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3.0 Sources of international environmental law

International environmental law is an increasingly critical part of the international legal system. As such it has developed within the body of legal rules and procedures that constitute international law. A fundamental question that underpins law generally is what are its sources? Sources of law are the bases of its authority. A foundational source in English and American law for example is the Magna Carta. In legal systems based on the common law, law comprises decisions made by courts, legislation and constitutional documents. The other principal legal system in the world is the so-called Civil Law. In civil law systems the authority of the law is based on legislation and codes of law. Leading European examples of such codes of law are the French (Napoleonic) Civil Code and Germany's Bürgerliches Gesetzbuch (BGB). In distinction to international law, these national systems of law are termed municipal law.

Compared with national law, or municipal law, international law lacks two foundational legal entities: an overall legislative body with powers of enforcement, and a centralised judicial system with empowerment authority. The absence of these two sources of authority, which some assume are a requirement of a legal system, poses a question: Does international law exist? However, the question assumes a simple distinction between national and international law that is, in fact, not so simple. The underlying assumption posing the question overlooks the fact that legislatures, national governments, and courts are themselves creatures of the law. Who enforces the law when the legislature or the government themselves flout the law? However, regardless of the theoretical discussions and disagreements, international law works in actual practice. Prior to the 20th century, international law functioned even without any formal overall stated basis for its rules. International trade, communications and travel all operated with reasonable safety excepting of course when and where there was war. Until the early 20th century, peaceful settlement of disputes was conventionally sought through some temporary body set up by agreement of the parties in dispute such as a Claims Commission or an Arbitration tribunal. Terms under which arbitration proceeded were determined by mutual agreement of the parties through what is technically termed the compromis. (A compromis is an agreement between two or more countries that are in disagreement, to submit their dispute to an arbitrator, a tribunal or court.) An organisation for this purpose is the Permanent Court of Arbitration (PCA).This was established under the Hague Convention for the Pacific Settlement of International Disputes of 1899. Its title is a misnomer in that it is not a court but an organisation to facilitate arbitration and other forms of dispute resolution. As such, the PCA cannot develop a jurisprudence. It was to provide for a jurisprudence that idea of a Permanent Court of International Justice (PCIJ) was nurtured and established through the Council of the League of Nations in the early 1920s. This was the precursor to the International Court of Justice established after the Second World War. Under Article 92 of the Charter of the United Nations, the Court of Justice is the principal judicial organ of the UN (UN 1945).

The Permanent Court of International Justice was the first permanent international body with responsibility for general jurisdiction. Its statute contained 68 Articles including Article 38 which authoritatively stated the legal sources the Court would use and apply (UN 1945). This Article 38 was carried forward into the Charter of the successor, the International Court of Justice as follows:

(1) The Court, whose function is to decide in accordance with international law such disputes as are submitted to it, shall apply:

(a) international conventions, whether general or particular, establishing rules expressly recognized by the contesting states;

(b) international custom, as evidence of a general practice accepted as law;

(c) the general principles of law recognized by civilized nations;

(d) subject to the provisions of Article 59, judicial decisions and the teachings of the most highly qualified publicists of the various nations, as subsidiary means for the determination of rules of law.

(2) This provision shall not prejudice the power of the Court to decide a case ex aequo et bono, if the parties agree thereto.

This wording is identical with the earlier Article 38 except it adds the clause: 'whose function is to decide in accordance with international law such disputes as are submitted to it'. This emphasises that the Court will apply international law in its proceedings. However, paragraph 2 was also an addition to the earlier article. The latin phrase ex aequo et bono means in equity and good conscience. In other words, the Court has the reserved authority to decide a case in accord with equity and fairness rather than according to the strict letter of the law.

In its broadest sense, equity is fairness. As a legal system, equity can be considered a body of law that addresses concerns that fall outside the jurisdiction of common law. The duality of legal judgment based on equity or on common law has a long history. For example, equity and the common law were once opposing values in the English legal system. The common law was created by a judiciary independent from the Crown and was based on the strict interpretation of statutes and precedential cases. Equity was, however, determined by the king's chancellor and thus was considered by many to be arbitrary and a royal encroachment on the power of an independent judiciary. Despite this criticism, equity assumed a permanent place in the English legal system, as the powers of the Chancery became more defined and judgments became consistent enough to be compiled and used as precedent. Despite the apparent lack of clarity and consistency, other legal systems have also recognised the advantages of allowing judges to determine remedies in cases not covered by well-established common law or statutes.

It is important to note that the four categories of sources of law are not set up as a hierarchy. Nor are they entirely exclusive.

The formal sources of law referred to above, are also known as 'hard law' and establish legally binding obligations on states.

By contrast, the concept of 'soft law' is also found in international environmental law. International soft law refers to those norms of international environmental law which are not binding per se, but which play an important interpretive role in the construction and interpretation of principles and rules of formal international environmental law. A universally respected academic lawyer, Sir Robert Jennings, who was also President of the International Court of Justice, claimed he would not recognise a norm even if he should meet one in the street. Some also claim that the notion of soft law is itself soft. However, the concept of soft law, as a legal rule that is not strictly binding but has some legal significance, may be meaningful. Thus guidelines, codes of conduct, and declarations are not binding but, nevertheless, may gain some effect and over time merge into hard law. Examples of the principles of international environmental soft law, which will be discussed more in detail later in the course, are the principle of sustainable development, the precautionary principle, and the polluter pays principle.

The above sources of hard law and soft law in international environmental law create a disparate system of global environmental protection. The following provides an overview of the four categories of sources of law as applied by the International Court of Justice.