International environmental law is partly binding on sovereign nations, but its enforceability depends on the type of legal instrument and the state’s consent. Treaties and conventions, such as the Paris Agreement or Convention on Biological Diversity, become legally binding only once a country ratifies them, and even then, enforcement mechanisms are often weak or non-punitive.

Customary international environmental law, such as the principle of "no harm" to other states, may be binding regardless of consent, but proving and enforcing such norms is challenging. Many environmental agreements rely on soft law—non-binding commitments like declarations and guidelines—which, while influential, lack legal force.

Furthermore, the principle of state sovereignty allows nations to prioritize domestic interests over international obligations unless clearly bound. As a result, while international environmental law sets important standards and frameworks, its binding nature is limited by voluntary participation and weak enforcement, often leading to inconsistent compliance.