Using scientific theories, toy ecosystem modeling and paleontological evidence as a crystal ball, 18 scientists, including one from Simon Fraser University, predict we're on a much worse collision course with Mother Nature than currently thought.
In Approaching a state-shift in Earth's biosphere, a paper just published in Nature, the authors, whose expertise span a multitude of disciplines, suggest our planet's ecosystems are careening towards an imminent, irreversible collapse.
Earth's accelerating loss of biodiversity, its climates' increasingly extreme fluctuations, its ecosystems' growing connectedness and its radically changing total energy budget are precursors to reaching a planetary state threshold or tipping point.
Once that happens, which the authors predict could be reached this century, the planet's ecosystems, as we know them, could irreversibly collapse in the proverbial blink of an eye.
"The last tipping point in Earth's history occurred about 12,000 years ago when the planet went from being in the age of glaciers, which previously lasted 100,000 years, to being in its current interglacial state. Once that tipping point was reached, the most extreme biological changes leading to our current state occurred within only 1,000 years. That's like going from a baby to an adult state in less than a year," explains Arne Mooers. "Importantly, the planet is changing even faster now."
The SFU professor of biodiversity is one of this paper's authors. He stresses, "The odds are very high that the next global state change will be extremely disruptive to our civilizations. Remember, we went from being hunter-gathers to being moon-walkers during one of the most stable and benign periods in all of Earth's history.
"Once a threshold-induced planetary state shift occurs, there's no going back. So, if a system switches to a new state because you've added lots of energy, even if you take out the new energy, it won't revert back to the old system. The planet doesn't have any memory of the old state."
These projections contradict the popularly held belief that the extent to which human-induced pressures, such as climate change, are destroying our planet is still debatable, and any collapse would be both gradual and centuries away.
This study concludes we better not exceed the 50 per cent mark of wholesale transformation of Earth's surface or we won't be able to delay, never mind avert, a planetary collapse.
We've already reached the 43 per cent mark through our conversion of landscapes into agricultural and urban areas, making Earth increasingly susceptible to an environmental epidemic.
"In a nutshell, humans have not done anything really important to stave off the worst because the social structures for doing something just aren't there," says Mooers. "My colleagues who study climate-induced changes through the earth's history are more than pretty worried. In fact, some are terrified."
|Contact: Carol Thorbes |
Simon Fraser University