The care for sustainability is one of the most urgent problems addressed by policy makers. It requires combined effort by multiple players for its efficiency. There are various levels at which different tools of multiple character are being introduced. Eventually, they turn into policies and actions by private businesses and public agencies. These different instruments can be of legislative and regulatory nature introduced on various levels: the UN conventions, communications, policies and protocols, the EU legislation, the Member States, regional and local authorities. As a result, they take a shape of instruments of various types. The range of non-regulatory tools that supplement the regulatory instruments is wide and often takes the form of financial measures. They can be divided into four groups – incentives, tradable instruments, fines and contractual compensations. All these instruments differ in terms of their character, reach and efficiency. Not necessarily being perfect, still, they contribute to the overall re-shift of approach and help transforming the current anxiety for the nature to tangible actions that protect it. The text addresses questions that are not limited to analyses of the efficiency of existing financial tools but also refer to what else could be done to enhance them and make them even more efficient.

The starting point for discussion and analysis of the sources of international law is almost invariably art 38 of the Statute of the International Court of Justice (‘ICJ Statute’), the International Court of Justice being the primary judicial organ of the United Nations. Article 38 lists the sources of international law as comprising treaties, custom, general principles of law, and – as subsidiary means for determining the law – judicial decisions and academic writing. However, in the 75 years since the adoption of the ICJ Statute, newer sources of legal obligation have emerged for the international community. These often involve non-state and intergovernmental actors in their creation. This chapter explores both the traditional and newer sources of international law and assesses how they are adopted and created.