The two books I've read on this topic are " Environmental Ethics, A Very Short Introduction" by Robin Attfield, and "The Intersectional Environmentalist, How to Dismantle Systems of Oppression to Protect People + Planet" by Leah Thomas.

This system of ethics is developing quickly, but it is less than satisfactory as a theory. It uses social theories to propose a theory of nature. This flattens nature into society like other forms of postmodernism. Just like Marx flattened nature into a 'natural resource' internal to society, these theories try to apply human social ethics to non-human nature.

What is needed is a theory of nature beyond society. Nature should have 'value' beyond social constructs. Maybe environmental ethics is a dead end. We a need a theory of environmental science that integrates human and non-human ecosystems without flattening nature into human society by applying human ethics to it.