Download
1 / 73
730 likes | 734 Vues
CHAPTER 1. Science and the Environment. An introduction to environmental science. On Easter Sunday, 1722, Dutch sailors named a remote South Pacific island Easter Island It is the most remote spot on the planet Inhabited by Polynesians who were living primitively
E N D
CHAPTER 1 Science and the Environment
An introduction to environmental science • On Easter Sunday, 1722, Dutch sailors named a remote South Pacific island Easter Island • It is the most remote spot on the planet • Inhabited by Polynesians who were living primitively • The sailors found large stone statues on the island • Evidence of a sophisticated civilization • The past culture and civilization had vanished
Easter Island: the past • Polynesians arrived on the island around 1200 A.D. • It’s an environmentally fragile island • Small, isolated, dry, cold, nutrient-poor • At first, it was abundantly forested • Palms, conifers, and sandalwood • The inhabitants cut trees to • Clear land for agriculture • Provide structural materials • Move the stone heads from the quarries to the sites at which they would be erected
Easter Island: an environmental catastrophe • By 1650, all the trees were gone • The soil washed into the sea • The eroded soil baked, decreasing agriculture • Degraded soil, depleted forest and water resources • Existence became harder • Workers revolted against the ruling religious elites • Workers fought among themselves • Starvation and disease became epidemic • Without trees, no one could leave the island by boat • The population was down to a few thousand by 1722
Easter Island: consequences of degradation • Easter Islanders (Rapa Nui) did not anticipate the consequences of their actions • They suffered terribly from their contacts with the “civilized” world • Visiting whalers infected them with venereal diseases • Peruvian slavers captured them for the slave trade • Smallpox killed many people • By 1877 only 111 Rapa Nui remained • After annexation by Chile, the government enclosed the Rapa Nui in one village
Easter Island: conditions have improved • In the mid–20th century, archaeologists brought attention to the island • Stone statues have been restored • The Rapa Nui regained some control over their destiny • Tourism has developed • But they still depend on imported food • Unemployment and alcoholism are serious problems
Lessons from Easter Island • When the following occur: • A society does not care for its environment • Its population increases beyond the capacity of the land and water to provide food for all • The disparity between haves and have-nots widens • Then, its civilization collapses • Other civilizations collapsed when they failed to recognize the constraints of their environment • Mayans, Greeks, Incas, and Romans • The future is uncertain for Easter Island • Much depends on the efforts of the Rapa Nui
The state of the planet • The world faces four unhealthy global trends (1) Increasing population growth and its detrimental effects on human well-being (2) A decline of vital ecosystem services (3) The negative impacts of global climate change (4) A loss of biodiversity
Increasing populations decrease human well-being • Today, there are more than 6.8 billion persons • The population grew by 2 billion in the last 25 years • 75 million persons are added each year • By 2050, there could be 9.1 billion people • They will have to be fed, clothed, housed, and have jobs • Most population increases will be in developing countries • 985 million experience extreme poverty ($1 a day) • Over 800 million are malnourished • 6 million preschoolers die each year of hunger and malnutrition
Global economic production • Has doubled since 1986 • Average gross domestic product (GDP) in low-income countries has improved • But real income in most developing countries is falling • Because of the large inequalities in wealth between them and developed countries • Stabilizing population growth in developing countries is also essential for closing this economic gap
The decline of ecosystems • Ecosystems support human life and economies with goods and services • These vital resources are not being managed well • Humans are depleting groundwater, degrading soils, overfishing, and depleting forests • The world economy depends on renewable resources • For fresh water, food, fuel, wood, leather, furs, etc. • For raw materials for fabrics, oils and alcohols, etc. • Agriculture, forestry, and fishing are responsible for 50% of all jobs worldwide
Ecosystems provide services • They support human life and economic well-being • Waste breakdown, climate regulation, erosion control, pest management, maintenance of nutrient cycles • These goods and services are “ecosystem capital” • Human well-being and economic development depend on the products of this capital—its income • Goods and services are provided as long as the ecosystems producing them are protected • Ecosystem capital in a nation and its income-generating capacity represent a major form of a nation’s wealth
Global climate change: a serious problem • Global climate change is a current serious problem • Due to the accumulation of greenhouse gases • Carbon dioxide is a by-product of burning fossil fuels • Carbon dioxide is a natural component of the atmosphere • It is required by plants for photosynthesis • It’s important to the Earth’s atmosphere energy system • The greenhouse effect: carbon dioxide absorbs infrared (heat) energy radiated from Earth’s surface, which warms the lower atmosphere
Intergovernmental Panel on Climate Change (IPCC) • Established by the United Nations in 1988 • It reports its assessment of climate change every 5 years • The Fourth Assessment Report (FAR) (2007) • Input from thousands of scientific experts and hundreds of authors • This assessment produced convincing evidence that human-induced climate change is already severely impacting global climate and sea level • Concluded that future changes could be catastrophic if emissions of greenhouse gases are not controlled
The Kyoto Protocol: reducing greenhouse gas emissions • 166 nations met in Kyoto, Japan, in December 1997 • Most industrialized nations agreed to reduce emissions • Ratified in 2005, it is in force in most industrialized nations • The United States, the biggest emitter, withdrew in 2001 • Kyoto is only a first step • Levels of greenhouse gases will continue to rise • Short-term economic impacts conflict with the long-term consequences of climate change • Climate change is one of the defining environmental issues of the 21st century
Environmental science • Human societies live in the natural world • We use materials, converting parts of it into the built environment (towns, factories, highways) • We change natural ecosystems into agricultural ones • We use the environment to dump wastes • The environment: is an inclusive concept • It includes the natural world • Human societies and the human-built world
Environmental science • Environmental science: the study of how the world works • Examines cause-and-effect relationships underlying issues and problems that rise from our use of the natural world • It provides answers that allow societies to make changes consistent with a sustainable future • Encompasses many disciplines • History, engineering, geology, physics, medicine, biology, sociology • It is the most multidisciplinary of all sciences
The early environmental movement • Has its roots in the late 19th century • Unique, wild aspects of the U.S. were disappearing • In 1890, the frontier was closed • No part of the country was totally uninhabited • Conservation groups were formed • National Audubon Society, National Wildlife Federation, Sierra Club • President Theodore Roosevelt placed 230 million acres under public protection • A national environmental consciousness was stirring
The Great Depression and World War II • During the Great Depression, conservation provided environmental protection and jobs • The Civilian Conservation Corps (CCC) built trails, planted trees, and improved national parks and forests • The years after World War II brought technological optimism • Tremendous production capacity and new technology were redirected to peacetime applications • Environmental problems became obvious • Polluted air, fouled rivers and beaches, species declines
The modern environmental movement • Rachel Carson wrote Silent Spring (1962) • She described a future with no songbirds, along with other consequences of pesticide pollution • The modern environmental movement: a newly militant citizenry demanded • Curtailment of pollution • Cleanup of polluted areas • Protection of pristine areas • It began as a grassroots initiative • Continues to command public interest and support
Environmentalism • Wildlife advocates became active in the environmental movement • Environmental Defense Fund, Natural Resources Defense Council, Greenpeace, Union of Concerned Scientists • Environmentalists: persons and organizations with a strong focus on environmental concerns • Environmentalism: the widespread development of the environmental movement
The environmental movement has been successful • Congress created the Environmental Protection Agency (EPA) in 1970 • Congress passed laws for pollution control and wildlife protection • Society has spent billions of dollars in pollution control • Governments have spent billions upgrading sewage treatment and on refuse disposal • The air and water are much cleaner than in the 1960s • Without the environmental movement, our air and water would be a toxic brew
Moving toward sustainability • To move toward sustainability we need: • Sound science: understanding how the world works and how humans interact with it • Sustainability: the goal we should be working toward • Stewardship: managing natural resources and human well-being for the common good
Sound science: the scientific method • Many environmental issues are so controversial, people are left confused • The scientific method: a way of gaining knowledge • Science: all the knowledge gained through this method • Is legitimate, in contrast with junk science: information that is presented as science but is not • Junk science does not conform to the rigorous methods and practices of legitimate science • Sound science involves using the scientific method to understand how the natural world works
The scientific method: observations • The scientific method consists of observation, hypothesis, test (experiment), explanation • Observation: seeing, hearing, smelling, etc. • Can lead to explanations of some natural phenomena • The basis for natural history, astronomy, anthropology, evolutionary biology • Is involved in zoology, botany, geology, comparative anatomy, and taxonomy • Careful observation is the keystone of science • Helps model how the world works
Experimentation • Sets up situations to make systematic observations regarding causes and effects • For example, the atomic theory is a cause-and-effect picture that measured how chemicals react • Similarly, by putting plants and animals into specific situations, responses can be observed and measured • Is limited to things that can be manipulated • Not good for things that happened in the past
Experimentation is usually systematic • Careful accounts are usually kept to have an accurate record of causes and effects • For example, to discover why Indian vultures declined: • Hypotheses (educated guesses) were made about the cause of the decline • Each hypothesis was tested through observation or experimentation • Experimental results showed that a veterinary drug used in livestock killed vultures when they ate carcasses
Theories • Hypotheses tentatively explain how observations are related • A hypothesis becomes a theory only after much testing and confirmation • A theory is logically consistent with all observations • Theories can suggest or predict certain events • Predictions require more experiments, observations, etc. • A theory represents a valid interpretation of reality • When it provides a logically consistent framework for all relevant observations (facts) • When it can be used to reliably predict outcomes
Is one theory as good as another? • Some people argue that a theory is not proven fact • So all theories are equal • But one theory may have overwhelming supporting evidence that contradicts other theories • To evaluate a theory • Ask about its supporting evidence • Does another theory have more or less evidence?
Natural laws • The second assumption underlying science: the universe functions according to certain basic principles • Cannot be proved with absolute certainty • But every observation and test have borne it out • Natural laws: principles by which we can define and predict the behavior of matter and energy • Laws of Gravity, Conservation of Matter, Thermodynamics • The mathematical language of probability and statistics can express theories • Predator-prey relationships, effects of pesticides
The scientific community • Theories are always less than absolutely certain • Some other theory may better explain the data • Our confidence in scientific knowledge should be proportional to the evidence supporting it • There is no single authoritative source that judges the validity of scientific theories • A collective body of competent, experienced scientists establishes what is competent and what is not • Scientific experts analyze their colleagues’ work • This peer review roots out poor or sloppy science
Junk science • The media and public often give equal credibility to opposing views on an issue (e.g., global warming) • Junk science: information presented as scientifically validbut that does not conform to the rigors of true science • Antienvironmental special interests refer to junk science as anything that threatens their preferred viewpoint • True junk science takes many forms: • Picking and choosing only results supporting your idea • Politically motivated distortions of information • Publication of results in unreviewed books or journals
Sustainability • A system is sustainable if it can continue indefinitely without depleting material or energy resources • First applied to sustainable yields in forestry and fisheries • Harvest resources but stay within the capacity of the population to grow and replace itself • Also applies to fresh water, soils, pollution absorption • Sustainable ecosystems: entire natural systems that • Thrive over time by recycling nutrients, maintaining a diversity of species • Use the Sun as a source of energy
Sustainable societies • A sustainable society is in balance with the natural world • Continues for generations • Does not deplete its resource base • Does not produce more pollution than nature can absorb • Many of our interactions with nature are not sustainable • Declining biodiversity and ecosystems • Greenhouse gases • Population growth in developing countries • Energy and resource consumption in developed countries
Sustainable development • Defined by the World Commission on Environment and Development and published in Our Common Future (1987) • Sustainable development: development or progress that meets the needs of the present without compromising the ability of future generations to meet their needs • Development: improvement of human well-being • Developed countries are concerned with environmental sustainability • Developing countries are concerned with economic development
The concept of sustainable development • Incorporates equity: meeting the needs of the present • But future generations are seen as equally deserving • Sustainability means different things to different people • Economists are concerned with growth, efficiency, resource use • Sociologists focus on human needs (equity, empowerment, social cohesion, cultural identity) • Ecologists want to preserve the integrity of natural systems, live within the carrying capacity of the Earth, and deal with pollutants
Transitioning to sustainability needs: • A demographic transition from an increasing human population to a stable one • A resource transition from a growth-obsessed economy to one that protects nature’s income and ecosystems • A technology transition from pollution-intensive technologies to environmentally friendly ones • A political/sociological transition that embraces a stewardly and just approach that eliminates much poverty • A community transition from car-dominated urban sprawl to smaller, more livable cities
Stewardship: the third unifying theme • Actions and programs that manage natural resources and human well-being for the common good • Stewards care for something they do not own • The natural world or human culture • They will pass it on to the next generation • Environmental stewardship • Guides actions benefiting the natural world and people • Recognizes that land ownership is temporary • Stewardship deals with how to achieve sustainability • Actions to take and values and ethical considerations
Who are the stewards? • People who try to stop environmental destruction and pollution • Rachel Carson, who wrote Silent Spring (1962) • Pablo F. Mendoza and Luis Yanza of Ecuador, who demanded that Chevron pay for its petroleum contamination • Ecuador passed stronger environmental laws • They won the 2008 Goldman Prize • Dr. Wangari Maathai of Kenya, who founded the Green Belt Movement • The first Kenyan woman to earn a Ph.D. • Beaten and jailed for protesting government corruption
Stewardship involves everyday people • They care for each other and the natural world • They recycle, buy less-polluting cars, turn off lights in empty rooms, use less energy, don’t engage in conspicuous consumption • They support environmental organizations • They stay informed • They vote for political candidates sympathetic to the environmental movement and sustainable development
