We're a murderous species with a capacity for virtue

Elizabeth Kolbert's The Sixth Extinction: An Unnatural History is one scary book. New Yorker stalwart Kolbert wandered the world, interviewing scientists, accompanying their expeditions into remote environments, and listening to their conclusions:

"One-third of all reef-building corals, a third of all fresh-water molluscs, a third of sharks and rays, a quarter of all mammals, a fifth of all reptiles, and a sixth of all birds are headed toward oblivion ... And the losses are occurring all over: in the South Pacific, in the North Atlantic, in the Arctic and in the Sahel, in lakes and on islands, on mountaintops and in valleys.

This book is not another plea that we humans recognize human-caused climate change, though it certainly includes that message. Rather, this book documents that human activity, the ordinary life of our inventive, fertile species, has been and continues to precipitate a mass extinction event of an order of magnitude seen only five previous times in planetary history. That's what we do, mostly inadvertently; we kill off other living things; we might be on the way to killing ourselves off too.

I want to pull out a few conceptual frames that are important in Kolbert's narrative, not so much because they are novel, but because they are helpful to understanding what we can know about the world we live in.

• New Pangea: Three hundred million years ago, scientists believe that the planet had only one land mass, a supercontinent they call Pangea. Over a long, long time span, Pangea broke apart. Evolving life forms ceased to interact and branched off in unique directions. Eventually island continents arose; life forms evolved away from their ancestors even further; eventually the planet threw up (most obviously) Australia with its unique flora and fauna.
  
  Today our ability to move around the world rapidly is bringing together organisms of all sorts that never encountered each other in their original habitats. Often what we label "invasive" species easily supersede (kill off) the former inhabitants. That seems to be what is happening with the rapidly spreading chytrid fungus that is killing many frogs. Rapid dispersal of novel life forms is also, of course, a threat to humans as we carry around previously localized diseases such as eboli, HIV, SARS and now the camel virus MERS. This is the New Pangea.

• Anthomes: Once upon a time, it would have been accurate to describe the planet as consisting of discrete environments -- biomes -- in which evolving humanoids were simply one species among many natives. We called these "grasslands," "rain forests," etc. Now some thinkers use a different mental map for segmenting the planet. No part of the world is untouched by the activities of our species. There is nowhere that is truly "wild." Hence the concept of Anthomes, areas whose environment bears a particular relationship to the activities of the naked ape, such as dense settlements, croplands, and "semi-natural" remnants. This a different way of looking at how life survives, sometimes thrives, and everywhere is undergoing of sort of accelerated struggle to adapt and evolve to the rapid changes we are injecting into the places where it lives.

• the Anthropocene: Geologists, paleontologists, and earth scientists employ a geologic time scale for measuring past events in the planet's history. You've probably heard some of these terms like "Jurassic" or "Paleozoic," etc. If you are not a scientist, you probably never tried to keep them straight. "Anthropocene" has been formally proposed to geologists for adoption as the name for the current "epoch" -- the time frame in which humans have been rapidly altering the planetary reality. Many scientists have adopted this usage.

Kolbert is not sanguine about the future we are creating. She concludes the book with a review of what is known about our ancestor's successful extermination of large animals in the Americas, our present pressure on the few remaining large mammals in the present, and finally, our apparent elimination of close cousin humanoids -- the Neanderthals -- some of whose DNA we carry.

Though it might be nice to imagine there once was a time when man lived in harmony with nature, it’s not clear that he ever really did. ...

... As soon as humans started using signs and symbols to represent the natural world, they pushed beyond the limits of that world. ...

... With the capacity to represent the world in signs and symbols comes the capacity to change it, which, as it happens, is also the capacity to destroy it ....

Yes, this is a scary book. And there can be no question that, unless we deflect ourselves, humans are on a glide path to mass extinction that includes our own. Much destruction is already underway, irreversible. Should we choose to survive what we have made, we'll need to cultivate and make actual the sort of virtues that human thinkers have propounded from ancient times: courage, practicality, prudence, hope and faith. Mere glibness and self-interest aren't enough.