 1 405. html

References n Slash-and-Burn Agriculture http: //encarta. msn. com/media_461539708_761 554342_-1_1/Slash-and. Burn_Agriculture. html