In the poem "There Will Come Soft Rains" by Sara Teasdale, what is the basic summary and theme of that poem?

"There will come soft rains," written by Sara Teasdale in 1920, shortly after the First World War, is a 12-line poem that describes the beauties of spring in its first six lines,

And frogs in the pool singing at night,
And wild plum trees in tremulous white;

and continues to remark on how indifferent all this beauty is to human beings, who could go extinct without affecting the general harmony:

And Spring herself when she woke at dawn
Would scarcely know that we were gone.

The theme of Teasdale's poem, echoed by Ray Bradbury's story of the same title where it is prominently cited, is that the human race is not as important in the general order of things as it thinks it is:

Not one would mind, neither bird nor tree,
If mankind perished utterly;

In fact, if "the war" that Teasdale casually refers to were to be nuclear, the utter destruction of mankind might well bring with it the end of "bird" and "tree" as well. Even without war, human activity is capable of enforcing vast changes upon nature.

And Spring herself when she woke at dawn
Would scarcely know that we were gone.

is not a couplet that retains much credibility with what we now know about global warming, for instance.

Teasdale's assertion of human insignificance has thus become out of date, even dangerous. It represents an older stream of environmentalist thought that met human arrogance with taunts of impotence rather than with a demand for greater responsibility.