I really think you give humans too much credit here. The world has been here for billions of years, and will be here for billions more. Even if we bombed ourselves to extinction, in another million years there'd be little more to mark our passing than some fossils and a few hunks of concrete.
BUT the spirit is:
>we are the only thing on the planet capable of causing the end of the world, such as it is.
Meaning, we are the only thing on the planet capable of willingly causing our own extinction. This, for all intents and purposes, is the end of the world. World, again, in this context refers to humans and the human experiment.
I don't get the argument that "oh, you mean the death of all humans, the planet will be fine". How is that better? We still all die.
But I think gp meant the end of the world as the end of survivable conditions for humans. Nobody cares if the planet is still here after we are gone.
I am not ungrateful for our current actualization. Getting here took (and continues to take) tremendous sacrifice.