I don't know what it means for something to be good for an environment in the absence of people living in that environment.
Perhaps you mean that wild animals (say mammals) would be better off. Many domesticated animals arguably have lives not worth living so would be better off. However, many partially domesticated animals would be worse off; think of the rats in New York City, for example.
I don't know what it means for something to be good for an environment in the absence of people living in that environment.
Why ever not? It means the same thing as it does when humans are there. Good for the environment isn't conventionally defined purely by what is seen by the local humans.
Perhaps you mean that wild animals (say mammals) would be better off.
No. I mean the environment.
A reminder for everyone: on this day in 1983, Stanislav Petrov saved the world.
It occurs to me this time around that there's an interesting relationship here - 9/26 is forgotten, while 9/11 is remembered. Do something charitable, and not patriotic, sometime today.