Author Elizabeth Kolbert calls climate change the crucial issue of our time.

“Unfortunately, it’s a story that only gets more truer as time goes on, and more urgent and bigger,” she said.

Kolbert’s book, The Sixth Extinction: An Unnatural History, explores the five mass extinctions that have occurred over the last half a billion years. The sixth one, according to Kolbert’s book, will be us.

“It’s one of those books that’s a science book, and it’s a non-fiction book. But to me, it really reads almost like a fiction story of these different extinctions,” Chicago Public Library’s Jennifer Lizak said.

Lizak leads the committee that narrows down a list of books every year to the final “One Book, One Chicago” pick.

And, yes, Mayor Lori Lightfoot signs off on the choice.

Every year, the selection follows a theme that guides panel discussions, lectures, film screenings and other events. The Sixth Extinction: An Unnatural History fits the category of “Season for Change,” Lizak said.

She said the library’s programming will include lectures about reducing energy use, art projects that explore the complex feelings around climate change and tours of Chicago neighborhoods where residents are making positive impacts on their environment.

Kolbert is excited that her book is headlining the 30th season of “One Book, One Chicago.”

“To get a whole city’s worth of readers and citizens thinking about what I think is really the crucial issue of our time seems like an incredible opportunity to get a conversation going,” Kolbert said.

Chicago Public Library’s Lizak pointed out there are several ways, beyond reading, to engage with “One Book, One Chicago.”

“People sometimes think it’s funny when I say this, but a lot of times, some people won’t even read the book, but they’ll come to the program,” Lizak said.

For those interested in reading The Sixth Extinction: An Unnatural History, Lizak said there are about 1,000 copies of the book, available in several formats, distributed among Chicago’s 81 neighborhood branches.

Carrie Shepherd is a news reporter for WBEZ. Follow her on Twitter at @cshepherd.