If it is coming to an end, let AZ be ground zero because I want no part, in being responsible for rebuilding mankind.

Please tell me, just how would we become extinct in 500 years? We are talking about the most adaptive animal that ever has lived on this planet. 1517 was a short time ago. — ssu

We have a much greater impact on our own environment. At earlier times this feedback was much weaker. In addition to exhausting easily extractable resources (which has happened before, albeit locally), we can now easily trigger a mass extinction event on the global scale.

Please tell me, just how would we become extinct in 500 years? — ssu

"The world" will not literally come to an end, unless a black hole stops by and vacuums it up before moving on to more pressing business. Homo sapiens will (probably) not literally vanish in 500 years, unless aliens stop by to rid the universe of whatever threat we pose to their own schemes. Eliot was writing poetry not prognostication, and I am not an extinction enthusiast.

However, we can speculate on how our species might meet its demise. It's a worthwhile exercise because we want to avoid coming close to extinction, let alone finding out what extinction feels like.

My guess is that we could at least come close to extinction through a combination of disasters, which are from "fairly" to "remotely" possible. All of them happening at once or in a maximally destructive sequence is not likely.

Disaster #1: A 'limited nuclear exchange' and the resultant firestorms cause a dramatic increase in CO2 and other greenhouse gases in the atmosphere.

Disaster #2: Global warming becomes quite severe over the next several centuries, and a very large percentage of humans die, owing to starvation and familiar diseases.

Disaster #3: Novel viruses and/or bacteria arise and kill off a significant portion of the humans who managed to survive severe global warming.

Disaster #4: A meteorite large enough to cause large-scale damage further depletes the remaining (small number of) humans. Or, the volcanic eruption of the Yellowstone Caldera would cause the same kind of damage as a meteorite impact.

The least imaginative apocalyptic fiction call for annihilation by means of multiple, well-timed disasters. We escape to the vicinity of Alpha Centauri and continue along our merry way.

What is quite possible are disasters # 2 and # 3, and we don't escape at all. In the worst-possible global warming scenarios, feedback loops accelerate the rate of warming. Some predictions say that by the end of this century, day-time temperatures may be too high for people to work outside for extended periods (like they do in agriculture, for instance) in areas of the world that are normally hot. In subsequent centuries, the zones of 'too damn hot' will cover presently temperate areas.

Even a moderately slow rate of global warming will be too fast for environments to adapt, and many species of plants and animals will fail.

Humans probably won't die of heat exhaustion; we are more likely to die from starvation, because food production will become difficult long before 500 years is up. A starving population will fall prey to ordinary illnesses. (One can safely assume that scientific capabilities will be diminished as people die off.)

What might bring us to our needs during a period of exhaustion and starvation is a novel disease. I have no idea what that disease might be, but in the last half century several new diseases have appeared (AIDS and Ebola) or appeared in new areas (West Nile Virus and the Zeka virus). Some bacteria have become, or are rapidly becoming, immune to antibiotics.

A limited nuclear war is a real possibility. "Limited" meaning... don't know. 100 to 500 nuclear explosions in a desert would probably not result in a rapid increase in death rates over the long run. Nuclear war, however, will not result in many desert test site explosions. Most of them will occur where there are large numbers of people and structures. Those explosions would be 'dirtier' both in terms of radiation and CO2 production.

Peak Oil is the perfect example of this: what basically has happened is Peak conventional Oil. As the price has gone up, so has the means to make oil from various materials. People simply forget two important things in the equation: the price mechanism and the advances in technology. — ssu

The limiting factor on oil production (which produces peak oil) is that at some point, the energy required to extract oil exceeds the energy available in the oil. When we reach that point, we're finished with that technology. There is literally no point in continuing.

Why the need for a bang or for a whimper? Why not voyage on without knowing? Not well, but forward none the less? — Noble Dust

Or, in the darker spirit:

Ever tried. Ever failed. No matter. Try Again. Fail again. Fail better. — Beckett

I have the impression that sci-fi predictions or depictions of the future have almost always overshot the mark in a lot of ways (flying cars, usually with no discernible means of flight or propulsion, are a staple of sci-fi depictions of "the future"). The TV show Lost in Space took place in 1997, for example.

Sometimes sci-fi has underestimated certain technological developments. For instance, the film Blade Runner had Atari signs in the background, and phone booths were still in use, with no sign of cell phones. — Arkady

Actually, 19th Century Sci-Fi did many times underestimate the technological advances. All that what now has become Steampunk. Naturally extremely rarely can people have an idea of some new technology and the way it's used before it's discovered.

The simple reason why even most serious sci-fi predictions overshot was because of simple extrapolation. Assume your living in the 1960's. Then 50 years ago humans had only the most rudimentary flying contraptions and during that decade there was a race to the moon. If you just simply extrapolate onward 50 years the same kind of progress then yes, the "overshooting" is quite reasonable. In the 1960's there's no idea (or the idea isn't popular) that natural resources would be the problem. After all, all the minerals we need are there in the asteroid belt.

Techonlogy advances rapidly at start, then stagnates and finally gets to a threshold that there basically isn't much way to improve it. Just look around your own home a look at what there is that would be there totally in the similar form (if not in design) in the 1960's. You likely have a stapler, a pencil, books, a lamp, chairs, which were reality in the 60's too. Even the fridge and the oven aren't so different.

What is telling of our time is that pessimism has taken over the Sci-Fi genre. That's the more popular view. People don't simply believe that things would be better in the future. Everything will be worse. After all, some here seem to believe that we as a species are extinct in a mere 500 years from now.

The limiting factor on oil production (which produces peak oil) is that at some point, the energy required to extract oil exceeds the energy available in the oil. When we reach that point, we're finished with that technology. There is literally no point in continuing. — Bitter Crank

First, Hubbert's theory of Peak Oil was about the production in general.

Second, we surely haven't reach that point and likely never, ever will. Remember the ever important link here to the price mechanism that demand and supply have.

We are likely finished with the technology simply when some other form of energy production is simple far more cheaper . That's when oil falls out of favour as a source of energy production. (We shouldn't forget other things that we get from it like plastics etc.)

The real point is that Hubbert was correct assuming that the technology would not have changed. Because this is what US oil production and Hubbert's Peak Oil thesis looks like now:



That is why one speaks of Peak Conventional Oil now. The above graph is one of the best graphs showing what effect technology can have as Hubbert's forcast would have proven otherwise correct without the advances in hydraulic fracturing and horizontal drilling. That hydraulic fracturing technology was invented in the 1940's and licenced in the 1950's, but naturally could compete with the low oil prices of the era, btw.

I heard someone mention that if all of today's nuclear bombs would explode now on the same place the explosion might correspond to an earthquake of a magnitude of 9 on the Richter scale. That's a big earthquake, but the world wouldn't end. The atmosphere might get polluted for a while, and parts of the oceans, but the world wouldn't end.

If the world ever ends, it might require the converse of the Big Bang, say, a cosmological implosion, a Big Slurp.

A planet presently called earth will survive the expansion of the sun (as it ages towards senescence) and then its contraction. What will be left of the planet will be a burnt sphere. So, no, "the world" or "the earth" will not be destroyed. Never, for all practical purposes. That doesn't mean anything alive, or once alive, will survive along with it.

I think it's safe to say that, oh, maybe 20,000 air bursts would generate enough widely distributed radiation and dust to cause some pretty seriously problems for the biosphere.

Your interpretation is more optimistic than mine.

No, we haven't reached the end of oil, yet. But it seems to me to be very overly optimistic to assume that oil production will continue indefinitely into the future, regardless of the energy or cash value of the oil extracted compared to the energy cost required to obtain the oil.

Can we get alone without oil? Sure we can, IF we are prepared (at some point in the not too distant future) to arrange our lives for a world where only very expensive unprocessed petroleum remains.

The most problematic scenario is the one in which we don't make timely and sufficient adaptations to other energy sources, like wind and solar. As James H. Kunstler points out, we don't have a substitute for cheap oil in the manufacture, distribution, and maintenance of windmills and solar arrays.

But it seems to me to be very overly optimistic to assume that oil production will continue indefinitely into the future, regardless of the energy or cash value of the oil extracted compared to the energy cost required to obtain the oil. — Bitter Crank

As I've said, how we get out from using oil is when there is a cheaper method of producing energy. Or to say it another way: when oil is so expensive to other means. Yet in the equation there simply has to be the other ways of producing energy. Because if the price of oil rises... and would still be the cheapest energy source, then you have a Giffen good.

The most problematic scenario is the one in which we don't make timely and sufficient adaptations to other energy sources, like wind and solar. As James H. Kunstler points out, we don't have a substitute for cheap oil in the manufacture, distribution, and maintenance of windmills and solar arrays. — Bitter Crank

..or we don't yet have electric passenger jets, cargo ships or electric heavy haul trucks, even if you start having electric cars. The combustion engine still rules, even if times are changing...

Yet the likely outcome for not having adequate energy or simply very expensive energy is obvious: there is far lower growth or simply stagnation. We've already seen what extremely high oil price does: it creates food riots in poor countries. Basically it's a handbrake on economic growth.

And that share of fossil fuels is still quite awesome, even if that share of renewable energy has been increasing:



Hence the idea that we'll just preserve, stop using energy, and likely the outcome is a self-inflicted economic depression, which brings social upheaval and political crises and in the end wars.

"The world" will not literally come to an end, unless a black hole stops by and vacuums it up before moving on to more pressing business. Homo sapiens will (probably) not literally vanish in 500 years, unless aliens stop by to rid the universe of whatever threat we pose to their own schemes. — Bitter Crank

So then the question is, how much we could backtrack, stagnate in 500 years?

The only time we remember this really happening is when Antiquity turned into the "Dark Ages" with a globalized economy which was very specialized halting in it's tracks and becoming far local and less advanced and specialized. Then you could see technology going backwards.

That doesn't mean anything alive, or once alive, will survive along with it.

I think it's safe to say that, oh, maybe 20,000 air bursts would generate enough widely distributed radiation and dust to cause some pretty seriously problems for the biosphere. — Bitter Crank

So if 'the world' doesn't refer to the world but biological life in the world, then the idea of a decisive end to it is still dubious, because if life is possible here, then it is possible elsewhere in millions or billions of planets that orbit suns under the same or similar conditions. It is improbable that all of their biospheres would get polluted at the same time and forever.

I don't think I suggested that intelligent life in the cosmos was going to get wiped out -- just here.

there is a theory, btw, that the reason we haven't encountered intelligent life from elsewhere in the galaxy (or more likely, just from our arm of the galaxy) is that civilizations all eventually run into a common problem of resource exhaustion, ecological decay, and social breakdown. Such disasters prevent them from getting very far away from their home planets.

I don't think I suggested that intelligent life in the cosmos was going to get wiped out -- just here. — Bitter Crank

The phrase "end of the world" seemed to refer to something more fundamental than the end of intelligent life here.

The assumption of a perpetually life-sustaining local environment seems improbable anyway. But organisms adapt, and by the time our sun burns out we might have already moved to an artificial planet, or space ships heading towards other habitable planets. Likewise, it does not seem improbable that intelligent life on other planets have already found ways to adapt to a universe in which suns burn out.