Download presentation
Presentation is loading. Please wait.
Published byAnnis Flowers Modified over 9 years ago
1
Introduction to Environmental Science
2
Ch 1 Science & The Environment 1 Understanding Our Environment 2 The Environment and Society
3
Ch 1 Science & Environment Section 1 Understanding our environment –I can define environmental science. –I can compare and contrast environmental science and ecology –I can list the 5 major fields of study that contribute to environmental science –I can describe the major effects of humans on the environment throughout history
4
Section 1 –I can distinguish between renewable and non-renewable resources –I can classify environmental problems into three major categories
5
Introduction to Environmnetal Science How do you define “environment”?
6
Introduction to Environmental Science Environment – –Everything around us, living and nonliving, natural and man-made –Includes the relationships between these parts of the environment
7
What is Environmental Science? Definition of environmental science: the interdisciplinary study of (1) how the earth works, (2) how we interact with the earth, and (3) how to deal with environmental problems Let’s break that down…
8
Definition of Environmental Science EnvironmentalSciene is a broad, interdisciplinary, applied science involving 5 major fields of study: Biology Earth science, Chemistry, Physics, Social Sciences
9
Goals of Environmental Science Understand + solve environmental problems 2 Main areas: –How we use natural resources –How our actions affect the environment Example: How the nesting behavior of bees is influenced by human activities, such as landscaping. Can you give any other examples?
10
Environmental Science Definition of Environmental Science (1)how the earth works How do the four spheres of our planet function naturally to maintain a balance? atmosphere biosphere lithosphere hydrosphere
11
Definition of Environmental Science (2)how we interact with the earth (our impact on the environment) How do we upset the natural balance? How do we use resources? How do we produce waste? What do we do with out waste?
12
Environmental Science Definition of Environmental Science (3) how to deal with environmental problems To reduce or eliminate our unbalancing effect: Decision making Problem solving
13
Why study Environmental Science? Rapid changes in earth’s environment due to human activities can be traced to two “revolutions”:
14
Life has existed on earth for 3.8 billion years Earth well suited for life –Water covers ¾ of planet –Habitable temperature –Moderate sunlight –Atmosphere provides oxygen and carbon dioxide –Soil provides essential minerals for plants But humans are altering the planet; not always in positive ways
15
POPULATION Globally, 1 in 4 people lives in extreme poverty –Cannot meet basic need for food, clothing, shelter, health Difficult to meet population needs without exploiting earth’s resources
16
OVERPOPULATION People overpopulation –Too many people in a given geographic area –Problem in many developing nations Consumption overpopulation –Each individual in a population consumes too large a share of the resources –Problem in many highly developed nations
17
Hunter-Gatherers Humans and our ancestors
19
Hunter-Gatherers 60,000-12,000 years ago Nomadic – followed plants & animals (allowed nature to repair itself) Lived in small groups-impact low Life expectancy – 30-40 years Experts on native plants Low resourse use per person Over-hunting: disappearance of species?
20
Hunter-Gatherers
21
Hunter - Gatherers Collected plants, hunted, fished, and were nomadic, moving with the seasons Pop growth slow due to high infant mortality and shorter life expectancy Small impact on the environment Altered distribution of plants and animals (extinction of large animals) Low resource use per person, migration, and lack of technology allowed environmental repair to occur
22
Discovery of Fire Effect on vegetation widespread & devastating (kept grasslands open) Affected areas where original action not intended (not all environments adapted to withstanding fire) Selective in its effect on species (some can handle fire better than others)
24
Domestication of plants
25
Agricultural Revolution Gradual move from nomadic lifestyle of hunter-gatherers to the farming of domesticated animals and plants Started about 10,000 years ago Led to human population explosion Can you explain why???
26
Agricultural Revolution 12,000-10,000 years ago (end of last ice age) Domestication of: –Plants by women (artificial selection of best grains) (figs, rice, barley, wheat) –Animals (wolves 3000BC, goats & sheep, horses) Longer life span (better food)
27
Deliberate destruction of natural vegetation to cultivate elected crops Forced people to settle in specific places Caused development of towns – led to changes in land use and population growth (500xs as many people as hunting) Created problems for waste disposal People began to accumulate material good
28
Development of harmful chemicals & pesticides Survival of native plants & animals, once vital to survival, became less important Growth of more food, enabling populations to expand Conflict between society more common as ownership of land & water rights became crucial economic issues
29
Encouraged use of domesticated animals in work (ploughing, transport) Large forested areas cleared for farms Created soil erosion, orgrazing, and other environmental problems (collapse of civilization in Tigris-Euphrates river basin through salt contamination in overworked soil)
30
–People settled into communities, cultivated plants & domesticated animals –Provided food for longer, healthier living, but increased environmental degradation –Slash-and-burn cultivation developed in tropical regions (cleared small patches of forests, burned underbrush & left ashes to fertilize soil) –Sustainable cultivation (shifting/ rotational) meant little impact on land
31
slash & burn
35
Archaeological record indicates that plant & animal domestication arose independently in at least 7, and possibly more, separate locales Centers of domestication Dates (years b.p.) Near East/"fertile crescent“11,000 Northern China9,000 Southern China (?) 8,000 Central Mexico 5,750 Peruvian Andes5,250 Papua New Guinea 6-9,000 West Africa 4,500 Eastern No. America4,000
36
Urbanization Large-scale disruption of forests Improvements in human welfare & expansion of human populations beyond limits set by pre-agriculture patterns of life Growth in transportation and polllution problems
37
European Colonization Large scale environmental degradation under colonial exploitation of resources in former colonies in Africa, Latin America, India No regard for environmental consequences Devalued natural resources in colonial states
38
The Frontier Era (1600s) –European settlers considered land a frontier to conquer and settle –Resources were thought to be inexhaustible and the land was viewed as hostile, dangerous, and needing to be conquered
39
PROBLEMS 1. Dependency on few plants--Agriculture made human communities dependent on relatively few plants--the main crops which they grew--rather than on the many different kinds of plants which hunter- gatherers use. 2. Greater vulnerability to weather—
40
Complete dependency on harvest times--To survive, agriculturalists have to gather all their food for the year at one or two or three harvest times, rather than gathering year round. Nothing can be allowed to interrupt the harvest. Agricultural communities became more time- conscious.
41
store the produce of their fields for the rest of the year, protect it from moisture, vermin, and thieves learn to dole out supplies in measured quantities so the community can survive have seed for next year's planting. These conditions created a new kind of life style.
42
4. Need for intense physical labor specialization becomes possible 5. wealth acquires meaning 6.Humans had never before lived in large groups or in densely packed spaces. They had to learn how to do so successfully (perhaps we are still learning how).
43
problem of polluting one's living space need to develop elaborate cultural means of disposing of their dead, or of their food wastes or excrement, or of the wastes of their livestock. Mobile hunter-gatherer groups must necessarily limit the number of children they have to care for at any given time; large families of many children mean more hands to help in the fields. infectious disease, a problem closely related to population growth and to the difficulty of maintaining a clean, healthy living space.
45
Environmental problems began to occur: Habitat destruction Beginning of soil erosion and overgrazing of areas Pollution of natural resources
46
Industrial Revolution
47
Development of machines to do manual/animal labor Led to use of non-renewable energy sources (fossil fuels) that disrupt the balance of our ecosystems (started in mid-1700’s – recent!)
48
Industrial Revolution Industrial-Medical Revolution (about 275 ya; 1700s) Began in England in the 1700s; came to the U.S. in 1800s Shift from reliance on renewable resources (wood) to dependence on machines & nonrenewable fossil fuels Centralized factories began to mass-produce goods Higher standard of living coupled with greater environmental degradation
49
Advancements led to the reduction in number of farmers needed to produce sufficient food more people moving into towns Use of fossil fuels in factory towns led to air pollution from ash and soot Working conditions were often dangerous Because of aliments and working conditions advancements in medicine occurred
50
Industrial Revolution Large scale use of fossil fuels & mineral resources that pollute air, soil & environment Development of new forms of transportation - boosted international trade and made available goods & services in distant locations Created shift from dependence on renewable fuels to dependence on non- renewable fuels
51
Began in England in mid 1700’s Spread to US in 1800’s People lived longer & healthier Environmental degradation increased Factory towns sprang up, people left farms Factory towns grew polluted, noisy, hazardous Coal smoke filled cities
52
Reduced amount of land & labor needed for farming Improved quality of life: electricity, sanitation, nutrition, medical care improved, improved communication through telephone & computer Shift from natural products & medicines to man-made (plastics, synthetics)
53
The Human Population Over Time: Locate agricultural and industrial revolutions…. 1880 1930 1960 1974 1987 1999 2015* Yr. each billion was reached * projected
54
Scale of Environmental Problems Environmental problems are typically categorized by the affected population. Global problems, like global warming and the hole in the ozone layer affect the entire world population. Local problems, such as deforestation or pollution, can occur on a local scale
55
“Spaceship Earth” Earth - a closed system, meaning materials do not enter or leave Limit to resources Damage that occurs stays in the system Energy enters from sun, heat leaves (open system)
56
10 Major Problems Facing Earth’s Environment (from Collapse by Jared Diamond) 1.Destruction of natural habitat 2.Loss of biodiversity 3.Soil damage and erosion 4.Use of fossil fuels as our main energy source 5.Overuse of freshwater resources
57
10 Major Problems Facing Earth’s Environment 6. Release of toxic materials 7. Introduction of “alien” species 8. Release of harmful gases into atmosphere 9. Human population growth 10. Increasing standard of living
58
A tragic metaphor for “Spaceship Earth” ? Easter Island is a relatively small, isolated Pacific island on which there are hundreds of large stone sculptures, indicating that a complex society once lived there Reference on Easter Island, Collapse: How Societies Choose to Fail or Succeed, by Jared Diamond
59
A tragic metaphor for “Spaceship Earth” ? When European explorers arrived in the 1700’s they found a mostly barren landscape, with no trees over 10 feet tall, yet there were hundreds of toppled statues all over the island. The few people living on the island had no horses or oxen, were using grass to build fires and lived a primitive lifestyle.
60
The mystery: How did the Easter Islanders build and erect the statues, why did they do it and what happened to the civilization that accomplished this?
61
A tragic metaphor for “Spaceship Earth” ? Evidence has been pieced together to provide the following explanation: The island was settled by Polynesians from other islands around 400 CE. At that time there were trees, including palms, on the island as shown by pollen studies. There is evidence that land and sea birds were abundant. The human population grew as high as 30,000 as the islanders harvested dolphins and fish for food using wooden canoes. They also ate native island birds and rats. Farms were started to provide more food.
62
A tragic metaphor for “Spaceship Earth” ? Like other Polynesian cultures, society was divided into chiefs and commoners, which were established into clans. On Easter Island, there was collaboration between the clans, but also competition that resulted in building the large stone heads using rock from an island quarry and moving them into place on their territory. One theory is that this process required many workers to move them by pulling them along wooden tracks, possibly on a wooden sled. All of this required a huge expenditure of resources to support the structures and feeding the workers.
63
A tragic metaphor for “Spaceship Earth” ? Eventually, the island was completely deforested, leading to local extinction of many species on which the islanders depended, as well as the loss of the raw materials to sustain their standard of living. Deforestation also led to soil erosion and a decrease in crop yield from farms. Climate change may have contributed to deforestation.
64
A tragic metaphor for “Spaceship Earth” ? By 1680, civil war replaced the organized clans. People survived as best they could, raising more domesticated chickens for food. The statues that had once been erected as a sign of superiority between clans were then toppled over by rival clans, and remained as evidence of the societal collapse when the Europeans arrived.
66
A tragic metaphor for “Spaceship Earth” ? Is this a small scale model of what could happen to our planet? Similarities: overexploitation of resources in a fragile, closed system, with no where to escape, no place to get more resources
67
Environmental Problems 1.Resource depletion –Renewable vs nonrenewable 2.Pollution –Biodegradable vs nonbiodegradable 3.Loss of biodiversity –Habitat destruction –extinction
69
The Good News Jared Diamond writes in Collapse, “While we do face big risks, the most serious ones are not ones beyond our control, …. Because we are the cause of our environmental problems, we are the ones in control of them, and we can choose or not choose to stop causing them and start solving them.”
70
Summary What’s the situation? We depend completely on the environment for survival We are experiencing increased wealth, health, mobility, leisure time Humans change the environment, often in ways not fully understood – unintended consequences Natural systems have been degraded i.e., pollution, erosion and species extinction Environmental changes threaten long-term health and survival
71
“We are the most dangerous species of life on the planet, and every other species, even the earth itself, have cause to fear our power to exterminate. But we are also the only species which, when it chooses to do so, will go to great effort to save what it might destroy” Wallace Stegner
72
Environmental Sustainability The ability to meet current human need for natural resources without compromising the needs of future generations Requires understanding: –The effects of our actions on the earth –That earth’s resources are not infinite
73
Sustainable Development Economic development that meets the needs of the present generation without compromising future generations
Similar presentations
© 2024 SlidePlayer.com. Inc.
All rights reserved.