Photo: James Duncan Davidson

Writer and political activist George Monbiot (with only three days’ notice, says Bruno!) joins Session 1: “Moments of Truth.” As a young man, Monbiot went off on adventures in the wild as an investigative ecology journalist. When he returned after six years to his life in Britain, he found himself inundated with the mundane, scratching at the walls of his life. He was ecologically bored.

Monbiot had almost accepted his fate as banal Briton when he discovered rewilding, a conservation movement that has come to popularity in the past two decades, and which drastically shifted Monbiot’s perspective of ecological boredom. One of the primary goals of rewilding is the mass restoration of ecosystems, and one way in which that can happen is trophic cascading, in which animals at the top of the food chain affect processes all the way down the food chain.

Monbiot’s gives a classic example: In 1995, wolves were reintroduced into Yellowstone National Park, 70 years after they had been exterminated. Wolves take life, but they also giveth. An unfathomable cascade followed: Deer populations went down, so streamsides and riversides flourished again; trees on the riverbanks quadrupled in height in just six years; bare valleys reverted to aspen and willow; birds and beavers alike flourished; beavers’ dams created habitats for otters, muskrats, fish, frogs and reptiles; and on and on.

And a glorious, unexpected side effect: The wolves altered the rivers themselves. The return of trees reduced the rate of erosion and narrowed the width of the streams, meanwhile creating a greater diversity of pools and riffles. Even on the hillsides, vegetation has begun to recover. The Yellowstone wolves demonstrated that a single species, when allowed to pursue its natural behavior, can transform an entire ecosystem.

Consider the example of whales in the southern oceans. Though the Japanese government has argued that whaling boosts the population of krill and fish, the opposite appears to be true. Declining numbers of whales have an adverse ripple effect on the ocean’s ecosystem. Whales produce an iron-rich manure — “fecal blooms,” as scientists call them — that fertilizes plant plankton; more plant plankton means more zooplankton; more plankton means more food for fish and krill. And, Monbiot suggests, just as wolves have altered the behavior of the Yellowstone rivers, more whales could have changed the composition of the atmosphere for the better, since the plankton fertilized by them absorb carbon and remove it from the atmosphere. It would seem, says Monbiot, there is more and more evidence to support the Gaia hypothesis — that the Earth functions as a coherent and self-regulating system — from an ecological perspective.

Photo: James Duncan Davidson

But what are the limits to rewilding? In Monbiot’s view, it’s not about controlling nature but letting it find its own way. There are a few necessary actions, like reintroducing absent plants and animals and pulling down fences, but in his view rewilding is not a teleological progression, with a correct endpoint or ideal ecosystem. “It lets nature decide,” he says.

But according to Monbiot, the benefits of rewilding are beyond just ecological. Human life itself should be rewilded. This entails not the de-civilizing of modern life, nor the shedding or regression of technology, but a reintroduction of adventure and surprise back into everyday life. Why only focus on wolves, bears, lynx, bison, moose and beaver, all of which are spreading rapidly across Europe already? What about megafauna? Elephant-adapted trees? Lions in Trafalgar Square? “Why shouldn’t all of us have a Serengeti on our doorsteps?” he asks, to laughs and applause.

Monbiot cites moments from his experience — seeing an osprey return to a local estuary for the first time in 400 years, making eye contact with a dolphin as it leapt over his kayak — as awe-inspiring, reintroducing him to “that high, wild note of exaltation after a drought of sensation that had persisted since early adulthood,” a drought he had previously accepted as an inevitable matter of growing up. But the world is much more interesting, surprising and complex than it seems, and drudgery doesn’t have to be our only experience. Rewild, says Monbiot, and “our silent spring could be replaced by a raucous summer.”

George Monbiot’s talk is now available for viewing. Watch it on TED.com »