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Introduction to environmental science �
Chapter 3
Li Guangming College of Environmental Science and Engineering Tongji University 1350 196 7237 [email protected]
Environmental risk: Economics, assessment, and management �
Chapter � 3 �
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Characterizing risk �
l Risk n The probability that a condition or action will
lead to an injury, damage, or loss Mathematical formulations
l Environmental risk n Actual or potential threat of adverse effects on living
organisms and environmental by effluents, emissions, wastes, resource depletion, etc., arising out of an organization’s activities
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Decision-making
process and prioritization
% Probability of risk
Consequences of risk
$ Economics
of risk
Decisions
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Risk and economics
l Risk assessment n To estimate the probability of harm to human
or environment that may result from particular management decisions.
n For example • Risk factors
– Smoking 1 – 2 packs of cigarettes per day – Having 200 chest X rays per year – Driving a motor vehicle
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l Risk management n A decision-making process that involves
weighing policy alternatives and selecting the most appropriate regulatory action by integrating the results of risk assessment with engineering data and with social, economic, and political concerns.
l Risk tolerance
l True and perceived risks
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Environmental economics �
l Resources
l Supply and demand
l Assigning value to natural resouces
l Environmental costs
l Cost – benefit analysis
l Comparing economic and ecological systems
l Green economics
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Cost-Benefit AnalysisEnvironmental costs and benefits
TA B L E 3 . 3 C o s t s and Benefits of Improving Air Quality
Costs BenefitsInstallation and maintenanceof new technology:
Reduced deaths anddisease Economic costs and benefits
Scrubbers on smokestacks Fewer respiratory Proposed Alternateproblems action actions
Automobile emissions control Reduced plant andanimal damage
What are the totalmonetary costs of
the project?Redesign of industries andmachines
Lower cleaning costs forindustry and public
Additional energy coststo industry and public
More clear, sunny days;better visibility
Retraining of employees Less eye irritation What are monetaryto use new technology benefits?Costs associated withmonitoring and enforcement
Fewer odor problems
Compare economiccosts and benefits
• - - - ) • • •
Who will cover costs?Who will reap benefits?
Evaluate and comparecosts and benefits
Final decision–consider economicand noneconomic
factors
What environmentalelements and systems
will be affected?1.What will be theconsequences tohuman health and
welfare?
Identify and quantify
Establish monetaryvalues, i possible
What elemen s andsystems cannot begiven a monetary
value?
Identify and quantify
Establish monetaryvalues, if possible
What consequencescannot be given amonetary value?
One particularly compelling critique of cost-benefit analysisis that for analysis to be applied to a specific policy, the analystmust decide which preferences count—that is, which preferencesare the most important for cost-benefit analysis. In theory. cost-benefit analysis should count all benefits and costs associatedwith the policy under review, regardless of who benefits or bearsthe costs. In practice, however, this is not always done. For ex-ample, i f a cost is spread thinly over a large population, it maynot be recognized as a cost at all. The cost o f air pollution inmany parts of the world could fall into such a category. Debatesover how to count benefits and costs for future generations, inan-imate objects such as rivers, and nonhu mans, such as endangeredspecies, are also common.
COMPARING ECONOMICAND ECOLOGICAL SYSTEMSFor most natural scientists, current crises such as biodiversity loss,climate change, and many other environmental problems aresymptoms o f an imbalance between the socioeconomic systemand the natural world. While it is true that humans have always
changed the natural world. it is also clear that this imprint is muchgreater now than anything experienced in the past. One reason forthe profound effect of human activity on the natural world is thefact that there are so many of us.
One o f the problems associated wi th matching economicprocesses with environmental resources is the great differences inthe way economic systems and ecological systems function. Theloss of biodiversity is an example that illustrates the conflictingframeworks of economics and ecology. Market decisions fail to ac-count for the context of a species or the interconnections betweenresource quality and ecosystem functions. For example, from aneconomic point of view, the value of land used for beef productionis measured according to its contribution to its economic output(beef). Yet long before economic output and the use value of landdecrease, the diversity o f grass varieties, microorganisms in thesoil, or groundwater quality may be affected by intensive beef pro-duction. As long as yields are maintained, these environmentalchanges go unnoticed by economic measurements and are unim-portant to land-use decisions. This does not need to be the case. Itshould be pointed out that in Zimbabwe and other African nations,some ranchers now earn more money managing native species of
Environmental Risk: Economics, Assessment, and Management 47
Cost and benefits of improving air quality