This short paper offers three propositions to help maintain the traditional core of environmental law while also expanding environmental concerns into the frontiers of the field: 1. Environmental law in the heartland and environmental law at the frontiers of the field differ in important ways. 2. The distinctive features of the heartland and frontiers provide important functional benefits for the adaptive development of environmental law in each respective area. 3. Maintaining a distinctive heartland and frontiers of environmental law creates a dialectic relationship between the two that includes tension but also, if properly managed, potential synergies.

The locus of innovation moving forward is likely to be outside of the traditional domain of environmental law--in areas that are at the frontiers of environmental law, but in the heart of related fields such as energy law, corporate social responsibility, and insurance. At the same time, environmental law's heartland will continue to dominate the regulation of environmental harms for the foreseeable future. The future of environmental law therefore will be determined by a dialectic relationship between the heartland and frontiers of environmental law; each playing its own crucial role in the development of the field, in tension but also significantly dependent on the other.