But what would humans do, she mused, if they stumbled on a situation like this? Well they wouldn’t be satisfied with the generosity of Candyland. The… - Stephen Baxter

The fault is all ours. We have become overwhelming. About one in twenty of all the people who have ever existed is alive today, compared to just one in a thousand of other species. As a result we are depleting the earth.
But even now the question is still asked: Does it really matter? So we lose a few cute mammals, and a lot of bugs nobody ever heard of. So what? We’re still here.
Yes, we are. But the ecosystem is like a vast life-support machine. It is built on the interaction of species on all scales of life, from the humblest fungi filaments that sustain the roots of plants to the tremendous global cycles of water, oxygen, and carbon dioxide. Darwin’s entangled bank, indeed. How does the machine stay stable? We don’t know. Which are its most important components? We don’t know. How much of it can we take out safely? We don’t know that either. Even if we could identify and save the species that are critical for our survival, we wouldn’t know which species they depend on in turn. But if we keep on our present course, we will soon find out the limits of robustness.
I may be biased, but I believe it will matter a great deal if we were to die by our own foolishness. Because we bring to the world something that no other creature in all its long history has had, and that is conscious purpose. We can think our way out of this.
So my question is—consciously, purposefully, what are we going to do?

It seems to me our best hope for getting through the next century or so is to reach some kind of steady state: recycle as much as possible; try to minimize the impact of industry on the planet; try to stabilize the population numbers. For the last five to ten years I have, in my small way, been working toward exactly that goal, that new order. I don’t see that any responsible politician has a choice.
I must say I entered politics with rather higher hopes of the future than I enjoy now.

A lion takes only the last deer in the herd. She does not dream of having so many cubs that the plains would be full of nothing but lions. There are simple laws. Most species figure them out; you are the exception. An ecology of a single species is not viable. A diverse, stable world would provide for you.