fergus, ont.–Thomas Homer-Dixon catches a barely audible sound and tilts his head.

"I'm sorry, I may have to jump up here," he says, and runs out of the room.

His four-year-old son, Ben, playing in another part of the house, has spent the night in the emergency room after a tumble on the couch.

"Just like his dad," says Homer-Dixon's wife, Karen Wolfe. "Energetic."

After consoling Ben, Homer-Dixon returns and shrugs.

"Kids," he explains.

Yes, they do tend to complicate things. Especially if you've spent much of your career illuminating the paths that lead to The End of the World.

The marquee hire of the University of Waterloo's Balsillie School of International Affairs last year, Homer-Dixon has built a career by warning us about the worst parts of our own natures. Our violence, our capacity for self-delusion, our destructive greed. All of it adds up to a planet spinning toward environmental and energy crises of Hollywood blockbuster proportions. Few writers tie the dispiriting facts together as compellingly as Homer-Dixon.

It has earned him a reputation for gloominess, one that friends are at pains to dispel.

"The bearers of bad news aren't often welcome at parties," says David Welch, his colleague at the Trudeau Centre for Peace and Conflict Studies at the University of Toronto.

Nonetheless, Homer-Dixon sticks steadfastly to a grim optimism that, as yet, has little concreteness about it. His newly published third book aimed at a general audience – a collection of essays called Carbon Shift, edited by him with Nick Garrison – is yet another designed to scare us sensible. But Homer Dixon says he can't bring himself to consider worst-case scenarios.

Today, the angular 52-year-old academic just looks beat. He's wearing the leisure suit of the creative class – work shirt, khakis, Birkenstocks over thick woollen socks. He leans back in his chair and stares glassy-eyed out over his backyard in Fergus, Ont., a short drive north of Guelph.

"The people who know about this stuff – the real experts – the more they know, the less optimistic they are," Homer-Dixon says. "What should we do? Most of us can't face it. We divide our brains up into compartments. That may be what I do."

"Okay," his readers might reasonably ask, "so who's going to get us out of this mess then?"

Homer-Dixon was raised on acreage outside Victoria. His mother, Shebou (inspired by the French word for "owl"), was a naturalist and artist. One of her impressionistic canvases dominates Homer-Dixon's living room.

His father, Doug, was a forester with an early bent toward conservation. Homer-Dixon spent his youth outdoors, exploring the world around the low-slung home his mother had designed.

Shebou died of multiple sclerosis when Homer-Dixon was 13, a blow that still resonates, leaving father and son alone.

At 17, he graduated from high school and left home in search of work. He toiled on oil rigs and cruised timber. His goal: to buy a Bricklin, the iconic gull-winged sports car. By the time Homer-Dixon got some money together, Bricklin was out of business.

That left him with money to study and travel. Issues of human conflict preoccupied him. Despite his father's warnings about its relative uselessness, Homer-Dixon drifted into political science. Thirty years on, he sees his father's point.

"A lot of contemporary political science, especially the stuff in international relations, isn't worth the powder it would take to blow it to hell," Homer-Dixon says. "My dad was kinda right. On the other hand, it was the only place I could study the kinds of things I was interested in."

He got his B.A. at Carleton, where he established the Canadian Student Pugwash. The Pugwash movement tackled global issues such as nuclear disarmament. This was an early example of Homer-Dixon's habit of organizing, whether it's the available data or those around him.

"It's not as if he's trying to be at the centre of things," says Ian Graham, a childhood friend who joined the Pugwash at Homer-Dixon's urging. "It just sort of happens. He has this ability to identify things that resonate with people."

After Carleton, Homer-Dixon hit the road. He and a friend spent 18 months travelling through crumbling nations and collapsing empires.

"It maximized the difference for us, between our world and theirs," Homer-Dixon says.

They were in the Soviet Union when Brezhnev died. They saw "Whites Only" beaches in South Africa. He was profoundly struck by the tracts of ruined territory he saw in places such as Central Asia and India, the genesis of his ongoing interest in the connection between environmental stress and conflict.

Upon returning, Homer-Dixon was accepted directly into a Ph.D. program at the Massachusetts Institute of Technology. He remembers those early days rapturously, when social scientists and technicians worked together on problems.

After six years in the U.S., Homer-Dixon was hired by the University of Toronto in 1989.

His breakthrough came with a 1991 article for the journal International Security. In it, Homer-Dixon attacked the so-called Cornucopians, thinkers led by economist Julian Simon, who believe that market forces will provide the ingenuity to overcome our problems. Environmental collapse, Homer-Dixon countered, would soon drive world conflict.

"It just cut through so much that I'd been reading," says U.S. author Robert D. Kaplan. "It was so distilled."

Kaplan built his seminal 1994 Atlantic Monthly article, "The Coming Anarchy," around Homer-Dixon's ideas. In the piece, Homer-Dixon, speaking in the midst of Clinton-era euphoria, warns that the world is at a destabilizing crossroads. He uses the analogy of a limousine being driven through the slums. The developed nations are riding inside the limousine. Everyone else is outside in the muck.

The article predicted that future wars would not be stand-up affairs but asymmetric, driven by ethnic hatred and resource shortages. In short, Homer-Dixon delivered a prescient peek into the post-9/11 world.

Suddenly, Homer-Dixon's fame leaped the academic boundary in what he calls "the watershed moment." Two popular books of warning followed: The Ingenuity Gap (2000) and The Upside of Down (2006). The first explored his contention that the gap between problems and their solutions is growing too quickly for human resourcefulness to close. The second laid out all the pitfalls strewn throughout the 21st century, from peak oil to uncontrollable interconnectedness in our economic markets.

In his books, Homer-Dixon approaches these problems with uncommon sang froid, like a visitor from another planet who's popped by to warn us that the neighbours have had enough. In person, he's more pointed.

"If you take any non-mentally handicapped person and give them the job of running the world, they'd do a better job than we're doing collectively."

Homer-Dixon appears to relish his reputation as Canada's Cassandra, the guy warning about complexity run amok and systemic breakdown in, well, everything.

"Depending on which side of the bed you get out of, it's despair or optimism," Homer-Dixon says brightly.

While he may relish the fight, he seems to draw little joy from being right.

His latest book, which consists of six essays by other writers sandwiched between an introduction and conclusion by Homer-Dixon and Garrison, highlights the two freight trains headed toward our species. The first is climate change. The other is fossil-fuel depletion. The conclusions are more downbeat than anything Homer Dixon has written before, ending with a vision of future generations looking back at us with scorn.

In his current thinking, Homer-Dixon has moved away from the narrowness of political science and into the vastness of complex systems theory. It's fertile academic ground, mainly because it has room for all disciplines within its fuzzy boundaries.

In order to continue this work, Homer-Dixon abandoned the University of Toronto for Canada's sexiest new academic destination, Waterloo.

"I didn't talk to anybody at the U of T," he says. "Nobody was very interested in my work. At Waterloo, I do a talk on ingenuity theory and the room's SRO (standing room only). I could do it at U of T and two people would turn up."

Homer-Dixon hopes to recapture some of the multi-disciplinary magic he remembers from MIT. However, his first order of business is a step away from the greater world: He plans to spend the next few years doing the academic research he skipped when writing his two bestsellers and allowing his wife's career to come to the fore.

"I'm going to watch the kids, recharge the batteries," he says.

The couple also plans to use its refurbished landmark home as a salon of sorts for visiting academics. Two great rooms flank the entrance – one for debate and another to warehouse toys.

Distressingly for those who take Homer-Dixon's warnings seriously, he's still some ways off from getting to the cure. In the past, he's been more hopeful than helpful.

When a Globe & Mail review criticized the paucity of suggestions in a review of The Upside of Down, Homer-Dixon retorted that he'd provided the "bold idea" of using the Internet as a gathering place to begin hammering out solutions.

In the end, Homer-Dixon, by dint of his polymathy, is forced to rely on specialists to build the tools. He comes along later to provide the box.

"The solutions to these problems are going to require advanced training in fields neither Tad (Homer-Dixon's nickname) nor I are experts in," says Welch, who will soon decamp U of T and follow his friend to Waterloo. "It's the physicists and biologists and chemists who have to come up with the fixes. But you still need people to make the problem socially relevant." Homer-Dixon envisions one last blockbuster – "a capstone book" – to announce those solutions.

"The last book in my trilogy is going to be about what we should do," he says. "But there are a gazillion books out there about what we should do. If I'm going to do one, it's going to have to be a breakthrough."

How long will that take?

"Well, each book has taken me about six years. And I don't have the idea yet. But I may actually be pretty close."

Six years sounds like a long time, given what the experts cited by Homer-Dixon in Carbon Shift say. NASA climatologist James Hansen believes we may have already surpassed the maximum level of carbon our atmosphere can contain without irreparable damage. The sudden change that ushers in climate disaster could be decades away or a few years. No one's sure.

The most consistently morbid prognosticator may be scientist James Lovelock, an 89-year-old who's assumed the aura of a shaman, owing to his early warnings on climate change. He envisions Europe as an arid desert by 2040. He believes most of us will be sheltering in the Arctic at century's end, by which time a massive die-off will have claimed 80 per cent of the human race.

Does Homer-Dixon entertain the Lovelockian scenario?

"I haven't allowed myself to go there," he says.

At this point, Homer-Dixon has his one-year-old daughter, Kate, cradled in his lap. She's just woken from her nap, bright-eyed and playful.

Homer-Dixon came to fatherhood relatively late, at 48. He's been married for seven years to Wolfe, who's also an academic at Waterloo, studying water-management issues.

"My wife and I used to joke about how tired he was going to be having kids at his age," says his friend, Ian Graham. "And he sounds it. But there's clearly so much joy in it for him, too. He always talked about a family."

Homer-Dixon still gets letters asking him how he can have children, knowing what he knows. He does it by that process of compartmentalization. There's the world his studies tell him is coming. And then there's the one he wants for Kate.

"So here I am, thinking this is a really big problem that's got a lot of components that I think I understand," Homer-Dixon says, absently stroking Kate's head. "And it's not immediately apparent what the solution is. On the other hand, there's this purely emotional, whimsical part of me that refuses to believe that there isn't an answer out there.

"I refuse to believe that I'm a member of a failed species."