Rational choice approaches to customary international law have gained in prominence in recent years. Although becoming increasingly sophisticated, they are not able to explain all phenomena of customary international law. This contribution claims that there are two different types of unwritten...

The paper examines the potential of customary international law to protect global public goods. In particular, it focuses on the question whether customary law can contribute to the mitigation of climate change. The analysis proceeds in the three steps. First, it will have a closer look at the...