This Comment explores the evolution and influence of international environmental norms. One of the present authors, Prof. Armin Rosencranz, in a 2003 article discussed the origin and emergence of these norms. That article identified 20 norms as either prevailing or rising in the field of environmental law and organized them generally in order of their emergence. This Comment provides a comprehensive update, focusing on how 16 of these norms have evolved and continued to influence international environmental law, and sequencing the norms in terms of their broad acceptance and impact on the global landscape of 2018.