International environmental law draws from two important sources: international treaties and conventions' and customary international law.
Blodgett, Mark S.; Hunter, Richard J.; and Lozada, Hector R.
"A Primer On International Environmental Law: Sustainability As A Principle Of International Law And Custom,"
ILSA Journal of International & Comparative Law: Vol. 15
, Article 3.
Available at: https://nsuworks.nova.edu/ilsajournal/vol15/iss1/3