This post's title poses what used to be called the $64,000 question—will Homo sapiens still roam the Earth a century or two hence? Now it is the $64,000,000,000,000 question.
To get the ball rolling, let's start with the views expressed by microbiologist Frank Fenner, who did an interview with the Australian in 2010. Here's some background on Fenner, who was 95 years old when he did the interview. There is more background information in the article.
Fenner is an authority on extinction. The emeritus professor in microbiology at the Australian National University played a leading role in sending one species into oblivion: the variola virus that causes smallpox.
And his work on the myxoma virus suppressed wild rabbit populations on farming land in southeastern Australia in the early 1950s.
He made the comments in an interview at his home in a leafy Canberra suburb. Now 95, he rarely gives interviews. But until recently he went into work each day at the ANU's John Curtin School of Medical Research, of which he was director from 1967 to 1973.
Here is Fenner's view of the human situation in the 21st century.
He says the Earth has entered the Anthropocene. Although it is not an official epoch on the geological timescale, the Anthropocene is entering scientific terminology. It spans the time since industrialisation, when our species started to rival ice ages and comet impacts in driving the climate on a planetary scale.
Fenner says the real trouble is the population explosion and "unbridled consumption".
The number of Homo sapiens is projected to exceed 6.9 billion this year, according to the UN. With delays in firm action on cutting greenhouse gas emissions, Fenner is pessimistic.
[My note: we passed the 7 billion mark last year.]
"We'll undergo the same fate as the people on Easter Island," he says. "Climate change is just at the very beginning. But we're seeing remarkable changes in the weather already.
"The Aborigines showed that without science and the production of carbon dioxide and global warming, they could survive for 40,000 or 50,000 years. But the world can't. The human species is likely to go the same way as many of the species that we've seen disappear.
"Homo sapiens will become extinct, perhaps within 100 years," he says. "A lot of other animals will, too. It's an irreversible situation. I think it's too late. I try not to express that because people are trying to do something, but they keep putting it off.
"Mitigation would slow things down a bit, but there are too many people here already."
It's an opinion shared by some scientists but drowned out by the row between climate change sceptics and believers.
I should note that this last point—the problems attending growth being drowned out by a bogus debate about the climate science—is essential if you want to understand why the human species may become extinct in the next few hundred years. This same behavior has been called fiddling while Rome burns, and humans seem to be especially adept at it.
Another limitation is covered by the expression not seeing the forest for the trees. That limitation also has a time dimension—characteristic human myopia. We can immediately see that we have a consciousness problem here, not an intelligence problem. People must be able to see their world from the outside looking in, they must reflect on who they are and sort out their self-destructive behaviors. Generally speaking, the necessary separation is impossible for humans to achieve. People are typically totally immersed in the crazy world they themselves have created. They need to view the lunatic asylum from outside its walls.
Is our species headed for rapid extinction as Frank Fenner believes? On the face of it, this question is impossible to answer. It is a question about the distant future (on human timescales). For example, some resource scarcity people have bet that peak oil, peak coal and peak everything else will crush economic growth well before we put enough CO2-equivalent into the atmosphere to raise the Earth's surface temperature much over 2° C (centigrade). Is that a plausible scenario?
In some ways it is, but there are too many uncertainties. The crude oil supply is obviously precarious and will become more so over time. But what about coal? Really, no one knows how much economically exploitable coal lies out there waiting for humans to dig it up. And natural gas will likely be relatively abundant for some decades to come.
I prefer behavioral criteria in thinking about human outcomes. I guarantee you that if humans start running short of energy, they will burn every combustible thing in sight in order to cook their meals, heat or cool their homes, move goods or themselves from place A to place B, etc. That will obviously wreak all sorts of ecological havoc.
When we think about the much longer-term future, the number of possible scenarios quickly becomes unmanageable. The best we can do is identify destructive trends and extrapolate them based on our knowledge of ourselves (the human species). We know what our species does, and has always done, so naturally we expect them to do more of it in the future. In the Australian article, Stephen Boydon offered an alternative view which is not far removed from Fenner's.
Fenner's colleague and long-time friend Stephen Boyden, a retired professor at the ANU, says there is deep pessimism among some ecologists, but others are more optimistic.
"Frank may be right, but some of us still harbour the hope that there will come about an awareness of the situation and, as a result, the revolutionary changes necessary to achieve ecological sustainability," says Boyden, an immunologist who turned to human ecology later in his career.
"That's where Frank and I differ. We're both aware of the seriousness of the situation, but I don't accept that it's necessarily too late. While there's a glimmer of hope, it's worth working to solve the problem. We have the scientific knowledge to do it but we don't have the political will."
We don't have the political will. And that, ladies and gentlemen, is where the rubber hits the road. I don't see even a glimmer of hope because "political will" is a direct reflection of Human Nature. Lions hunt, fish swim and monkeys cavort through the trees. What humans do is very much more complex, but at the most fundamental level their behavior is fixed like that of all the other animals.
Well, I see I have successfully avoided the human extinction question! So here's a final thought: humans may not be wise, but they are technologically and socially clever. Cleverness is often conflated with wisdom, but they are quite obviously not the same thing. Humans are also astonishingly resilient.
Therefore I doubt the planet will be entirely human-free two centuries from now.
Bonus Video — an excellent example of human busy-ness inside their self-created nuthouse