17 replies to this topic

[Persia]

It is 65m years since an asteroid is believed to have wiped out the dinosaurs, along with three-quarters of the species in existence at the time. Now, some scientists believe we are in the middle of another period of mass extinction and this time it could include us.

http://www.ft.com/cm...l#axzz1ejfPQ9ko

[ProfessorWhat]

Persia, on 25 November 2011 - 04:34 PM, said:

It is 65m years since an asteroid is believed to have wiped out the dinosaurs, along with three-quarters of the species in existence at the time. Now, some scientists believe we are in the middle of another period of mass extinction and this time it could include us.

http://www.ft.com/cm...l#axzz1ejfPQ9ko

Next time you should just c'n'p the article, I shouldn't have to join some other damn site just to read a story you could have posted here with links & credits

[Wickian]

For some reason I'm hesitant to accept that a species with a growing population is threatened.  If 3/4 of our population suddenly died we would still be in the billions.

[Br Cornelius]

Wickian, on 26 November 2011 - 08:56 PM, said:

For some reason I'm hesitant to accept that a species with a growing population is threatened.  If 3/4 of our population suddenly died we would still be in the billions.

You should do a bit of research into population dynamics. Once a species outstrips its resource base the collapse in population can be just as spectacular as the exponential rise. What is left is a few of the very hardiest individuals who basically live by recycling the nutrients of their deceased colleges. The nature of exponential population increase is such that you never see the wall coming until you have hit it, since each doubling comes faster and faster and causes more resource depletion in shorter intervals. You could be a decade away from total collapse and never spot it by looking at your current situation.

Fundamentally no species, not even man, escapes the immutable laws of nature. Our cleverness has simply postponed the inevitable collapse and made its eventual profile much more grim.

Of course there is another model of population dynamics - which is that of steady state - but we abandoned that so long ago that we can only dream of a long and prosperous future as far as the eye can see.

Br Cornelius

Edited by Br Cornelius, 26 November 2011 - 09:09 PM.

[Doug1o29]

Br Cornelius, on 26 November 2011 - 09:08 PM, said:

Fundamentally no species, not even man, escapes the immutable laws of nature. Our cleverness has simply postponed the inevitable collapse and made its eventual profile much more grim.

Br Cornelius

We are following a logistic growth curve (sort of).  Population is already declining in some countries and is expected to do so in more.  The world should reach net ZPG by the end of the century.

However:  there will be a lot of environmental degrade in the meantime.  In order to feed all those people we will need to clear and farm a lot of marginal land - land that cannot be farmed without damaging it.  And that will mean less food and starvation.  The same applies to other resources.

In order to make a human extinction event plausible, a mechanism is needed.  What mechanisms are there that could do this?  A large meteor impact?  Maybe Apophis on April 13, 2036?  Would that be big enough to cause human extinction?  Maybe one we haven't discovered yet?

Nuclear war, of course.  Putin is doing some saber rattling.  India and Pakistan continue their squabble - but nuclear weapons in a battle for Kashmir?  They'd destroy the very thing they're fighting over.  Nuclear winter would be the mechanism.  100 megatons would be enough if it were distributed in the right way.

Disease?  Possible, but not likely.  As the population dies off, the infection chain breaks, isolating remnant populations.  Some of these escape the epidemic and repopulate the earth.  Bird flue seems like the most immediate threat, but it is still several years away.  The Spanish flue only killed about 10% of us, so bird flue would have to be really nasty to kill 50%.  The last epidemic to reduce the earth's population was the Black Death - 700 years ago.  Traditionally, it was the plague, but Marburg or Korean hemhoragic (sp?) fever seem more likely.  We've already had a Marburg outbreak inside the Beltway - maybe that's a way to cure Congress.

Global warming will cause a lot of disruption, but human extinction doesn't seem to be in the cards.  But there is one mechanism by which it might happen:  If the melt-off of the Arctic ice cap eventually reduces the difference between polar and equatorial ocean temps enough to shut down the Gulf Stream, the result will be oceanic stagnation and a build-up of CO2 and methane in the ocean deeps.  If a major disturbance disrupts things (like a metor impact), the result could be an overturn of the oceans and poisoning of the atmosphere.  As I recall, five of the six largest extinction events occurred by this process.  But it will take hundreds of years for gas levels to build up that much:  we'll see it coming centuries before it gets here - in time to do something about it, if we choose to.

At this time, I would see extinction as unlikely.  Severe environmental degrade though, seems unstoppable.  For the world's people as a whole, the foreseeable future is not going to be better than the present.
Doug

[Bavarian Raven]

Quote

In order to make a human extinction event plausible, a mechanism is needed. What mechanisms are there that could do this? A large meteor impact? Maybe Apophis on April 13, 2036? Would that be big enough to cause human extinction? Maybe one we haven't discovered yet?

Nuclear war, of course. Putin is doing some saber rattling. India and Pakistan continue their squabble - but nuclear weapons in a battle for Kashmir? They'd destroy the very thing they're fighting over. Nuclear winter would be the mechanism. 100 megatons would be enough if it were distributed in the right way.

take more then a nuclear war/nuclear winter to destroy humanity imho.

Quote

Disease? Possible, but not likely. As the population dies off, the infection chain breaks, isolating remnant populations. Some of these escape the epidemic and repopulate the earth. Bird flue seems like the most immediate threat, but it is still several years away. The Spanish flue only killed about 10% of us, so bird flue would have to be really nasty to kill 50%. The last epidemic to reduce the earth's population was the Black Death - 700 years ago. Traditionally, it was the plague, but Marburg or Korean hemhoragic (sp?) fever seem more likely. We've already had a Marburg outbreak inside the Beltway - maybe that's a way to cure Congress.

agreed.

Quote

Global warming will cause a lot of disruption, but human extinction doesn't seem to be in the cards. But there is one mechanism by which it might happen: If the melt-off of the Arctic ice cap eventually reduces the difference between polar and equatorial ocean temps enough to shut down the Gulf Stream, the result will be oceanic stagnation and a build-up of CO2 and methane in the ocean deeps. If a major disturbance disrupts things (like a metor impact), the result could be an overturn of the oceans and poisoning of the atmosphere. As I recall, five of the six largest extinction events occurred by this process. But it will take hundreds of years for gas levels to build up that much: we'll see it coming centuries before it gets here - in time to do something about it, if we choose to.

agreed - and we (as a species) could survive even an asteroid impact akin to the one that destroyed the dinos. sure, hundreds of millions would die in the resulting 'nuclear winter' (i dont like that term, but its the only one i have). but humanity would survive and maybe even be better for it.  

Quote

At this time, I would see extinction as unlikely. Severe environmental degrade though, seems unstoppable. For the world's people as a whole, the foreseeable future is not going to be better than the present.
Doug

ya...the future sure doesnt look friendly... does it  
sooner or later though, the population will fall to a sustainable level    how that level will be achieved is still up for debate though  

[Doug1o29]

Bavarian Raven, on 27 November 2011 - 02:26 AM, said:

take more then a nuclear war/nuclear winter to destroy humanity imho.

Depends on the war.  The world's arsenals have many times what is needed to do the job; it all depends on how the warheads are distributed.  And, I believe the US has a half-dozen or so cobalt bombs, stored at Los Alamos, last I knew.  Wouldn't be surprised to hear that some other countries have cobalt bombs, too.

Try "impact winter."

We're forgetting "volcanic winter."  There might be a super-volcano around that could do it - not likely, but Toba ALMOST exterminated us once.  Someday it's coming back for a rematch.  A magma plume might be able to do it, but if there's one around, we don'ty know about it - yet.

Any other ideas?
Doug

[Wickian]

Br Cornelius, on 26 November 2011 - 09:08 PM, said:

You should do a bit of research into population dynamics. Once a species outstrips its resource base the collapse in population can be just as spectacular as the exponential rise. What is left is a few of the very hardiest individuals who basically live by recycling the nutrients of their deceased colleges. The nature of exponential population increase is such that you never see the wall coming until you have hit it, since each doubling comes faster and faster and causes more resource depletion in shorter intervals. You could be a decade away from total collapse and never spot it by looking at your current situation.

Fundamentally no species, not even man, escapes the immutable laws of nature. Our cleverness has simply postponed the inevitable collapse and made its eventual profile much more grim.

Of course there is another model of population dynamics - which is that of steady state - but we abandoned that so long ago that we can only dream of a long and prosperous future as far as the eye can see.

Br Cornelius

We will eventually go extinct true, but that isn't going to happen unless the planet becomes inhospitable to land-based mammals.  

Starvation won't do it, war won't do it, an ice-age won't do it, a world-wide super-virus might be plausible(I somehow doubt it though).

[Br Cornelius]

Wickian, on 27 November 2011 - 07:11 AM, said:

We will eventually go extinct true, but that isn't going to happen unless the planet becomes inhospitable to land-based mammals.  

Starvation won't do it, war won't do it, an ice-age won't do it, a world-wide super-virus might be plausible(I somehow doubt it though).

A collapse of over 90% of our population is not extinction - but is almost  inevitable given our current behaviour. Its all about resource depletion and the two greatest threats are soil erosion and not enough potable water. Peak oil - which has either already happened or will happen in the next decade - will make our culture even more disfunctional, and will mainly cause starvation and war.

Br Cornelius

[Wickian]

Br Cornelius, on 27 November 2011 - 08:18 AM, said:

A collapse of over 90% of our population is not extinction - but is almost  inevitable given our current behaviour.

I disagree.  If push comes to shove every piece of viable land on this planet will be converted into farmland or housing and any remaining wildlife either put into zoos or farms.

Quote

Its all about resource depletion and the two greatest threats are soil erosion and not enough potable water. Peak oil - which has either already happened or will happen in the next decade - will make our culture even more disfunctional, and will mainly cause starvation and war.

Br Cornelius

Those are definitely concerns, but as long as natural disasters don't happen, they're nothing our society can't handle.  Farmland can be maintained(again, barring natural disasters) to prevent soil erosion from becoming a real threat.  Some parts of the world already suffer from water shortages and droughts and it hasn't impacted the advancement of our technology or civilization yet.  If anything it's improved it a bit with the creation of various water filtration technologies.

Running out of oil without a real alternative fuel or new engine is our primary concern right now.  We'll still have electricity(coal, solar, wind, and water generators) so our civilization won't completely collapse I don't think.

The timeline I've read has varied from 10 to 50 or more years before it happens, but we should be prepared beforehand.

[libstaK]

I kinda think at some point it's bound to happen, for one reason or another.  If you look at evolution over millions of years, the species that dominated always slide into obscurity if not extinction eventually.  Pretty arrogant to think we can escape that imo.

[Bester]

Wickian, on 27 November 2011 - 09:19 AM, said:

Running out of oil without a real alternative fuel or new engine is our primary concern right now.  We'll still have electricity(coal, solar, wind, and water generators) so our civilization won't completely collapse I don't think.

The timeline I've read has varied from 10 to 50 or more years before it happens, but we should be prepared beforehand.

If this priority interests you, you might want to look into the Transition Movement, which is a loosely affiliated worldwide effort to prepare for the many different effects that will result from declining availability of oil.

Transition US site

[Br Cornelius]

Wickian, on 27 November 2011 - 09:19 AM, said:

I disagree.  If push comes to shove every piece of viable land on this planet will be converted into farmland or housing and any remaining wildlife either put into zoos or farms.



Those are definitely concerns, but as long as natural disasters don't happen, they're nothing our society can't handle.  Farmland can be maintained(again, barring natural disasters) to prevent soil erosion from becoming a real threat.  Some parts of the world already suffer from water shortages and droughts and it hasn't impacted the advancement of our technology or civilization yet.  If anything it's improved it a bit with the creation of various water filtration technologies.

Running out of oil without a real alternative fuel or new engine is our primary concern right now.  We'll still have electricity(coal, solar, wind, and water generators) so our civilization won't completely collapse I don't think.

The timeline I've read has varied from 10 to 50 or more years before it happens, but we should be prepared beforehand.

Current agriculture is almost totally dependent on cheap oil, since peak oil has either happened (highly probable) or about to happen - agricultural output has also already peaked and can only decline. There is no way to substitute for the fertilizers we currently use without cheap oil. Since population will still climb for another 30yrs or more - there is going to be an inevitable shortfall. Starvation - leading to war.

Pressing into service all land for agriculture will not solve the oil bottleneck. Land which is currently been used for agriculture is currently been lost to desertification and erosion at about a million acres a year. All marginal lands have very short productivity periods because they are intrinsically nutrient poor - and without plentiful cheap oil - they will burn out in a decade or so. this is what happens on all marginal land pressed into agriculture.

This is also not considering the multiple "services" which wild habitats provide to humanity - from air cleaning to water recycling to intrinsic diversity which is the foundation of the ecological health. if we push the marginal lands to extinction the network of life which supports us will collapse, and in some unexpected way will deliver a blow to our sustainability.

I am not personally a techno-optimist, since all technology has always proved itself to be a double edged sword delivering benefits and penalties in equal measure.

We either learn to live in balance with our ecosystem or it will kill us - it really is that simple and there are numerous precedents in nature and history for the consequences of failing to learn that lesson. We are part of a system and believing that we can press gang all systemic resources to bail us out of the mess we have created is just delusional and will not work. My guess it is already to late to do anything about this, but certainly unless we radically change our priorities and ways of life it will be locked in within the next decade or so.

Br Cornelius

[Doug1o29]

Br Cornelius, on 27 November 2011 - 08:18 AM, said:

A collapse of over 90% of our population is not extinction - but is almost  inevitable given our current behaviour. Its all about resource depletion and the two greatest threats are soil erosion and not enough potable water. Peak oil - which has either already happened or will happen in the next decade - will make our culture even more disfunctional, and will mainly cause starvation and war.

Br Cornelius

Where did that 90% figure cpme from?  That's pretty pessimistic.

Peak oil has already happened - in the 1970s.
Doug

[Doug1o29]

Wickian, on 27 November 2011 - 09:19 AM, said:

Farmland can be maintained(again, barring natural disasters) to prevent soil erosion from becoming a real threat.

Marginal land is already being farmed and degraded in the process.  As soils degrade, we must either clear more land, or cut production (See:  soil loss tolerance.).

Quote

Some parts of the world already suffer from water shortages and droughts and it hasn't impacted the advancement of our technology or civilization yet.  If anything it's improved it a bit with the creation of various water filtration technologies.

T. Boone's attempt at stealing water from the Ogalala has failed, at least for now.  Water shortages are just beginning.  Both the Ogalala and the Snake River Aquifers are being depleted, but have yet to run out.  Water desalinization is an energy-intensive way to purify water.  Some cities have built plants, but the water costs more.  Like everything else, there's always going to be enough if you have the money to take it away from those who are less fortunate.

Quote

Running out of oil without a real alternative fuel or new engine is our primary concern right now.  We'll still have electricity(coal, solar, wind, and water generators) so our civilization won't completely collapse I don't think.

The alternate energy source in the US is natural gas.  The companies are drilling like mad.  We've had three new gas wells go in within site of town within the last two months.  There's a lot of money to be made here if you have a technical background.

Coal is dirty and their ads don't change that.  Not to mention the practice of cutting the tops off mountains to get at coal seams.  I used to live in Madisonville, Kentucky.  I've seen up close and personal how they treat the land and landowners.  Just south of town was a newly reclaimed site with ponds and trees and a big sign proclaiming "This area reclaimed by Peabody Coal."  Across the road was an orphan spoil.  I think it should have a sign saying "This area not reclaimed by Peabody Coal."  John Denver had it right.

Water power is at its peak right now.  There are no more good sites for dams.  We have retrofitted most existing dams with penstocks and generators.  Larger populations will need other power sources.

We are building wind farms at a great pace, but not fast enough to keep up with rising demand.  Wind will be hard-put just to keep its current market share.

There's a lot of untapped potential in passive solar.  Not big, expensive programs, but little things by millions of people, each making a small difference, but collectively having a huge impact.

Quote

The timeline I've read has varied from 10 to 50 or more years before it happens, but we should be prepared beforehand.

Depends on which disaster gets us first.  The problems get bad when several hit at the same time.
Doug