The speaker of "Environmentalist" sounds worn out by their own voice. They admit they have run out of "pretty discourse," the polished language that might persuade or comfort, and confess that they "go too far in censuring," suggesting their anger or judgment spills over. Yet the conviction underneath stays firm: the world itself is "the true messiah," the thing that deserves devotion and might save us. The poem turns on the blunt question that follows, "but what will change," which hangs there without an answer.
The last two lines shift to an image of the speaker's books opening "thin membranes in a void." Reading and writing feel fragile, almost weightless, set against something vast and empty. The mood is quiet, tired, and doubtful. It is the feeling of caring deeply about the planet while suspecting that words, even sincere ones, may not be enough to shift anything.