Human evolution, say many scientists, was in part a product of major environmental shifts. Now, says a new study, the roles are reversed, and the impact will be far more radical.
Ice age Earth at glacial maximum
Scientists have often theorized that major environmental or climate shifts in prehistory had a profound impact on the course of human evolution and, by extrapolation, the course of the development of human civilization. They have pointed to archaeological and paleontological evidence to support their arguments. Now, based on a recently completed study, it appears that the relationship roles have been reversed. Mother Nature is likely the one now being acted upon for change, and the actor is human. Moreover, say researchers, that change, which they have coined as a "state shift" in the earth's global ecosystem, will occur comparatively quickly, leading to a "planetary collapse" of the world as we know it -- much like the state shift that occurred about 12,000 years ago that helped to transform humans from hunter-gatherers to urban dwellers and wielders of advanced technology. But the upcoming change may be far more radical, if the researchers are correct.
Using theoretical frameworks and data derived from ecosystem modeling and paleontological evidence, an international group of 18 scientists are predicting that humanity is facing a much worse collision course with Mother Nature than currently thought, and that it is relatively imminent. In the paper, currently published in the journal Nature, they are suggesting that the current global ecosystem is accelerating toward an irreversible collapse, and that it could occur within this century. They suggest that the Earth's accelerating loss of biodiversity, increasingly extreme fluctuations in climate, the growing interdependence of various ecosystems, and a quickly changing total "energy budget" all combine together to create a planetary threshold or tipping point to a profound shift in the global ecosystem/climatological balance as we know it today. The study points to "unprecedented rates and magnitudes of human population growth with attendant resource consumption, habitat transformation and fragmentation, energy production and consumption, and climate change" as the salient factors at the root of the changes.
"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" says Arne Mooers, a professor of biodiversity at Simon Fraser University and one of the study authors. "That's like going from a baby to an adult state in less than a year. Importantly, the planet is changing even faster now........The odds are very high that the next global state change will be extremely disruptive to our civilizations. Remember, we went from being hunter-gatherers to being moon-walkers during one of the most stable and benign periods in all of Earth's history."
Moreover, Mooers states that once this tipping point or threshold is reached and crossed, then we will be at the point of no return, an alarming prospect at any level.
"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."
The threshold is defined by a 50 percent transformation of the Earth's surface. More than 50 percent means that we are out of time for delay, and that a planetary collapse is then inevitable. Already, the Earth has seen a 43 percent transformation due to human activity that has converted the ancient landscapes into new agricultural and urban areas.
Their prescription for addressing the problem?
Says Mooers: "Society globally has to collectively decide that we need to drastically lower our population very quickly. More of us need to move to optimal areas at higher density and let parts of the planet recover. Folks like us have to be forced to be materially poorer, at least in the short term. We also need to invest a lot more in creating technologies to produce and distribute food without eating up more land and wild species. It's a very tall order."