Tyndall Center: The Radical Emission Reduction Conference

[TeaPotty]

Kevin Anderson and the Tyndall Center have an event soon:

The Radical Emission Reduction Conference
London, 10-11 December 2013

Conference Program

Conference Speakers' Abstracts



In the video, Kevin Anderson discusses how in a matter of 5 years of further inaction, we will be discussing avoiding 3°C-4°C temps.

James Hansen's new paper shows a 15% reduction rate if we delay decarbonization till 2020:
Assessing “Dangerous Climate Change”: Required Reduction of Carbon Emissions to Protect Young People, Future Generations and Nature

As discussed above, keeping global climate close to the Holocene range requires a long-term atmospheric CO2 level of about 350 ppm or less, with other climate forcings similar to today’s levels. If emissions reduction had begun in 2005, reduction at 3.5%/year would have achieved 350 ppm at 2100. Now the requirement is at least 6%/year. Delay of emissions reductions until 2020 requires a reduction rate of 15%/year to achieve 350 ppm in 2100. If we assume only 50 GtC reforestation, and begin emissions reduction in 2013, the required reduction rate becomes about 9%/year.

*gulp* 

[ritter]

*gulp* 

You can say that again! I don't see any way that this is achievable short of collapsing (further) the global economy. And where do we plant all of those trees?

[TeaPotty]

Kevin Anderson was also interviewed about the conference, and said:

"The next 5 years for the principle emitting countries of the world - in that I also include the 300 million people in China who live lives like those of us relatively wealthy ones within the EU - if the high-emitting people on the planet have not radically reduced emissions [within 5 year's time] we will have effectively locked ourselves into a high carbon future.

We will have locked the poor people around the planet, our own children and most other species into a future that will be somewhere between detrimental and disastrous. It's hard to know exactly how that's going to play out, but it's not a future you'd want to bequeath to your own children, let alone other people's children, let alone the planet itself.

 I think we're on that cusp. The rate of emissions growth is so rapid, if we don't come off that curve in 5 years from now, the emissions will be so high that we're talking about 3 to 4 degree type futures."

[www.youtube.com/watch?v=Tl7YF4fmh4o]

[TeaPotty]

Live Stream:

http://www.tyndall.ac.uk/communication/news-archive/2013/live-stream-radical-emissions-reduction-conference

[domen_]

Will there be video available?

[wili]

I posted this on the other thread, but here is the latest quote I've seen from Anderson:

To have a good chance at staying under two degrees C, industrialised countries need to crash their CO2 emissions 10 percent per year starting in 2014, said Kevin Anderson of the Tyndall Centre for Climate Change Research at the University of Manchester.

http://www.skepticalscience.com/South-Scores-11th-Hour-Win-on-Climate-Loss-and-Damage_IPS.html

(I can't even convince my otherwise-fairly-aware family to reconsider their compulsion to constantly take long-distance non-essential airplane trips whenever they can afford it...and sometimes when they can't.)

[TeaPotty]

Videos went up today (scroll down for links to the individual talks):

http://www.tyndall.ac.uk/communication/news-archive/2013/radical-emissions-reduction-conference-videos-now-online

[wili]

"The next 5 years for the principle emitting countries of the world - in that I also include the 300 million people in China who live lives like those of us relatively wealthy ones within the EU - if the high-emitting people on the planet have not radically reduced emissions [within 5 year's time] we will have effectively locked ourselves into a high carbon future

Does anyone see any possibility that the global richest 20% will drastically reduce their emissions in the next very few years?

Basically, these scientists are telling us in various ways that it is now game over. There is no conceivable way to prevent 'high carbon future,' meaning temperatures well above 2 degrees--probably more like 6 by the end of the century or so.

[domen_]

Carbon tax is the only thing that can peak emissions in next few years.

[wili]

I'm not against taxing it, but ultimately doesn't that fall pretty far short of what is actually required at this point?

We are essentially dropping bombs on the planet/future at a rate of 4 atom bombs a second.

If in WWII it had become known to the US gov that there was a factory in the US making bombs and sending them to the Germans or Japanese to be dropped on US citizens, would we have merely come up with a tax to discourage such unwanted activity?

[crandles]

You ban things rather than tax them out of existence. But I suggest that banning use of ff now would clearly be a cure that is worse than the disease - the economy would collapse now rather than much later even under severe rates of climate change. We want to reduce usage and work on technologies that would enable more radical reduction so that if it becomes necessary to stop further increases in CO2 levels it won't be quite that painful. In such a situation, economists seem to agree on putting a price on carbon to internalise the externalities. Carbon Tax seems simpler than Cap and trade.

Certainly Myles Allen thinks we are focusing far too much on subsidising windmills when we should be putting funding into CCS.

http://data.parliament.uk/writtenevidence/WrittenEvidence.svc/EvidenceHtml/4280

http://scienceblogs.com/stoat/2011/06/06/carbon-tax-now-1/

[wili]

Well, we can agree that Cap and Trade is not a great route, though I don't mind the "cap" side of it.

And I didn't say anything about an immediate ban. Rationing and a fairly rapid sequenced shut down of ff facilities, both mining and power plants, is more what I had in mind.

You speak with concern about the collapse of the economy. The economy is whatever we want to make it. We could have full employment tomorrow even with a shrinking economy if we wanted to do so. There are plenty of land restoration and ag jobs to be done, and the sooner we get people trained and practiced at doing them, the better. And most jobs can be cut to 30 hours work weeks, instantly creating lots more jobs to fill in the extra 10 hours.

What we can't adjust is a collapsing earth. Once the Arctic is melted, it's not coming back for a long, long time. And it is on its way out now, if you hadn't noticed. And a melted Arctic sets off/is setting off all sorts of other feedbacks that will not be kind.

We actually have exactly no time. And the longer we delay, the more it will be necessary to crash the economy to have any chance of a livable planet to leave for any future generations.

[JimD]

Crandles

From the various forms of BAU viewpoints (the coal companies like it because they will make lots more profits and the GreenBAU folks like it because it seems to grab the carbon and still allow the growth/progress fantasy to continue) CCS seems to have promise.  But I think if we look at our emissions situation from a systemic viewpoint we can come to the conclusion that the time for CCS to really help us is past and we need to work towards solutions which have a better chance of helping us.

Think about how many coal power plants there are in the world.  Most of these plants are very small and retrofitting them with CCS technology is pretty impractical.  Many more plants are very old and retrofitting them is out of the question financially.  Modern large plants or new plants could be retrofitted or built with CCS technology, but then we get into the first of the real killer issues.

Fuel requirements.  IF we converted all coal plants to CCS versions the demand for coal would jump as much as 40%.  CCS plants produce much less electricity per ton of coal than a standard plant.   It would make it tougher to shut down the very old and small plants as the need for extra power generation due to the losses from converting to CCS.  Sort of a Catch-22 situation.  The coal power and coal mining industries would love this situation.  A boom in business.  Growth. 

Another big issue with the CCS technology is that I have read we are a decade or more from having the technology all worked out.  Another idea not quite ready for prime time.

Storage of the captured carbon is also going to be a huge issue.  Where and how much does it cost in resources.

I agree withy you when you say:

We want to reduce usage and work on technologies that would enable more radical reduction so that if it becomes necessary to stop further increases in CO2 levels it won't be quite that painful.

But I think the way to reduce coal use is to just start the process of slowly banning it not converting to a technology which will actually burn more of it and in the process make the coal industry even wealthier and more powerful.  Efficiency improvements, conversion to alternate power sources, reducing growth, shrinking population, lowering standards of living all seem to be better approaches than CCS.  We actually do need to have a war on coal.  We need to kill it.

If we take the resources which would be expended on CCS and spend that on alternatives while we are killing coal won't we be far better off in the long run?

[Richard Rathbone]

Another big issue with the CCS technology is that I have read we are a decade or more from having the technology all worked out.  Another idea not quite ready for prime time.

It was sorted decades ago. Its the policies not the technology thats lacking. Where the policy makes it the economic thing to do, as it does for CO2 rich natural gas in Norway, it already happens.

I don't think it will actually ever happen on a significant scale for coal, because the extra cost will mean other power sources outcompete coal and the effect will be to drive coal out of business for most power generation, but put a high enough price on emitting CO2 to the atmosphere and CCS happens.

[JimD]

Another big issue with the CCS technology is that I have read we are a decade or more from having the technology all worked out.  Another idea not quite ready for prime time.

It was sorted decades ago. Its the policies not the technology thats lacking. Where the policy makes it the economic thing to do, as it does for CO2 rich natural gas in Norway, it already happens.

I don't think it will actually ever happen on a significant scale for coal, because the extra cost will mean other power sources outcompete coal and the effect will be to drive coal out of business for most power generation, but put a high enough price on emitting CO2 to the atmosphere and CCS happens.

Richard,

You always seem to have your arguments together.  Note I was really talking about CCS and coal plants specifically.

Could you comment on this link from Climate Progress which indicates that there are still issues to work out. 

...My bottom line:  There are simply too many unanswered questions for anyone to say today that we could rely on large-scale deployment of CCS in the 2030s as a major climate solution...

http://thinkprogress.org/climate/2011/11/26/376257/carbon-capture-and-storage-permanence-feasibility-and-safety-issues/

[Richard Rathbone]

Its a lot of straw men.

Plenty of other pollutants are already regulated and controlled. CO2 is easy compared to them. e.g. CO2 emission is easier to monitor than SO2 emission and CO2 injection is easier to monitor than injection of fracking wastes.

You don't pay anyone to inject CO2. You make them pay to pollute the atmosphere with CO2.

CCS isn't a solution for the climate, the solution for the climate is to regulate CO2 emissions. 

[wili]

Here's another interview with KA and a video of his presentation at the conference (I assume).

http://www.resilience.org/stories/2014-01-06/radical-emissions-planning-kevin-anderson-interview

I note that here he present 2 degrees as the temp to stay below, even though in the past he and others have said that this is far too high a temp for any kind of safe climate. What do people make of this shift?

[JimD]

The only way to know for sure is the passage of time to which will allow one to determine if it was just a slightly different wording than he normally uses (easy to do in an interview when talking off the cuff) or whether he has capitulated a bit. 

Capitulation is certainly possible given the likelihood of where we are heading.  I note that we are starting to see a lot of comments that just assume 2C is going to be blown by and we might need to shoot for 3C.  If Anderson and Hanson insist that we dare not go above 1.5 (or something like that) when everyone knows that we are really looking at double that no one will pay any attention to them pretty soon.   Maybe 350.org will rename itself to 400.org this year as we are not liable to see that number again for a couple of hundred years.

[Shared Humanity]

The only way to know for sure is the passage of time to which will allow one to determine if it was just a slightly different wording than he normally uses (easy to do in an interview when talking off the cuff) or whether he has capitulated a bit. 

Capitulation is certainly possible given the likelihood of where we are heading.  I note that we are starting to see a lot of comments that just assume 2C is going to be blown by and we might need to shoot for 3C.  If Anderson and Hanson insist that we dare not go above 1.5 (or something like that) when everyone knows that we are really looking at double that no one will pay any attention to them pretty soon.   Maybe 350.org will rename itself to 400.org this year as we are not liable to see that number again for a couple of hundred years.

Wouldn't this be a little like the North Carolina State Legislature which passed a law prohibiting sea level rise this century.

[JimD]

That is one way of looking at it.

But it could also be a tactic used to try and still have some kind of influence on the debate.  If one is advocating a position which events have demonstrated is out of the range of any kind of possibility it will not be long before even those who agree with your goals no longer pay attention to what you say.  If getting to 350 has become an unrealistic goal you move the goal line a bit so to speak.  People do this kind of thing all the time and it is not always a conscious decision but sometimes the pressure of events causes the change and people are not even aware that they are doing it.

But I was just speculating and have no idea if he has changed or not.

[ccgwebmaster]

But it could also be a tactic used to try and still have some kind of influence on the debate.  If one is advocating a position which events have demonstrated is out of the range of any kind of possibility it will not be long before even those who agree with your goals no longer pay attention to what you say.  If getting to 350 has become an unrealistic goal you move the goal line a bit so to speak.  People do this kind of thing all the time and it is not always a conscious decision but sometimes the pressure of events causes the change and people are not even aware that they are doing it.

This shifting of the goal posts has been going on for quite a while, bearing in mind that back in the 90's it was determined (considerably more scientifically than the current 2C "goal") that 1C was a sensible safe upper limit. Certainly the breadth and severity of the changes we are now seeing at somewhat under 1C would tend to support that original assertion and perhaps even tend to lower the "safe" limit (as we appear firmly on track to transform the Arctic into a mode of operation far beyond anything recent at under 1C, with substantial consequences).

While I can see people are amending their positions in order to stay within the debate and in acknowledgement of the impossibility of staying within the limits previously suggested as safe - this is disingenuous in the extreme. They - and we - all know those limits (and likely also the new ones) cannot be achieved. There is no reason to think they can or will be achieved as the action required to go so grows more year on year just as surely as we are continuing to accelerate in diametrically the wrong direction.

It would be much more honest to say that we are now committed to limits beyond safe, that our future outcomes are "no longer compatible with a global organised community" (I paraphrase Kevin Anderson) and to change the message and the plans accordingly.

It is misleading and worse - dangerous - to keep shifting the limits and pretending that we still have a chance to navigate through this on the original premises advised (particularly with no sign of even limited action to start that navigation at this point).

More honest now to move the debate on - to say we know we are going to fail, and to ask what we can do to mitigate that. To continue to delude ourselves and each other is to erode even that opportunity...

[JimD]

ccg

I agree with you completely.  Thus my tendency towards posts which are on the extreme end of what is being discussed.  And a big reason why I have just as much animosity towards the Green-BAU folks like Romm.  He is a perfect examples of someone moving the goal posts (whether consciously or unconsciously).

We are long past the place in time where there was any practical chance of getting out of this mess relatively unscathed.  Yet a great many of the people who are fully cognizant of the situation we are in are completely incapable of accepting the conclusions of what that means.  So we dither.  And the longer we do that the worse the eventual outcome is going to be.

The world as structured presently is a dead man walking.  But civilization is not yet doomed.  But we can sure make that happen if we refuse to accept reality and deal with it.  Being a pretty realistic person (at least in my own mind) I do not see a major change in basic human behavior all of a sudden happening (since we are not rational creatures you cannot expect us to act rationally).  So we are screwed.  We will not appropriately react until panic sets in and triggers our evolved subconscious survival instincts.  At which point we get completely ugly with each other.

Or maybe a miracle happens and we will be saved.

[Laurent]

Jimd (and others)

Do not panic, what ever happen, stay cool, the only way to deal with the AGW is to do what you think the answer is. Like the Gandi statement "be the change that you want to see in the world"

May be one day someone will follow...and stay oppened to others ideas...

[JackTaylor]

Jimd (and others)

Do not panic, what ever happen, stay cool, the only way to deal with the AGW is to do what you think the answer is. Like the Gandi statement "be the change that you want to see in the world"

May be one day someone will follow...and stay oppened to others ideas...

So True.
We have to deal with AGW unless there is some sort of escapist plan available I'm not aware of. 

But, if there is NOT a significant - sufficient event to cause action, meaning just a continual - gradual warming, will there ever be action sufficient to slow - stop - reverse the warming?

Too bad my crystal ball got fractured.

[ccgwebmaster]

But, if there is NOT a significant - sufficient event to cause action, meaning just a continual - gradual warming, will there ever be action sufficient to slow - stop - reverse the warming?

I think that is precisely the point. There will not be significant action to slow, stop or reverse warming (save by civilisation collapsing and mass mortality really setting in). It is increasingly impossible given the laws of physics, let alone human behaviour and logistical issues.

Therefore realistic planning is now more a question of survival and mitigation in the face of large amounts of damage (to our civilisation, knowledge base, environment, etc etc), ideally with a long term goal that would prevent the mistakes being replicated (ie predicate the future upon sustainable but ideally still progress capable foundations).

If that is not undertaken soon (the signs are that it may not be) - in the coming months, years and at most optimistic decades - then the stakes increasingly move closer to simple survival and a much harder and longer climb for any sort of ultimate recovery (millennia instead of centuries).

[JackTaylor]

ccgwebmaster: Reply #24;

About when should one predict more than 50% of the Earths current habitable (agriculture) area will exceed survivable temperature (wet bulb)?

[wili]

Here's an piece on the original article: http://www.purdue.edu/newsroom/research/2010/100504HuberLimits.html



This is for a 12 degree C warmer (than now) global temp. Not many are thinking that this will come to pass this century, but we keep hearing about higher levels of sensitivity. ASLR on another thread just proposed that we could reach 8 degrees C higher by 2100.

35 is the WBT where everyone dies. Crops and humans trying to do any productive work give out at least a couple degrees below that. So on this map, everything in yellow and up is going to exceed habitability.
Note that these include:
--Eastern China
--most of the Indian subcontinent
--all of AMEG
--all of OZ
--most of South America
--the eastern half (or more) of the US (the west will be desert by then--not wet enough for high WBTs, but not arable, either)
--southern Europe

So yeah, most of what the places where people live and where people grow food will not be inhabitable, either because of WBT or because they will be desert (too dry for WBT).

[ccgwebmaster]

So yeah, most of what the places where people live and where people grow food will not be inhabitable, either because of WBT or because they will be desert (too dry for WBT).

People can move. Throughout human history, people have moved around. Your map still shows significant areas where wet bulb is survivable - some of which may well have viable climates (albeit I grant it would take time for all that to settle down). Consider the wide range of human adaptation in the absence of modern technology - ie look at the spectrum from aboriginal australians to eskimos and ask a simple question - why can people (and some sort of a civilisation) not continue in those habitable areas that remain even at an average warming of 12C or beyond?

For almost any person living in one of the inhabited areas today - sure - your whole world will be destroyed. Everything (and likely everyone) you ever knew will be gone. Your descendents (should any survive) will inherit next to nothing from you or your society (which did its best to murder them and deny them a future, an inheritance worse than nothing).

But the loss of your individual world, of everything that you knew - that is not the end of every world or everything. And maybe it's easier for me to say this as someone who never had roots, who never learned to call any one place home - who never truly integrated into the western society on whose fringes I have subsisted - but if you had or did any of those things, the challenge is simple enough - learn to let go.

The irony is that I think most people will doom themselves by being incapable of such a simple notion as letting go of their perceived world. Not only is that sort of how we got to where we are - but it's also what will stop people from considering their options and planning accordingly. Clinging to what is familiar likely means going down with the ship.

ccgwebmaster: Reply #24;
About when should one predict more than 50% of the Earths current habitable (agriculture) area will exceed survivable temperature (wet bulb)?

I have no idea. I could look at various pieces of research and pull a number out of a hat I suppose, with a certain amount of stated assumptions at work - but it would be a guess and likely a bad one given uncertainties around:

• magnitude, rate and threshold of onset for major earth system feedbacks
• additional anthropogenic emissions and changes
• rate and threshold of onset for collapse

Does the question matter though? If there remains even 1% of the planet within habitable parameters and people are able to survive there, there remains the theoretical prospect of our surviving and continuing into a better future.

Most of our destruction is and will be self destruction - we will do the most damage to our own prospects even into the later stages of all this, by competing with each other for dwindling resources (and consuming further resources for this competition). Even so - collapse should ultimately greatly diminish our ability to compete with each other on such terms if not potentially ultimately eliminate it.

[Shared Humanity]

From that  map,  it sure  looks like  moving to the mountains might be a good strategy.

[JackTaylor]

Shared Humanity: Reply #27 above;
#1.  I have no idea.
#2.  Does the question matter though? If there remains even 1% of the planet within habitable parameters and people are able to survive there, there remains the theoretical prospect of our surviving

#1.  Good to hear you say that.

#2.  It truly matters only in the context of having a conversation.
Supposedly through DNA research, some 70 - to - 80 thousand of years ago (  http://en.wikipedia.org/wiki/Toba_catastrophe_theory  ) the human population bottle-necked down to only a few thousand, and now it is a few billion.

To put another question up, not necessarily you (SH) alone to answer - speculate on.

What is the estimated minimum number of survivors to continue the human species
in the event of Cataclysmic Anthropogenic Global Warming?
(note: Not volcanic winter nor asteroid - meteorite event. But only AGW)

[JimD]

Jack

I will ask my daughter.  She has a masters in forensic science and is a specialist in DNA analysis.  She might know.

[JimD]

Jack

It turns out Wiki has a page on this stuff.

It is called Minimum Viable Population.

MVP and extinction[edit]

 In 1912, the Laysan Duck had an effective population size of 7 at most.
MVP does not take human intervention into account. Thus, it is useful for conservation managers and environmentalists; a population may be increased above the MVP using a captive breeding program, or by bringing other members of the species in from other reserves.

There is naturally some debate on the accuracy of PVAs, since a wide variety of assumptions generally are required for future forecasting; however, the important consideration is not absolute accuracy, but promulgation of the concept that each species indeed has an MVP, which at least can be approximated for the sake of conservation biology and Biodiversity Action Plans.[2]

There is a marked trend for insularity, surviving genetic bottlenecks and r-strategy to allow far lower MVPs than average. Conversely, taxa easily affected by inbreeding depression – having high MVPs – are often decidedly K-strategists, with low population densities while occurring over a wide range. An MVP of 500 to 1,000 has often been given as an average for terrestrial vertebrates when inbreeding or genetic variability is ignored.[3][4] When inbreeding effects are included, estimates of MVP for many species are in the thousands. Based on a meta-analysis of reported values in the literature for many species, Traill et al. reported a median MVP of 4,169 individuals.[5]

So 4000 or so I guess.  But the big caveat to me in this number is that this population has to be collocated so that they can breed properly.  It can't be scattered across the globe and then each little group would inbreed and die out.  So in practical terms if you have a group somewhere which meets the 4000 number then there are going to be lots of others scattered around the world as well.  So it really means a few hundred thousand probably.

[Shared Humanity]

Jack

It turns out Wiki has a page on this stuff.

It is called Minimum Viable Population.

MVP and extinction[edit]

 In 1912, the Laysan Duck had an effective population size of 7 at most.
MVP does not take human intervention into account. Thus, it is useful for conservation managers and environmentalists; a population may be increased above the MVP using a captive breeding program, or by bringing other members of the species in from other reserves.

There is naturally some debate on the accuracy of PVAs, since a wide variety of assumptions generally are required for future forecasting; however, the important consideration is not absolute accuracy, but promulgation of the concept that each species indeed has an MVP, which at least can be approximated for the sake of conservation biology and Biodiversity Action Plans.[2]

There is a marked trend for insularity, surviving genetic bottlenecks and r-strategy to allow far lower MVPs than average. Conversely, taxa easily affected by inbreeding depression – having high MVPs – are often decidedly K-strategists, with low population densities while occurring over a wide range. An MVP of 500 to 1,000 has often been given as an average for terrestrial vertebrates when inbreeding or genetic variability is ignored.[3][4] When inbreeding effects are included, estimates of MVP for many species are in the thousands. Based on a meta-analysis of reported values in the literature for many species, Traill et al. reported a median MVP of 4,169 individuals.[5]

So 4000 or so I guess.  But the big caveat to me in this number is that this population has to be collocated so that they can breed properly.  It can't be scattered across the globe and then each little group would inbreed and die out.  So in practical terms if you have a group somewhere which meets the 4000 number then there are going to be lots of others scattered around the world as well.  So it really means a few hundred thousand probably.

As things begin to get scary, we could choose to set up highly integrated pockets of humanity (including genotypes from across the planet) in areas where pockets of humanity will likely survive. This would get rid of the inbreeding issue.

[JackTaylor]

Jack

It turns out Wiki has a page on this stuff.

It is called Minimum Viable Population.

Didn't think to search for that (MVP) or similar - Thanks.

Now I'm off to search for minimum earth area to support approx 5,000 people for approx 1,000 years.

Wet frozen ground in back-yard garden & unable to use my FF-ICE tiller to play in the dirt.
Lots of time to ask - discuss for a couple weeks it looks like.

About 4 - miles NW of Greenville, SC USA. (34.899750 N, 82.429791 W)
(satellite and magnify for < 1/3 acre of garden)

[ccgwebmaster]

So 4000 or so I guess.  But the big caveat to me in this number is that this population has to be collocated so that they can breed properly.  It can't be scattered across the globe and then each little group would inbreed and die out.  So in practical terms if you have a group somewhere which meets the 4000 number then there are going to be lots of others scattered around the world as well.  So it really means a few hundred thousand probably.

If you are saying 4000 is a minimum to avoid inbreeding problems - what if you selected the initial smaller population specifically to maximise genetic diversity? Is that 4000 a population pulled at random globally? Or a section pulled from a more homogenous base - ie just about any nation on earth today? If you pulled 100 people of asian descent from the same town in China that is surely very different from a random or seeded sampling globally.

To what extent can inbreeding problems be overcome by the simple fact that the weak die in a harsher world? How severe a problem is it if mild? Many pets today are substantially inbred, and yet still live and are maintained indefinitely?

4000 seems a rather large number to me if you consider hunter gatherer tribes before people started to settle and practice agriculture. Are we really saying we think the old hunter gatherer tribes were that big? Given the tiny population density per hectare hunter gathering can support it seems rather unlikely to me - although I grant there might - occasionally - have been opportunities to exchange genetic material with other small tribes. However this would mostly have been through conquest or meeting at the boundaries of territories one supposes?

To my mind with low head count planning it is important to have diversity in the population. Although it goes contrary to most peoples behaviour to favour or support tribes other than their own - that means more successful small groups are likely to be those with high initial diversity. A bunch of affluent white people retreating to their doomstead may well inbreed and die out over a few generations, particularly given the harshness of the world they will be trying to adapt to. A random sampling including a decent portion from Africa could do a lot better (there is the most genetic diversity in Africa is my understanding). Not only would they have more diversity to start from - but likely be tougher and more resilient as individuals anyway.

I think it's worth noting that billions of members does not mean our species automatically has any more genetic diversity than if only a million people were alive further back in our history. It means we inflated our numbers - for that to turn into meaningful genetic diversity would take far longer than the time in which such a large population existed.

However, inasmuch as we already have one genetic bottleneck in our past (~75kya) - we may still be recovering from that... which is unhelpful in this context.

[ccgwebmaster]

As things begin to get scary, we could choose to set up highly integrated pockets of humanity (including genotypes from across the planet) in areas where pockets of humanity will likely survive. This would get rid of the inbreeding issue.

I just had a look at the page and can make a few more observations:

Minimum viable population is usually estimated as the population size necessary to ensure between 90 and 95 percent probability of survival between 100 to 1,000 years into the future.

Referring to that - and other things on the Wiki page - it seems clear to me 4000 is far more authoritative. That is an average number for a terrestial vertebrate in the wild without human (artificial) intervention.

Furthermore it is a statistical measure designed to have a 90-95 percent probability of longer term survival. If you significantly cut the number of individuals - obviously you would reduce the changes of long term survival, but I don't see why a much smaller population cannot be viable. The probability of them being so is less, I grant - but still present. And 100 small groups would need a success rate < 1% to statistically all die out.

Also the attribution to behaviour in the wild is significant. I have to suspect people could perform somewhat better just through some amount of common sense - for example - trying to avoid inbreeding (which we already do!). How many animals are intelligent enough and have enough understanding of genetics to make medium to long term decisions with the specific objective of avoiding inbreeding?

Therefore it seems to me 4000 is still a pretty generous number to think in terms of and that in principle you could get this number a lot lower if:

• you genetically seed the input population for maximum diversity
• you apply organised strategies to prevent inbreeding
• you accept a less than 90-95% confidence in long term viability

I wager a few hundred people split into several groups that were destined to meet within a century could be viable, at least theoretically. Personally I would expect to make an attempt with only a few tens of people and give it a damn good shot.

[JimD]

I think you are probably right that if we could preselect our gene pool and then rigorously manage the mating sequence it would not require the 4000 individuals.  But we might be making assumptions here that the scientists who are experts in this have already taken into account. 

But executing all of that requires common sense, a good knowledge of genetics and breeding, and the ability to actually enforce the proper selections of mates.  What is the likelihood of any of that?

BTW as a former dog breeder I can assure you that ALL purebred dog breeds are just chock full of genetic problems and disorders.  Most breeders cull the pups to eliminate the obvious defectives, later on as the dogs develop other problems become evident and a further culling process occurs.  And even following all of that it is not uncommon for dogs which the breeders thought were perfect and that they are using to further the breeding lines turn out to have significant issues and they have to be removed from the breeding stock.   Pure bred dogs have amazing specific abilities we have managed to select for, but they are a genetic mess. 

And there is the additional issue of the complexity of the human brain as compared to the other species.  I would expect inbreeding to manifest many problems in this area that would not occur with a species like dogs.

[Shared Humanity]

4000 seems a rather large number to me if you consider hunter gatherer tribes before people started to settle and practice agriculture. Are we really saying we think the old hunter gatherer tribes were that big? Given the tiny population density per hectare hunter gathering can support it seems rather unlikely to me - although I grant there might - occasionally - have been opportunities to exchange genetic material with other small tribes. However this would mostly have been through conquest or meeting at the boundaries of territories one supposes?

The Khoisan, the last significant surviving culture of hunter gatherer groups can shed light on this question. They now occupy only the deserts of southwest Africa but previously populated all  of Africa south of the Congo. They were pushed into the marginal areas of desert by the expansion of Bantu past the rain forests of the Congo.

While the individual groups frequently don't number more than 40 individuals, their nomadic lifestyles allow separate groups to gather frequently and individuals (young women most often) migrating to other groups was common practice. It serves to strengthen both groups as they could mitigate the impacts of mortality on each group. Anthropologists also argue that it strengthened the ties between individual groups, fostering harmony and anchoring the larger culture.

[ccgwebmaster]

The Khoisan, the last significant surviving culture of hunter gatherer groups can shed light on this question. They now occupy only the deserts of southwest Africa but previously populated all  of Africa south of the Congo. They were pushed into the marginal areas of desert by the expansion of Bantu past the rain forests of the Congo.

I think that's a very interesting example. I've started another topic intended to cover small group logistics as the link to the Tyndall centre, or even to carbon dioxide reduction rates and outcomes seems a little stretched.

https://forum.arctic-sea-ice.net/index.php/topic,716.0.html

[JimD]

Its a lot of straw men.

Plenty of other pollutants are already regulated and controlled. CO2 is easy compared to them. e.g. CO2 emission is easier to monitor than SO2 emission and CO2 injection is easier to monitor than injection of fracking wastes.

You don't pay anyone to inject CO2. You make them pay to pollute the atmosphere with CO2.

CCS isn't a solution for the climate, the solution for the climate is to regulate CO2 emissions.

Either I don't understand what you are trying to say or I guess I need a lot more convincing as the more I find on CCS prospects the more it seems unlikely.  And not just from a policy point of view but especially from a technical point of view.  Take a look at the below link.  It seems to be a pretty comprehensive analysis and the conclusions are pretty negative.

A new survey finds a sharp drop in large-scale integrated projects to capture CO2 from energy systems and bury it underground. This drop from 75 projects to 65 over the past year is yet more evidence that we shouldn’t expect large-scale deployment of carbon capture and storage (CCS) before the 2030s at the earliest, nor expect that CCS would provide more than 10% of the answer to the carbon problem by 2050....

The 200-page Global CCS Institute study, “The Global Status of CCS, 2013,” doesn’t offer much to be optimistic about. The New York Times summarized the findings with this headline, “Study Finds Setbacks in Carbon Capture Projects.” The Times reports:
 
… the technology for capturing carbon has not been proved to work on a commercial scale, either in the United States or abroad....

Let’s start with “the daunting scale of the challenge,” as Vaclav Smil explained in “Energy at the Crossroads“:

“Sequestering a mere 1/10 of today’s global CO2 emissions (less than 3 Gt CO2) would thus call for putting in place an industry that would have to force underground every year the volume of compressed gas larger than or (with higher compression) equal to the volume of crude oil extracted globally by [the] petroleum industry whose infrastructures and capacities have been put in place over a century of development. Needless to say, such a technical feat could not be accomplished within a single generation.”....

That sure sounds like an immature solution to me.

http://thinkprogress.org/climate/2013/10/10/2766611/carbon-capture-storage-2/

[Shared Humanity]

Thanks, ccg. I'll go over and take a look.