Presentation on theme: "Key Themes in Environmental Sciences"— Presentation transcript:
1Key Themes in Environmental Sciences Chapter 1Key Themes in Environmental Sciences
2Major Themes of Environmental Science Human population growthAn urbanizing worldSustainability of our population and all of naturePeople and natureA global perspectiveScience and values
3Human Population Growth The human population grew at a rate unprecedented in history in the twentieth century.Population growth is the underlying environmental problem.Famine is one of the things that happen when a human population exceeds its environmental resources. An example is African Famine.
5An Urban WorldWhen the impact of technology is combined with the impact of population, the impact on the environment is multiplied.In an increasingly urban world, we must focus much of our attention on the environments of cities and on the effects of cities on the rest of the environment.
6Sustainability and Carrying Capacity What is the maximum number of people the Earth can sustain?As of 2013, what is the population of the Earth?
7Sustainability Sustainable resoruce harvest Sustainable ecosystem An amount of a resource that can be harvested at regular intervals indefinitelySustainable ecosystemAn ecosystem that is subject to some human use, but at a level that leads to no loss of species or of necessary ecosystem functions
8Science and ValuesTo make decisions about an environmental problem we:Know what is possible based on scienceChoose the best option based on our values
9Precautionary Principle Precautionary Principle states that we should not wait for scientific proof before taking action to prevent environmental damage.
10Science as a Way of Knowing Chapter 2Science as a Way of Knowing
11Science is a process of discovery Science as ProcessScience is a process of discoveryScientific ideas changeSometimes a science undergoes a fundamental revolution of ideas
12Science as ProcessThe criterion by which we decide whether a statement is in the realm of science:Whether it is possible, at least in principle, to disprove the statement.
13DisprovabilityIf you can think of a test that could disprove a statement, then that statement can be said to be scientific.If you can’t think if a test, then the statement is said to be nonscientific.
18Assumptions of Science Events in the natural world follow patterns that can be understood through careful observation and scientific analysis.These basic patterns and rules that describe them are the same through the universeScience is based on a type of reasoning known as inductionGeneralizations can be subjected to tests that may disprove them.Although new evidence can disprove existing theories, science can never provide absolute proof of the truth of its theories.
19The Nature of Scientific Proof Deductive reasoning:Drawing a conclusion form initial definitions and assumptions by means of logical reasoning.Inductive reasoning:Drawing a conclusion from a limited set of specific observations.
20Measurements and Uncertainty Experimental errors:Measurement uncertainties and other errors that occur in experiments.Accuracy:The extent to which a measurement agrees with the accepted valuePrecision:The degree of exactness with which a quantity is measured
22Observations, Facts, Inferences, and Hypotheses The basis of science, may be made through any of the five senses or by instruments that measure beyond what we can see.Inference:A generalization that arises from a set of observations.Fact:When what is observed about a particular thing is agreed on by all or almost all.
23Observations, Facts, Inferences, and Hypotheses Hypothesis:An explanation set forth in a manner that can be tested and is capable of being disproved.Dependent variable:A variable taken as the outcome of one or more variables.Independent variable:The variable that is manipulated by the investigator; affects the dependent variable.
27Observations, Facts, Inferences, and Hypotheses Theories: Models that offer broad, fundamental explanations of many observationsHypothesis: A possible solution to a problemInference: Inference is the act or process of deriving a conclusion based on what one already knows or on what one assumesFact: Something that actually existsScientific Law: A scientific law or scientific principle is a concise verbal or mathematical statement of a relation that expresses a fundamental principle of science
29Science, Pseudoscience, and Frontier Science Some ideas presented as scientific are in fact not scientific, because they areuntestable,lack empirical support,or are based on faulty reasoning or poor scientific methodology
31Dollars and Environmental Sense: Economics of Environmental Issues Chapter 28Dollars and Environmental Sense: Economics of Environmental Issues
32The Economic Importance of the Environment Environmental EconomicsThe study of relationships of the importance of the environment to the economyIncludes:The impact of environment as a result of economic activityRegulation of the economy and economic processesThe objective of balancing environmental and economic goals of societyDevelopment of economic policy to minimize environmental degradationFinding solutions to environmental problems
33The Environment as a Commons Land or another resources owned publicly with public access for private uses
36Externalities Externality (Indirect Cost) Direct Costs An effect not normally accounted for in the cost-revenue analysis of producers and often not recognized by them as part of their costs and benefitsDirect CostsThose borne by the producer and passed directly on to the user or purchaser
40Evaluation of environmental intangibles is becoming more common in environmental analysis When quantitative, such evaluation balances the more traditional economic evaluation and helps separate facts from emotion in complex environmental problems
41How Do We Achieve an Environmental Goal? Moral suasionDirect controlsMarket processesGovernment investmentMany controls have been applied to the use of desirable resources and the control of pollution
42Marginal Costs and the Control of Pollutants Marginal Costs: the cost to reduce one additional unit of pollutant3 methods of direct control of pollutionSetting maximum levels of emissionRequiring processes and proceduresCharging fees for emission