The human-driven loss of species is the subject of Elizabeth Kolbert’s Pulitzer Prize-winning book, The 6th Extinction: An Unnatural History, and the journalist and author addressed a packed lecture hall at Princeton University last week to talk about it.

Hers was not a lecture, however, but a conversation on stage with Stephen Pacala, Princeton Professor in Ecology and Evolutionary Biology; and as such, the talk took a more personal turn.

Asked why she cared enough to write this book, the part of Kolbert’s answer that stuck with me most was not about the “right to exist” -- which all species should have -- but that fact that humans are not having the right conversation about it. “When you have limited resources, what are you going to preserve?” Kolbert asked. “If we lived in a rational world, we might be having that conversation. But unfortunately we don’t.”

To a communicator’s ears, this could be interpreted to mean that a big part of the environmental crisis lies in our inability to talk about the problems rationally. This applies to climate change as much as to endangered species, and this is Kolbert’s approach to the problem: “How can we illustrate this in a way that brings it home? My strategy was to find people doing cutting edge work. I wanted to be out in the field to make this work come alive.” That is what drove her to write some of the most influential works on the environment of our generation. Hopefully, in time to benefit future generations.

But for anyone paying attention, time is running short, in evolutionary terms. The Sixth Extinction was published in 2014. If she wrote the book today, how would it be different? “The sad thing is I could add ten chapters to the book if I wrote it today. It would not be a different book, but unfortunately, it would be a scarier one.”