The development of the Precautionary Principle in International Customary Law

The first one of the three core points of the PP (Precautionary Principle) means that a precautionary action is appropriate when there is credible evidence that a particular technology or activity might be harmful, even if the nature of that harm is not fully understood.
This means that decision makers must consider plausible and potential hazards, basing on experience, what is known and predicted. Harm can occur at different levels: cell, organism, population or ecosystem. Impacts may be biological, ecological, social, economic or cultural.
What is sure is that the Precautionary Principle (or approach) received a general recognition and support by the international community, being used in several international agreements and instrument and being recalled by numerous judicial decisions, both national and international. Despite that, it is still not clear what the true meaning of the principle is and what is the role it plays in the international law.

At any rate, despite this uncertainty in its true interpreting and definition, one can assume “the precautionary principle does have a conceptual core” (CAMERON, 1998).
This core finds its root in recognizing that systems are complex and outcomes are not always predictable, so that it becomes important for decision makers to identify the parameters that are used to assess the potential impacts of a proposed activity. Moreover, the standard against which an action’s impact is measured need to be defined and, in this operation, there are two different visions on this operation the “risk evaluation” in the precautionary approach: the “absolutist view” and the “reasonable view.

- The Absolutist view of the precautionary approach.

This first view descends directly from Hans Jonas, who was worried about the “catastrophic risks for the atoms and the gene”. This theory stands around one main imperative: “avoid the catastrophe”59: his idea relies on the concept that when a risk occurs, that can provoke devastating and diffuse damages, one must prevent the realization of the “scenario of the worst”.

Notwithstanding, this condition of total prevention from harm, shown by Jonas, is still only one of the three conditions required from the absolutist view of the concept of precaution. Indeed, the other two regard the guarantee of a “zero risk” policy, pursued in the decision-making processes, and the principle of the “inversion of the burden of proof” on those who commit the action fraught of risk.
The limit of this theory, that aims to avoid any kind of risk by the mean of the instrument of precautions, relies in the second aspect of the precautionary principle theory: the scientific uncertainty. Indeed, so explained, the foreseen catastrophic and harmful scenario to avoid completely is only one.

This restriction of the field of possible harms does not take in account the reality of the facts. In reality, it happens that, due to the lack of a scientifically demonstrated link between the action and the consequences, the harmful probable scenarios are various, and they can only be predicted and imagined, but always with a part of uncertainty in their effective realisation.
The other conditions required by this interpretation of the approach are unlikely to occur as well: the “zero risk” situation, in order to take an action, in fact, cannot exist in the practice. In effect, there will be always a risk’s coefficient in a provision based on empirical sciences knowledges, because this kind of science is, for its same nature, rebuttable and revisable. In addition, if one takes in account the various elements not includable in the range of the scientific knowledges that, at any rate, affect the precision of a prediction, becomes easy to evaluate how difficult can be to predict a complete no-harm situation.

As far as the burden of proof is concerned, in order to demonstrate the harmlessness of a given environmentally risky action, one ends up in the same problem of the “zero risk” requirement. Indeed, as it is not possible to take an action only if there are no predictable risks, in the same way, one cannot ask to any actor to prove the total absence of the risk, for all the same theoretical reasons mentioned above.

As a conclusion, we can definitely argue that, this first vision of the precautionary approach leads to opposite results compared to the proper finalities of the principle. Under this perspective, indeed, it may result as a simple “principle of abstention”, whereas it might result in providing all the criteria in order to undertake the action instead of inhibiting it.

- The Reasonable view of the Precautionary approach.

This is the right way to consider the precautionary principle: as a partial standard, to coordinate with others, in order to decide if to take the probable (not sure) and not scientifically proven, risk linked to an innovative action65.
According to this interpretation, that is the preferable one, the goal of the principle is not to avoid all the possible risks; the point is, instead, to evaluate all the risks and to decide which of them are compatible with the degree of safety and protection accepted by the community.

Accepting this interpretation, then, a likely risk will always remain, but it will be a risk taken by the decision-maker after a comparative analysis of costs-benefits and it will represent the degree considered acceptable by the society in the name of the progress and the development.
This is the notion of precaution adopted by the European Union Commission with the Communication number 2.2.2000 about the Precautionary Principle; principle that is already existing in the EU Treaties at the article 191.2 TFEU (former art.174.2 TCE).

Through the emanation of the text, that we will analyse more deeply in the following passages, the Commission did not have the intention to modify the norm cited above. Indeed, the communication is a proper non-binding internal instrument, which whom the Commission aimed to explain its point of view over the disputed principle and to stimulate the debate among the scholars and experts.
The Commission starts the Communication pointing out that the main goal pursued throw this act is to try to make clear when and how to use the Precautionary Principle. Its approach tends to a use of the principle that allows the “balancing between the freedoms and rights of individuals, industry and organisations with the need to reduce or eliminate the risk of adverse effects to the environment or to health”. Therefore, the interpreting line of the Commission tends to an utilisation of the principle in a way that could not restrict the technological and economic development and, in order to reach this compromise, the Commission underlines some guidelines for the decision-makers to make clear when they can use the principle. The inconvenient the Commission aims to avoid is a recourse to the principle in an indiscriminate way that could assume the shape of a masked protectionism, which is an outcome contrary to the EU finalities. In fact, the recourse to the principle can be anchored to some standards, more or less specific, to establish when a probable damage asks for precaution.

As the Rio Declaration affirms, the main problem a decision maker needs to solve before taking the decision to act or not in precaution, is the one related to the “level” of the risk and environmental harm. It is out of doubt, in fact, that “as long as people walk the face of the Earth, it will not be possible to prevent all levels of anthropogenic environmental damage, which makes it imperative to draw a line somewhere. A failure to recognize this line could introduce a utopian element into the use of the Precautionary Principle, which cannot be sustained.

Having that clear, almost all the formulations of the Precautionary Principle refer to a minimum threshold of harm in which case there will be a necessity (or an obligation) of intervention. Exception to that identification of a threshold of harm are a minor part of international instruments, like the 1988 Baltic Sea Declaration or the 1989 Declaration on Pollution of the Seas, till the 1991 Bamako Convention, which refer to the danger just as “harmful e harm to humans or the environment”. Apart from these cases, the major other legal international instrument, which refer to the principle, try to find out a limit under, or over, what not invoke, or invoke, the precautionary measures. The two main adjectives used to limit the recourse to the principle are:

- Significant harm;
- Serious or Irreversible harm.

The legal source of the first threshold can be found mainly in the 1992 Biodiversity Convention in its Preamble, even though other further agreements have used the same (or very close) adjectives. Using the words of the Biodiversity Convention legislator: “where there is a threat of significant reduction or loss of biological diversity,” precautionary means are recommended. The meaning of the term, beyond its dictionary definitions, has been traced many times with always a degree of uncertainty. Cameron has referred to it as a “non-negligible harm”, whereas by other the definition stays around terms of exclusion of “de minimis” effects.
The International Law Commission, by itself, has provided some additional clues to the meaning of “significant” within the framework of International Environmental Law, noting that in order to pass for significant, harm must be “appreciable” and “tangible”, as opposed to “trivial”. The Commission gives an instance to explain this level of harm, using the example of the pollution changing the chemical or thermic condition of river water. If such case occurs, the possible future harm to the environment as such is not only a hypothesis but relies upon a proven change produced in the nature that could explode in a significant harm.

Regarding the second threshold generally required by the traditional formulations of the Precautionary Principle, the words “serious” and “irreversible”, can primarily find their root in the Principle 15 of the 1992 Rio Declaration. Besides that, many other posterior instruments have referred to these adjectives, as the 1990 Bergen Declaration, the 1992 Climate Change Convention and others. The use of these terms at a national level can be demonstrated by quoting some arguments held before the court (ICJ specifically) by States. For instance in the 1997 Gabcikovo-Nagymaros case, Hungary cited a version of the Precautionary Principle containing a qualifying standard of “serious or irreversible damage” while contending that the damage to its environment, caused by the disputed project, was “irreparable and enormous”.
Coming back to the Commission of the European Union Communication of 2000, through its words the Commission clarifies the distinction between the “risk evaluation”, necessary for a strategy of prudence (more open and less restrictive than the previous interpretation) and the “principle application” (falling within the risk management phase). [...]