I think the "scientists be complaining," is the discussion of global warming.
It's poetry, not super literal. . Anyway, the maple trees be just a bit duller than the year before, " I think he's referring to the color not being as vivid. Due to the lack of water. Dry season, brings dryer duller color in the trees. Being, "called from his sleep, " is waking from a nightmare. I think the song is just about being kind to one another, and the "simple kindness, " goes along way in this human chaos.