The strangest thing about Chris Turner’s journey from mainstream avatar of the eco-zeitgeist to voice in the wilderness is that he hasn’t changed his message in the slightest. His 2007 bestseller, The Geography of Hope, found an eager audience for its hopscotching tour of places where new modes of environmentally, socially, and, yes, economically sustainable living had already taken root. “Anything that exists is possible,” was his mantra.

In The Leap, he revisits the same ideas — and, indeed, some of the same locations, updating us on the carbon-neutral Danish islands of Samsø and Ærø and the New Urbanism of Lakewood, Colorado, as well as introducing us to new exemplars like Bogotá’s radically revamped bus network. But in a post–economic meltdown world that smirks at the word “hope” (or, worse, “solar panel”), he understands that the existence of these templates isn’t enough if we’re unable or unwilling to implement them. What distinguishes the outposts on his new tour is that they’ve managed to shake off the inertial grip of the fossil-fuelled status quo — to move forward not with self-defeating incrementalism, but with the bold leap of the book’s title.

To help the rest of us follow suit, Turner formulates the Four Laws of Leap Mechanics. You can’t measure the benefits of a new paradigm with the tools of the old, goes one of them: antiquated yardsticks like gross domestic product, for example, which treat the environment as one big externality, tell us that the Exxon Valdez spill sparked an economic boom that made the catastrophe highly beneficial to Alaska. As a result, Turner says, shifting tracks toward a sustainable future requires a battle of “ideas and values as much as economics and statistics,” using the tools of behavioural economics to nudge people past their irrational biases.

As a rhetorical strategy, this seems odd at first — saying, in effect, there’s no possible way of knowing what awaits us on the other side of this chasm, so let’s just focus on convincing as many people as possible to leap with us. This is unlikely to win over doubters — but, improbably, that’s the most liberating part of the book’s message: forget the doubters. Nothing will convince them that change is needed; and anyway, the Laws of Leap Mechanics tell us that most such leaps are launched “with many minds still unconvinced and hearts unwon.”

The rewards of leaping are evident in places such as Vauban, a redeveloped area of Freiburg, Germany, where the residents agreed to forgo private parking other than in a garage on its outskirts, freeing up land for parks, playgrounds, transit, and bike paths; as a result, the neighbourhood’s carbon footprint has been cut to one-quarter of the German average. Turner’s reprise is aimed at others whose hearts are already won, or were won in 2007 but drifted away. Step toward the ledge, he’s telling us. There is no railing.