“It’s the point of no return,” Dr. Arne Mooers says, emphasizing his words calmly with his hand. “You push, and suddenly – ‘Whoosh!’”

The evolutionary biologist’s hand suddenly plummets, as off a cliff. “We don’t know how fast the transition would be,” he adds, pausing. “No idea.”

Mooers, an evolutionary biologist at Simon Fraser University (SFU), explains the theory behind a ground-breaking report he co-authored in the respected scientific journal Nature this week, Approaching a state shift in Earth’s biosphere.

Scientists have reached near-total consensus on climate change. But according to the new study, once you add other variables – such as population growth, over-consumption, agriculture and extinctions – to that mix, the entire ecological system may teeter on the brink. Everything could, in fact, change in the proverbial blink of an eye (at least, on the scale of earth’s history). It’s called a “global state change,” and the report estimates it could begin as early as the second half of this century if we stay on our present course.

“It’s bad enough for there to be gradual change, but if that change is sudden and irreversible, all bets are off,” Mooers told the Vancouver Observer in an exclusive interview. “If something changes like the temperature, it could then cause a topsy-turvy, upside-downness that causes a new earth.

“A state change in one place could propagate globally like an epidemic. Think about it – think of different ecosystems coming close to a state change. Does that one tip over and cause the next one to tip over, and so on? When about 60 per cent of the earth is converted, that’s a magic number in simple systems, for when an epidemic, rather than fizzling out, sweeps through the entire system.”

Until now, climatologists have documented the effects of carbon dioxide emissions on rising global temperatures – and their predictions are dire. But according to the new review, which compiles existing data into a new mosaic, the earth could suddenly and irreversibly shift in a catastrophic chain reaction, once humans have impacted a majority of the planet’s ecosystems.

Based on the theory that changing systems can reach a rapid “tipping point” – like an iceberg suddenly flipping, or an epidemic exploding – the study’s historic collaboration of 18 paleontologists, computer modellers, mathematicians, biologists and ecologists put their heads together to study whether such state changes could happen on a global scale.

“I would agree that it’s fairly dramatic,” Mooers admits, as we chat in his lab at SFU’s Interdisciplinary Research in the Mathematical and Computational Sciences Centre. “At some point we’ve converted too much of the earth, and the effects will be global.

“This review is dramatic – it’s quite stark. The earth may become a much more hostile place for everyone. . . The chances are that this transition would not only be extremely problematic to human society, but the new state might not be conducive to human society at all.”

The Nature article was released in time for the United Nations International Conference on Sustainable Development, or Earth Summit. Dubbed “Rio+20” to mark the anniversary of the first international environment conference in 1992, tens of thousands of political, scientific and civil society leaders are gathered in Rio de Janeiro, Brazil from June 20-22 to deliberate on climate change and the environmental crisis.

The Earth Summit coincides with an alternative People’s Summit, where environmental and social justice movements will converge and offer critical perspectives.

“All of those things are knowns,” said Steve Price, conservation science director with the World-Wide Fund for Nature (WWF) Canada, when asked about the study’s conclusions. “In some ways, it doesn’t state anything from a factual point of view what we haven’t heard before – rising carbon emissions, a landscape highly dissected with roads, the large conversion of the planet to agriculture, urban and other uses.

“What they’ve done that’s the most interesting is weave these all together, and say there’s a dramatic state shift ahead for the earth. . . That’s what’s frightening – the catastrophic nature of what they say may be ahead.”

The cause of such a catastrophic “state change,” the Nature study concludes, is human activity – from farming to industry, from carbon emissions to habitat destruction. Studied as a whole, the devastation wrought by human industry and population growth have become “global-scale forcing mechanisms,” the authors argue. The report describes such mechanisms as “sledgehammers” in their impact.

“Humans now dominate Earth, changing it in ways that threaten its ability to sustain us and other species,” the report argues. “Planetary-scale critical transitions have occurred previously in the biosphere, albeit rarely, and . . . humans are now forcing another such transition, with the potential to transform Earth rapidly and irreversibly into a state unknown in human experience.

“Anticipating biological surprises on global as well as local scales, therefore, has become especially crucial to guiding the future of the global ecosystem and human societies.”

One of the key research areas behind the findings is paleontology, the study of prehistoric life. Evidence from earlier epochs suggests that previous major climatic changes – such as the 100,000-year long last ice age, and its demise in a single millennium – can be relatively swift, rather than gradual.

As a scientist, is he worried?

“Does it worry me?!” he says, responding to VO’s question as if it is all-too obvious. “Yes, it worries me a lot.

“One of the reasons it worries me a lot is that . . . paleontologists who study past shifts are very, very worried. They’ve seen changes occur, and they’ve been able to document how life has changed on earth.

“Then you lay all the other stuff on it – the social unrest, the land conversion, and so on. I’ve been really worried for a long time. The biggest worry, of course, is that you get all these things happening at once.”

The collaboration began with an invite from University of California-Berkeley paleontologist Anthony D. Barnosky, author of Heatstroke: Nature in an Age of Global Warming.

“A lot of these people are famous names in their own field, but I never thought about them all speaking to this one question,” Mooers said. “There’s no other paper that has these big names in paleontology, in theoretical ecology, in food web theory, in applied mathematics.

“It’s not the lonely scientist-on-top entrepreneur model.”

The scientists cobbled together some staggering data in their review for Nature journal:

•  The last “state change” happened 12,000 years ago, at the end of the Ice Age – a 100,000-year era which came to an abrupt end in only one per cent of that time.
•  Humans have already converted 43 per cent of the planet for our use – through farming, industry and cities.
•  Depending on human population in 40 years, we will have dominated between 50 and 70 per cent of the planet.
• Simple systems only require a 58 per cent change before they reach their “tipping point.”

The findings come a month after the WWF’s 2012 annual Living Planet Report, released in May, which found that the Earth has lost nearly a third of its biodiversity in the last 40 years – and double that in the tropics.

That report ranked Canadians’ ecological footprint – each person’s planetary impact – as the eighth-worst per capita in the world, and five times larger than the poorest nations’. And while the forecast is grim, it’s not too late to act, Price said.

“People say, ‘This is all so unfortunate for nature; I wish it weren’t the case,’” he said. “But that’s only part of the question. Undermining our own life support system is the other half.

“Do we want to risk that? Obviously, the answer is no. . . Is our response enough? No. But are we paralyzed by that? We may feel that way, but the choices are all ours.”

Price agreed with the Nature study’s recommendation that more ecological monitoring is needed, alongside a dramatic reduction in carbon emissions and other environmental damage.

“We have to get off fossil fuels this generation,” he said.

“We all have to become more like accountants – how’s that for an odd recommendation? We need to learn to value – monetarily and otherwise – the ecological system’s services that we’re undermining.”

But such an accounting seems far off – particularly in light of recent federal budget cuts to environmental monitoring and scientific research.

“It’s a conundrum for all of us,” Price admits. “There appears to be less federal interest in the environment at a time when many are saying the situation is dire and needs to be addressed.

“Most of the progress in Canada and many places in the developed world have been at the state, provincial and municipal level. . . We are advocating the development of renewable energy sources, but we need a federal energy strategy that gets us from here to there.”

With the federal government unlikely to endorse the study’s findings, or its policy recommendations, what are the implications?

“These are serious problems, and we need to do serious research,” Mooers said. “The facts are clear. The best thing to come from this would be for governments to say, ‘We need to study this and invest heavily in this question, to see if it’s right or not. Can we get early warning signals?”

And if that doesn’t happen?

“These feel like dark days, that is for certain,” he says.