That has a simple explanation, though. Monarch caterpillars can only survive on milkweed, and we've decimated the amount of milkweed around because we see it as, well, a weed.
We are doing this to us. We are changing the environment to support short-term wants/needs at the expense of its human habitability in the future.
Well, we don't really know what consciousness really is, so it's hard to say that the Earth isn't conscious. After all, who would have thought a complex network of simple neurons arranged in a particular way would be conscious?
Even a cursory definition of consciousness must include the sum total of all of our sensory perception, and without the biome to augment that perception, it is impossible that our consciousness would not shift to accommodate the inclusion and exclusion of whatever difference in our sensory input would give to our experience of being alive.
We would all _be_ conscious (presuming relative health), but if we were all on Pluto, for example, the lack of light would change our consciousness, and for each individual this change would happen at a rate determined by their experience.
Perhaps this change would happen gradually enough for some that it might be considered an artifact of evolving, but certainly the change would begin the instant we left Earth's influence, and what might be considered our 'normal' state.
I realize it's a little (though I detest this term) 'hand wavy' because it's a thought experiment based on zero examples, but we do know that our consciousness is dependent on what we perceive and don't perceive. Hence the question posed by Nagel [1] "what is it like to be a bat?", as bats are cognitively very close to humans (relative to the entire biome), but without eyesight, it is fairly clear that the consciousness of a bat would be different than that of a human.
I recognize that this point is not necessarily the one central to your comment, but I do think it's interesting to remember that if we were not here, we would not be as we are.
[1]https://en.wikipedia.org/wiki/What_Is_it_Like_to_Be_a_Bat%3F
You may want to revisit that assumption.
Being as the science on this subject is changing very rapidly, as we speak.