Exhausted and exhilarated is how Alan Weisman describes himself while slumped on a couch in a Kensington district boutique inn. As he expresses gratitude for the attention his eco-thriller, science-fantasy book A World Without Us is getting, he recalls the research as being more exhilarating. Even though, he adds, some of the reactions the book has prompted at readings get his blood pumping, too.

What would the world be like if humans — all of us, from rainforest dwellers to urbanites in highrises — suddenly left this planet? Weisman provides a thought-provoking glimpse. He wanted to be a scientist but could never settle on one specialty, so he became a science writer. His writing shows his fascination and deep understanding of scientific processes, and his presentation of the consequences of how we are treating the planet is delivered without judgment.

A Fulbright scholar, acknowledged for his creative non-fiction writing, Weisman’s “what would the world be like without us?” question proved so intriguing, scientists and industry leaders enthusiastically joined in the conjecture. “With the exception of the petrol industry, in the beginning, and that is unfortunate, because it continually has accidents,” he says.

In dealing with the oil and gas industry, he recalls that though initial contacts would be willing to grant interviews, secondary exchanges would come from lawyers followed by endless delays. But he talked with almost everyone whose expertise might reveal an answer, including the creators of polymers and plastics, expounding on their proliferation, prevalence in our everyday lives and near indestructibility. “My intent is to open up the imagination for readers and those who use, maintain and live in this world,” he says. “What I needed to do was find a way to write without pulling punches about the situation. I wanted to interrupt the guilt cycle and defuse the fear factor, to give readers an opportunity to settle in and glimpse the future. It’s a fantasy, but with solid science writing based on educated guesses. How much could nature recover? What would be left, if anything? What have we done that would be indelible?”

Weisman wrote an article for Harper’s Magazine in which he described how, after humans left Chernobyl, the ecosystem ignored the plutonium around the defunct reactor and created a new ecosystem. Several years later, Josie Glausiusz, an editor at Discover magazine, asked him to consider what would happen if humans disappeared, and he began to write the book.

Despite visits to disaster areas across the globe, Weisman remains optimistic. “I’m pretty comforted to think life will go on, on Earth,” he says. “Humans deserve to be on this planet, but we have to bring ourselves into better balance with nature. We don’t have enough clean technology to run our society. We have to think about limiting the numbers of ourselves. We have limited time to solve our problems.

“I’m comforted to know that life is such a miracle,” he adds. “Place after place around this planet, I saw that life is indomitable — a seed growing in a crack heaves a bridge.”