She began it by announcing that anyone who wished to read the novel as the author intended should look away immediately.
The much-admired American novelist –Orange Prize winning, Pulitzer nominated – tells me this after I confess that I'd like to issue an alert to readers of this interview, because it's impossible to write about her latest book, Flight Behaviour, without spoiling her heroine Dellarobia Turnbow's road-to-Damascus moment, which admittedly comes early on in this magnificent novel – on page 52 to be exact.
When I first read 58-year-old Kingsolver's novel – which is nominated for the Women's Fiction Prize (the prize formerly known as Orange) – I had not read a single review or interview, so Dellarobia's discovery was a revelation. Kingsolver wishes all her readers could read so "naively".
Small, smart and spiky, the flame-haired Dellarobia is 28, trapped in a loveless, shotgun marriage to a gentle farmer, Cub – "dumb as a box of rocks". Barely scrabbling a precarious living on his controlling parents' Tennessee sheep farm, they have two small children.
We first meet Dellarobia when she's frantic with desire. She's wearing ill-fitting, pointed-toed, second-hand boots that were not made for walking. Nonetheless, she's racing up the mountainside to have illicit sex with an almost-stranger, preparing to throw her "good life" away. Then she sees a lake of orange fire, "like the inside of joy". She abandons her tryst, turns around, "seeing straight through to the back of herself". The phenomenon turns out to be millions of tiny monarch butterflies, whose disrupted migration pattern has catapulted them wildly off course, driving them to winter in southern Appalachia, far from their usual Mexican migration spot.
In the depressed Bible Belt of the much-mocked hillbilly culture, the butterflies – "King Billies" as the locals have called them since colonial times, after the royal colours of the Protestant settlers' prince, William of Orange – are seen either as a divine gift or a way to make much-needed cash for the folks of Feathertown, particularly Cub's parents. But for scientist and entomologist Ovid Byron, who arrives to study the monarchs, they signal ecological disaster.
Soon Dellarobia is drawn to the wonders of science and to the handsome, Harvard-educated African-American, who builds a lab in their barn. At first, she believes the burning bush has been put there to save her, and in a way it eventually does. She begins working as Ovid's assistant and "Every day she rose and rose to the occasion of this man." But it is the impact of climate change on a community, an eco-system and a species that is the fulcrum of this ambitious book, with its profound religious subtext, which wears its learning lightly yet is full of amazing facts about the world of science, since Kingsolver was trained as a scientist.
"For several years I've been thinking that someone should write a literary novel about climate change – and that that someone should probably be me because I live in a rural farming community that is being pummelled by climate change – tornadoes, floods, drought. It's like a Biblical plague," explains Kingsolver, a few days after flying into London from her farmhouse home in West Virginia, which she shares with her husband, the scientist Steven Hopp, and daughters, Camille, 25, and Lily, 16.
Kingsolver, who underwent emergency gall bladder surgery recently, is speaking from her hotel room as she is trying to rest between events on her UK book tour. "I actually feel wonderful!" she exclaims.
Writing a novel is like a marriage, she reveals. "It requires a huge commitment – short stories and essays are like dating. But just as in a marriage, writing a novel is 99 parts hard work and one part magic. You always need that spark of imagination. Sometimes I'm midway through a book before it happens. However, I don't wait for the muse to descend, I sit down every day and I work when I'm not delivering lambs on the farm."
Unusually, though, Flight Behaviour, her 14th novel, started with a vision. She always wakes early, around 4am, her head full of sentences impatient to be poured onto the page. "It felt like a dream. I had seen 50 million butterflies sitting in the treetops in the forest on the mountain behind our farm. And I'm enough of a biologist to know what a terrible thing that would mean – and what a circus it would be. I went straight to my desk and made notes. Who would see this vision? It turned out to be a feisty, mad, beautiful housewife, about to wreck her life."
For a long time Kingsolver's working title for Flight Behaviour was Beautiful, Terrible. "It would have been A Terrible Beauty if that weren't already taken, because climate change is going to change and wreck everything. Yet we're all in denial. We still get into our automobiles and drive, we still use our electronic devices."
A phenomenal amount of research went into Flight Behaviour, everything from the life cycle of the monarch butterfly – "an insect as small as a paperclip, with a brain the size of a pin, which migrates thousands of miles to alight on the same tree where its grandmother was born" – to physics, chemistry, biology, psychology and cognitive behaviour. "I wanted to find out why we make up our minds, then collect evidence to support our beliefs, unless we're scientists of course."
Flight Behaviour is a peculiar genre of a novel, she suggests. "It's not science-fiction, nor is it magical realism. It is realism based firmly in real science, but it's about something that has not happened but could. I need readers to trust that this can happen."
Raised in rural Kentucky, Kingsolver studied biology at DePauw and the University of Arizona. She was a journalist, specialising in science writing, before publishing her first novel, The Bean Trees (1988). She's won numerous awards and founded the Bellwether Prize for socially conscious fiction. Her marvellous Pulitzer Prize-nominated book, The Poisonwood Bible (1998), about a missionary family in colonial Congo, became an international bestseller and an Oprah Winfrey choice. Her last novel, The Lacuna, won the Orange Prize in 2010.
Lately Kingsolver, who believes she's a better scientist for having written fiction and vice versa, just as motherhood has made her better writer, has been wondering what her role is in the time she has left. "I'm relatively young in writing terms but time is finite. I know I'm a rare person, a trained scientist who writes fiction, because so few contemporary novelists engage with science."
She always had an obsessive compulsion to write fiction but was too shy to tell anyone. She worried her scientific peers would not take her seriously and that family and friends would think she was getting above herself. "Where I came from, no-one wrote books," she says. "So I wrote in secret."
On the day she brought her first daughter home from hospital, she received a call saying that she had a contract for her first novel. "I was in this hormonal euphoria – I'd just created the most beautiful human life ever! But I couldn't have made it up, could I? From the get-go, motherhood and writing were inextricably linked."
Motherhood is the beating heart of Flight Behaviour. "We so sentimentalise motherhood in popular culture," says Kingsolver, who writes in a clear-eyed way about Dellarobia's exhaustion and frustration at living, trapped in grinding poverty, with small people who constantly run plastic trucks across cereal-encrusted carpets.
But, adds Kingsolver, being a mother has enriched her own life immeasurably. "Ask me what is my greatest work and I'll say, 'I have two. Their names are Camille and Lily.' They've made me understand the world, my connection to it and my sense of the future – and I really love writing children as characters." Which she does as brilliantly as she writes about butterflies.
What are butterflies for, I ask Kingsolver, in my naivety. "You might as well ask a butterfly what people are for," she responds. "I'm sure they'd say, 'People are a pain in our wings.' They pollinate plants, of course. They are beautiful and they are indicators, a reminder of how much we don't know about the mysteries of this marvellous world. Losing them would be like losing the mysteries of the Catholic Church – although I may get in trouble for saying that. But it would be of that magnitude."
And what of that gorgeous human butterfly, the orange-haired Dellarobia, who is such a vital character we never want to abandon her? "I'd love to know her future too," laughs Kingsolver, though there will be no further adventures of Dellarobia. Indeed, Kingsolver is researching her next novel while in London. "There's a clue for you!" she exclaims. "But that's all I'm telling."
And what of our planet's future, given that we seem to be going to environmental hell on a handcart? Is Kingsolver optimistic?
"I'm hopeful," she replies. "I get up every morning and I pull on hope with my boots."
Flight Behaviour by Barbara Kingsolver is published by Faber, priced £7.99. The winner of the Women's Fiction Prize will be announced on Wednesday