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Written by Elizabeth Jones   
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Tuesday, 19 June 2012

Precautionary Principle

The phrase precautionary principle gets thrown around quite a bit these days, but have you ever thought about what it really means?1 The term “precautionary principle” comes from the German term “Vorsorgeprinzip,” which literally means “foresight principle.”2 The term was formally defined under Principle 15 of the 1992 Rio Declaration:3
Where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing cost-effective measures to prevent environmental degradation.
Although the term "measures" is not entirely clear, it has generally been accepted to include actions by regulators such as the use of statutory powers to refuse environmental approvals to proposed developments or activities. While the precautionary principle may seem like an obscure academic term for academics, it is a useful concept for thinking about any policy or action that involves environmental risk. The principle can be applied to everyday environmental conundrums. Let’s try it out!

BENEFITS FOR THE ENVIRONMENT: The precautionary principle is all about hedging activities that pose a risk to the environment.

BENEFITS FOR YOUR WALLET: The precautionary principle is also all about making decisions that help to avert catastrophe. In making these kinds of decisions, you may be saving yourself a good deal of money in the future, not to mention the generations to come.

The Precautoinary Principle 4

  1. Define Your Scope

    The formulation of the precautionary principle is inherently vague. Under the definition above, there are several terms that are open to interpretation. The triggering factor of an action is the “threat” of serious or irreversible damage. Exactly what constitutes a “threat” is not clearly defined.

    Then, once a “threat” has been triggered, the wording “allows” but “does not require” action to be taken and leaves this open for governments or other decision makers to decide on a case-by-case basis. All of this language ambiguity has lead to multiple “versions” of the precautionary principle. The two most popular versions are the strong version and the weak version.

    The weak version of the precautionary principle is the least restrictive and allows preventive measures to be taken in the face of uncertainty, but does not require them. Weak precaution holds that lack of scientific evidence does not preclude action if damage would otherwise be serious and irreversible.5 As you may now have noticed, the definition listed above from the Rio Summit is a fairly weak formulation.

    In contrast, the strong version of the precautionary principle holds that regulation is required whenever there is a possible risk to health, safety, or the environment, even if the supporting evidence is speculative and even if the economic costs of regulation are high.6 A good example of an application of the strong version of the precautionary principle is this video on climate change: The Most Terrifying Video You'll Ever See.

  2. Apply the Precautionary Principle to a Situation

    One of the best-known applications of the precautionary principle concerns the use of pesticides or drugs. Try your hand at applying the weak and strong version of the precautionary principle to a scenario where you find a bunch of weeds in your yard and are trying to figure out whether to apply pesticides.

    Pesticides and the Weak Version
    In the pesticide example there is a chance that spraying your weeds could damage your crops, harm resident songbirds, or maybe even get on a child’s play toy. Under the weak version of the precautionary principle, you might reason that there is no direct scientific evidence that the pesticide harms other plants or creatures. Therefore you decide to go forward and apply the spray.

    Pesticides and the Strong Version
    Under the strong version of the precautionary principle, you might reason that although there is no scientific evidence that the pesticide harms other plants or creatures, damage to your other crops or contaminating soil and groundwater or other humans is a chance you are not willing to take. Therefore you decide to hold off on the spray and examine alternative methods of taking care of your garden.

    We use the precautionary principle to make decisions about risk all of the time. Once you have the method down, you may find that making decisions with potentially damaging environmental consequences will feel more deliberate and thought through. You will hopefully find yourself erring in the side of caution when it comes to the environment and human health
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3 United Nations Conference on Environment and Development, Rio, 1992 (the "Rio Declaration"):


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Last Updated ( Tuesday, 19 June 2012 )


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