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.
Through corruption of the Dhamma comes corruption of the discipline, and from corruption of the discipline comes corruption of the Dhamma. This is the first future danger as yet unarisen that will arise in the future. You should recognize it and make an effort to prevent it. (AN 5.79)
Neither traceable in the Discourses nor verifiable by the Discipline, one must conclude thus: 'Certainly, this is not the Blessed One's utterance; this has been misunderstood by that bhikkhu — or by that community, or by those elders, or by that elder.' In that way, bhikkhus, you should reject it. (DN 16)