The protection of the environment is a cornerstone of intergenerational justice and a main objective of national sustainable development institutions. Different approaches to the protection of the environment are possible. One approach is to consider the protection of the environment in its own right. Examples of international treaties adhering to this approach include instruments for the protection of the ozone layer, forests, biodiversity, and seas. Also, in some national constitutions the protection of the environment is considered as a good in its own right. Another approach to the protection of the environment is a human-centred perspective which defines the environment from the perspective of its value for human beings. Relevant rights under this approach include third-generation/collective rights such as the right to a healthy environment or the right to development, as inter alia enshrined in a number of General Assembly Resolutions.