Last year, Elizabeth Kolbert released her latest excellent book. Her previous volume, “Field Notes from a Catastrophe,” set a high bar for accessible, accurate science writing about environmental issues, but in my opinion, “The Sixth Extinction” surpasses it in several regards. Readers of this magazine will appreciate its solid geologic grounding and perspective, with entire chapters devoted to the end-Ordovician and end-Cretaceous extinctions, as well as sections on the principles of evolution and Earth history. Climate change, the focus of her earlier book, looms large here too, though it is just one of the many threats to the survival of our biosphere that Kolbert covers.