In recent years, variations of the "precautionary principle" have been

     In recent years, variations of the "precautionary principle" have been adopted in international environmental agreements and regulations. Advocates of its use in such contexts hold that where there is a threat of serious or irreversible environmental damage, lack of a consensus regarding the scientific certainty of the threat should not be used as a reason for postponing cost-effective environmental regulations to prevent the damage. Advocates argue that the precautionary principle reinforces commonsense notions of environmental stewardship. Opponents, however, view it as a fundamentally unscientific rule that exploits the public’s fear of the unfamiliar and promotes radical environmental agendas or protectionist trade policies disguised as environmental regulations.

     Advocates counter that the precautionary principle’s application is justified by science's demonstrated fallibility in anticipating environmental hazards such as asbestosis and ozone depletion. Additionally, they say, some potential environmental hazards cannot be predicted with any certainty by existing scientific methods. Thus, the precautionary principle would allow potentially harmful activities to be regulated even if conclusive proof that harm will occur has yet to be established. However, given that environmental regulations entail real costs—e.g., concern with improbable risks can consume resources that could be better applied to higher-probability risks—opponents also note that the precautionary principle can be taken too far.
     
     The distinction between uncertainty and what might be called "true uncertainty" is important to understanding the scope of the precautionary principle. Uncertainty generally refers to situations in which outcomes are probabilistic in nature, but for which a probability distribution can be formulated. True uncertainty refers to situations in which even the probability of an outcome is not known. It is this latter situation with which advocates of the precautionary principle are primarily concerned. For example, trials may be performed to determine the frequency with which a particular gasoline storage tank will fail in relation to its age—an uncertain harm—which in turn may be used to formulate a probability distribution on which to base regulations. Truly uncertain harms, such as global warming, often arise when controlled testing is impossible and there is no experience from which to construct a probability distribution.

1. The final paragraph of the passage functions primarily to

A. provide evidence that supports the argument presented by advocates of the precautionary principle
B. summarize the argument presented by advocates of the precautionary principle
C. provide evidence that calls into question the main argument presented by opponents of the precautionary principle
D. clarify the type of situations to which the precautionary principle would be considered applicable by its advocates
E. provide real-world examples of the appropriate application of the precautionary principle


2. The passage indicates that advocates of the precautionary principle believe that

A. modern science cannot with certainty predict certain environmental hazards
B. opponents of the precautionary principle are motivated by radical political agendas
C. the public’s fear of truly uncertain hazards is often unfounded
D. promoting political agendas is unavoidable when establishing environmental policy
E. activities that pose predictable harms usually need less regulation than do those that are unpredictable


3. In the passage, opponents of the precautionary principle are reported as raising each of the following issues EXCEPT:

A. The precautionary principle is fundamentally unscientific.
B. The precautionary principle is sometimes used to disguise trade policies as environmental regulations.
C. Environmental regulations entail real costs.
D. Advocates of the precautionary principle are primarily concerned with true uncertainty.
E. Environmental regulations are sometimes based on radical environmental agendas.


4. In the passage, advocates of the precautionary principle refer to asbestosis and ozone depletion primarily to

A. suggest that more funds need to be allocated to formulate probability distributions for certain hazards
B. identify environmental hazards that will require more stringent regulation
C. clarify the distinction between uncertainty and true uncertainty
D. provide evidence of the failure of science to anticipate the potential for serious environmental damage
E. suggest that in the face of some potential harms the precautionary principle should not be taken too far