I agree. What you say about avihimsā is an appropriate way to regards the environment from the point of view of the Dhamma.
The efficacy of the Dhamma is measured in terms of internal mental purity, with respect to the objective ideal of nibbana.
The efficacy of environmentalism is measured in external environmental purity, with respect to a subjective ideal of a utopian environment.
Avihimsā contributes directly to internal mental purity.
“I hope, Anuruddha, that you are all living in concord, with mutual appreciation, without disputing, blending like milk and water, viewing each other with kindly eyes.” (MN 31)
What is the final conviction that comes when radical attention is razor-edge sharp? That the object of the mind is mind-made (manomaya). (Ven. Ñāṇananda)
"If you have always believed that everyone should play by the same rules and be judged by the same standards, that would have gotten you labeled a radical 50 years ago, a liberal 25 years ago and a racist today." (Thomas Sowell)