Is There Such a Thing as ScienceBased Precaution

1
Is There Such a Thing as Science-Based
Precaution?

• Charles Weiss
• Georgetown University
• School of Foreign Service
• Washington DC USA

2
The Precaution Principle More than an Analytic
Tool

• A Slogan and Rallying Cry Better Safe than
  Sorry
• A Valuable Counterweight to Insistence on
  Rigorous Scientific Proof, which is Almost Never
  Available
• A Formal Statement of the Need for Preventive
  Action Even While Risk is Being Clarified

3
A Stimulus to Creative, Constructive Strategic
Thinking

• Careful Exploration of Alternatives
• Monitoring of Impacts
• Research on Alternative Approaches
• Public Participation in Decision MakingEven So,
  Precaution Can Conflict with Other Considerations
  or with Established International Regimes

4
High-Stakes Differences Between US and Europe

• GMOs Is the Science Uncertain Enough to Allow
  Discriminatory Trade Restrictions?
• Climate Is the Science Certain Enough to Justify
  Kyoto Restrictions?

• The US Advocates Science-Based
• Europe Advocates Precautionary Aside from
  Politics, Can These Approaches be Reconciled?

5
What Does Precaution Mean in Practice?

• Can it be a Practical Guide to the Level of
  Certainty Needed to Justify a Given Action?We
  Propose a Framework for Analysis.

6
There are Two Different Formulations of the
Precaution Principle Weak and Strong
7
Weak Formulation of Precaution Principle

• Where there are threats of serious or
  irreversible damage, lack of full scientific
  certainty shall not be used as a reason for
  postponing cost-effective measures to prevent
  environmental degradation. -- Rio Declaration
  on Environment and Development, 1992. (Note
  triple negative.)

8
Strong Version of the Precaution Principle

• When an activity raises threats of harm to human
  health or the environment, precautionary measures
  should be taken authors italics even if cause
  and effect relationships are not fully
  established scientifically . . . The proponent of
  the activity, rather than the public, should bear
  the burden of proof authors italics.--Wingsp
  read Declaration

9
Both Versions of the Precaution Principle are
Inadequate Guides to Action for Two Reasons
10
1. Neither Weak Nor Strong Precaution Specifies
the Degree of Risk Aversion or Acceptance

• What Level of Uncertainty (i.e., What Standard of
  Proof) is Needed to Justify a Given Action?
• This Leads to Confusion Between
• Disagreements over the Certainty of Scientific
  Evidence (A Technical Issue)
• Disagreements over Standard of Proof (A Political
  or Philosophical Issue)

11
2. Precaution Addresses the Risks (and not the
Benefits) Involved in Only One Alternative,
Whereas Practical Decisions Involve a Choice
Among Alternatives, All of Which Have Benefits,
Costs and Risks
12

• Innovation Has Costs and Risks that May be
  Distributed Equitably or Inequitably over Time
• So Does the Status Quo
• Look Before You Leap vs. Nothing Ventured,
  Nothing Gained
• So Precaution May Prevent Desirable Innovations

13
These Defects Weaken the Principle as a Practical
Guide to Decision Making

• When are Precautionary, Discriminatory Trade
  Restrictions Justified in International Trade
  Law?
• How Much Precautionary Action is Justified to
  Overcome a Feared International Environmental
  Danger?

14
The Justified Level of Precautionary Action is
a Function of

• The Degree of Uncertainty Associated with the
  Scientific Evidence
• The Standard of Proof Required to Support a
  Precautionary Action --
• -- Which is in Turn a Function of Ones Level of
  Risk Aversion
• We Have Developed Subjective Scales by Which Each
  of these Can be Measured

15
Scales of Scientific Uncertainty

• Bayesian Probability (IPCC) What are the Odds?
• 90-99 Very Likely
• 67-90 Likely
• 33-67 Medium Likelihood
• 10-33 Unlikely
• 1-10 Very Unlikely
• 0 ImpossibleThis is Fine if Your Audience is
  Comfortable with Numbers but the Vocabulary is
  Subject to Misinterpretation

16
A Complementary Vocabulary Based on Legal
Standards of Proof

• Preponderance of Evidence
• Clear Indication
• Reasonable Belief
• Reasonable Suspicion
• Hunch or Conjecture
• Whim
• Impossible

• Beyond Any Doubt
• Beyond a Reasonable Doubt
• Clear and Convincing Evidence
• Clear Showing
• Substantial and Credible Evidence

. . . Based on the Analogy Between a Scientific
Argument and a Legal Case
17
A Scale of Levels of Precautionary Action

• Research monitoring
• Ban low-benefit, high-damage actions
• No regrets measures
• Measures against most serious aspects
• Expensive, Politically difficult Measures
• Whatever it takes

18
We Can Now Construct Curves to Display
Justifiable Precautionary Action as a Function of
Different Attitudes Toward Risk of Serious and
Irreversible Harm

• Independent Variable Level of Certainty of
  Scientific Evidence
• Dependent Variable Level of Intervention
• Parameter Level of Risk Avoidance
• Solid and Dashed Curves Show the Preferences
  Revealed in Negotiations over Ozone Depletion

19
A Typology of Archetypal Attitudes Toward Risk

• Scientific Absolutist
• Technological Optimist
• Environmental Centrist
• Cautious Environmentalist
• Environmental Absolutist

20
1
2
3
4
5
____ Global O3 Depletion - - - Ozone Hole
21
Reading Across the Graph, We Find that the
Criterion for Discriminatory Trade Measures
Depends on the Degree of Risk Aversion

• Scientific Absolutists Require Clear and
  Convincing Evidence
• Technological Optimists Require Clear
  Indication
• Centrists Require Probable Cause (Reasonable
  Belief)
• Cautious Environmentalists Require Only
  Suggestive Evidence (Reasonable Suspicion)
• Environmental Absolutists Require Only a Hunch or
  Even a Conjecture

22
These Curves Can Clarify Discussion of
Environmental Issues by Allowing Participants to
Distinguish between Disagreements over the

• Level of Scientific Uncertainty, as opposed to
  
• Degree of Risk Aversion

23
Most Real Decisions are Choices Between
Alternative Risky Futures, not Between a Risky
Proposal and a Risk-Free Status Quo

• Besides, Most Situations are Subject to Adaptive
  (Learn as You Go) Management as They Unfold

24
The Choice between Alternative Futures Usually
Depends on their Comparative

• Robustness Can Recover from Unanticipated
  Consequences?
• Manageability
• Compatibility with Values
• Risk vs. Reward Do We Sacrifice Possible Great
  Rewards in Order to Avoid Losses?
• Equity Who Bears Costs and Risks?
• Short vs. Long Term What of Future
  Generations?But How Can These Considerations
  Best be Conveyed to the Public?

25
We Propose a Reasonableness Principle to Balance
and Complement the Precautionary Principle

• Precautionary action should not unreasonably
  interfere with an innovation that promises major
  benefits until the dangers and benefits of this
  technology are well understood.

26
Applied to Proposed Exceptions to International
Trade Rules on Grounds of Environment or Public
Health, The Reasonableness Principle Implies
that States Must Show Evidence Sufficient to
Support a Reasonable Belief that

• Discriminatory Trade Regulations are Needed to
  Avert Serious and Irreversible Harm.
• (This Standard Is Consistent With the Language of
  the World Court Decision In the Beef Hormones
  CaseSanitary Measures to protect human life and
  health must be based on scientific principles
  and not be maintained without sufficient
  scientific evidence)
• Intervention is Needed to Avert Danger from an
  International Environmental Problem that is under
  Negotiation

27
Applied to Proposed Interventions that May Cause
Environmental Harm, The Reasonableness Principle
Implies that Polluters Must Make a Clear Showing
that

• No Harm to Environment or Public Health will
  Result.

28
The Proposed Reasonableness Principle is
Consistent with Emerging International Practice
and Protects Against Excessive Precaution
29

• The Reasonableness Principle is intended to
  ensure that the international system can continue
  to learn from experience and experiment (adaptive
  management), and that improved technology can be
  developed that is both sustainable and
  productive.
• The Reasonableness Principle can be abused, but
  so can the Precautionary Principle we need a
  balance.

30
The Precautionary Principle and the
Reasonableness Principle Complement Each Other
and Frame the Debate.

• Good Science and Precaution Need not Conflict.
  Science-Based Precaution is Good Risk
  Management.