Are Humans Doomed to Extinction?

Canada and the World

Current Events with a Canadian Perspective

Last update

19 November 2010

Are Humans Doomed to Extinction?

Some think we’re on a path of self destruction,

while others think we’ll disappear as a species

simply in the natural course of events

Thomas Homer-Dixon is Director of the Trudeau Centre for Peace and Conflict Studies. He thinks real trouble lies ahead and has written about this in The Upside of Down: Catastrophe, Creativity, and the Renewal of Civilization.

“Many people suffer,” he writes, “because without complex institutions, technologies, and social roles, societies can’t keep large populations living well. After collapse, people consume far less, move around far less, communicate far less, and die far sooner.”

Causes of Social Collapse

On the question of what might cause our complex society to collapse, he agrees with those who believe societies in general fall as a result of the “convergence of multiple stresses,” such as rapid population growth, scarcity of key resources, and a financial crisis.

He explains in a Globe and Mail article (May 2006) that in the last half century “largely because of the enormous growth and relentless integration of the world’s economy, humankind and the natural environment it exploits have evolved into a single socio-economic system that encompasses the planet. As a result, a financial crisis, a terrorist attack, or a disease outbreak can now have almost instantaneous destabilizing effects from one side of the world to the other.”

Nevertheless, Professor Homer-Dixon ends on a positive note. He believes most of us “who are non-extremists” can work together for a better future.

Human Impact on Environment

Meanwhile, Alan Weisman, author of The World Without Us, says the human race has no right to expect that our species is somehow guaranteed to survive forever.

In his 2007 book he shows the damage we’ve done: it would take about 35,000 years, for example, for lead from smokestacks to be cleansed from the soil, and at least 100,000 years for carbon dioxide to return to pre-human levels.

Toxic man-made chemicals such as polychlorinated biphenyls and dioxins would probably still be here seven million years after our demise, and the half-million tonnes of depleted uranium-238 in the U.S. would reach its half-life in 4.5 billion years.

But, the author also shows how quickly Nature would reclaim the Earth if we weren’t here to exploit it. Water seeps in. Buildings crumble. Swimming pools become planter boxes. Birds and animals flourish. Fields and suburbs become forests.

A New Scientist article (October 2006) notes that, in just a few thousand years humans “have swallowed up more than a third of the planet’s land for our cities, farmland, and pastures. By some estimates, we now commandeer 40 percent of all its productivity. And we’re leaving quite a mess behind: ploughed-up prairies, razed forests, drained aquifers, nuclear waste, chemical pollution, invasive species, mass extinctions, and now the looming spectre of climate change. If they could, the other species we share Earth with would surely vote us off the planet.”

Do Humans only Have a Century Left?

Professor Peter Barrett is Director of Victoria University’s Antarctic Research Centre in New Zealand. He warns that extinction of humankind and human society as we know it may come about within 100 years.

He thinks we’ll succumb to impending climate change and ecological catastrophe, unless we can dramatically reduce greenhouse gas emissions. Otherwise, he says temperatures will return our climate to where it was before humans existed and the global sea level was 70 metres higher.

“Much greater effort is needed to reduce CO2 levels, to lessen stresses on global ecosystems and avoid the collapse of civilization as we know it by the end of this century,” he writes (Pacific Ecologist, Summer 2005).

Professor Barrett’s predictions are based on reports by the Intergovernmental Panel on Climate Change, a group of 1,000 scientists from 100 nations.

Optimistic Future is Possible

A 1999 Lifeboat Foundation report looks on the bright side.

The paper, Risking Human Extinction, suggests that “despite all such dangers…humans may well have a good chance (perhaps as high as 70 percent) of surviving the next five centuries.”

And, if that happens, the report’s author, John Leslie, says those of us alive now “could easily be among the earliest 0.001 percent of all humans who will ever have lived.”

However, he adds, our long-term future remains uncertain.

With more than 15,000 species threatened with extinction, some think it’s nothing more than human arrogance that makes us think we’re immortal as a species. They say there’s little doubt that we’ll die out too.

According to Reinhard Stindl, at the Institute of Medical Biology in Vienna, our demise could lie at the tips of our chromosomes.

In a controversial new theory he suggests that all eukaryotic species (everything except bacteria and algae) have an evolutionary “clock” that ticks through generations, counting down to an eventual extinction date.

According to a Guardian article in 2004, “This clock might help to explain some of the more puzzling aspects of evolution, but it also overturns current thinking and even questions the orthodoxy of Darwin’s natural selection.

“For over 100 years, scientists have grappled with the cause of ‘background’ extinction. Mass extinction events, like the wiping out of dinosaurs 65 million years ago, are impressive and dramatic, but account for only around four percent of now extinct species. The majority slip away quietly and without any fanfare. Over 99 percent of all the species that ever lived on Earth have already passed on.”

Sources

“Prepare Today for Tomorrow’s Breakdown.” Thomas Homer-Dixon, Globe and Mail, May 14, 2006.

“Imagine Earth without People.” Bob Holmes, New Scientist, October 12, 2006.

“Will Unchecked Global Warming Destroy Civilization by Century’s End?” Peter Barrett, Pacific Ecologist, Issue 11

“Do Humans Face Certain Extinction?” Kate Ravilious, The Guardian, April 22, 2004.

© Canada and the World, October 2007

All Rights Reserved

Digging through the layers of rock, paleontologists have found that evolution seems to go in fits and starts. Most species seem to have long, stable periods followed by a burst of change, not the slow, steady process pre-dicted by natural selection.

Describing human population growth as an “inexorable horror,” Voluntary Human Extinction Movement founder Les Knight has said, “It’s obvious that the intentional creation of another [human being] by anyone anywhere can’t be justified today,” according to a San Francisco Chronicle report.

“The hopeful alternative to the extinction of millions of species of plants and animals is the voluntary extinction of one species: Homo sapiens... us,” Knight says. “Each time another one of us decides to not add another one of us to the burgeoning billions already squatting on this ravaged planet, another ray of hope shines through the gloom.”

Alternatively, author Alan Weisman points out that if every human female on Earth now gave birth to only one child, the human population would be at about 1.6 billion by 2100, compared with nine billion by the middle of this century if reproduction rates continue at the current rate.

Professor Nick Bostrom (Faculty of Philosophy, Oxford University) presents a lengthy list of potential hazards to human existence in an article in The Journal of Evolution and Technology.

Extinctions in Earth’s History

New Scientists (Earth Faces Sixth Mass Extinction)

Thomas Homer-Dixon, says episodes of crisis or breakdown are not always a bad thing: they can motivate us to improve.

He says keeping breakdown from becoming catastrophic means “making our technologies, economies, and communities more resilient.

“For instance, we can increase the ability of cities, towns, and even households to produce essential goods and services, such as energy and food, instead of depending completely on distant producers of these things for our day-to-day survival – as we do now.”