Systemic Collapse: The Basics

[Falcon]

If you'd prefer me to use the term neo-malthusian ideas, then I'd agree that that is probably more accurate.

I'd prefer it if you could refrain from using any pejorative label of any description, and confine your self to discussing the subject. I can't believe I'm that fascinating that you have to keep mixing me and the subject up.

 

[Dr Jon]

the green revolution partly enabled some most of the land to be brought into production

Corrected for you.


Do you seriously believe this could have happened without petroleum-driven machinery, petroleum-derived fertilisers, petroleum-derived pesticides and a growing population?

See:

India’s Farming ‘Revolution’ Heading For Collapse

The Limits To Growth And The Growth Of Despair

... when Norman Borlaug engineered the Green Revolution, the leaders of the aforementioned corporations, governments and NGOs announced that The Population Bomb was wrong. Long live Growth! They wouldn't hear Borlaug's other message, that he had given the world a 30-year reprieve in which to slay the "population monster." We didn't slay the monster. We adopted a conspiracy of silence on the subject of population. We went on talking about how we weren't "No growthers," allowing, for instance, the 3-decade US housing binge, capitalized on nothing but the American Dream, which is said ultimately to have resulted in the crash of 2008, from which John Q. Public has no end in sight.

 

[Falcon]

I*tbf, I do find some of the arguments pretty tiresome

OK. Well I think we should all be jolly good friends, and discuss this over macaroons and ginger beer. But that's just me.

 

[free spirit]

So as I understand it, we are heading to 9 billion, the earth might support 2/3 billion, managing that "gracefully" would take a century, the hydrocarbon supply currently powering the industrial agricultural system feeding two thirds of the projected population won't last a fraction of that, and it's Malthusian to suggest this is a problem?

You may have noticed, but I'm not a particularly strong advocate of the industrial agricultural system embodied in the green revolution, and certainly wouldn't see that it's replacement with a more sustainable agricultural system as being either a bad thing, or something that must inevitably lead to significantly reduced crop yields.

Conversely, the switch away from the use of huge amounts of chemicals on the land will have massive benefits for a whole swathe of other aspects of the situation such as water courses, fisheries, bees and pollination rates, disease and pest control, land degradation, water conservation etc etc. So while absolute yields in some areas may fall to some extent, overall yields could well increase.

This is particularly the case in a lot of the developing world where green revolution techniques were an abject failure, with a lot of that failure being responsible for the huge unpayable 2rd world debt. I'm talking about stuff like entire tractor fleets being found rusting in the fields 1-2 years after they'd been bought by those countries on the say so of the IMF / World bank, for want of spare parts, diesel etc etc. Or crops with supposedly massive increased yields being used in places where access to the chemical fertilisers and insecticides on which they rely for the increased yields wasn't going to happen.

Sustainable agricultural practices are usually far more appropriate to these situations than standard green revolution practices have proven to be, and will increasingly be so.

A ten year study of the yield improvements averaging 64% from the adoption of sustainable agriculture practices across 57 countries and 37 million hectares really shouldn't be brushed aside as easily as you seem to be doing, and really ought to cause any objective person to seriously re-evaluate their position on the subject.

I'll dig out the reference to the full report later, a quick overview is at the link I posted earlier here

I've not seen anything I recognise as a reply to my question about the estimates in more contemporary studies of the impact on carrying capacity of various deleterious impacts of climate change and biosphere malfunctions. Do you know them?

my comments about wild stabs in the dark would probably explain that. I don't really set much store by such estimates, so haven't spent much (any) time looking for them over the last few years.

However, if we were to take the study you quoted, and input up dated information into it about stuff like the sustainable agricultural practices yield potential, renewable energy potential, energy efficiency potential, improved fisheries potential from sustainable agriculture practices etc etc etc and not assume another 30 years of land degradation at 1990's rates (which is all part of sustainble agriculture practices), then it's fairly clear that the figure is going to be significantly higher than the 2 billion you keep repeating.

That figure also entirely depends on the average standard of living assumed. That report is based on an average of European standards of living. Adjust this assumption, and the carrying capacity figure will increase accordingly, which is just one of the reasons that I object to the way you bandy these figures about as you do.

 

[free spirit]

Corrected for you.


Do you seriously believe this could have happened without <snip>and a growing population?

That's a big "and" you've added at the end there, and no, obviously I don't believe it could or would have happened without a growing population, but that's pretty much my point is it not?

a huge amount of that land was brought into production had little or nothing to do with oil as such, it was brought into production through slash and burn techniques to clear forests and use the land for agriculture, and folk were making fire a loooong time before fossil fuels appeared on the horizon.

A lot more was brought into production through the processes of migration, and fencing off of previously wild land in places like Australia, Africa, USA and Canada.

Then there's land that was drained or irrigated to bring it into production. Now, it probably is true that most of this drainage and irrigation was done by machines powered by fossil fuels, but this process had also been taking place for centuries before this option was available (think the netherlands, east anglia etc), and this machinery could as easily be renewable powered as oil powered... plus if it's already cleared / drained / had the irrigation systems put in place, then maintaining that is far less energy intensive than doing it from scratch.

 

[free spirit]

Corrected for you.


Do you seriously believe this could have happened without petroleum-driven machinery, petroleum-derived fertilisers, petroleum-derived pesticides and a growing population?

See:

India’s Farming ‘Revolution’ Heading For Collapse

1 - That's talking about land that was already farmed, but where green revolution techniques and crops were used to increase yields from that land. That doesn't support your case at all on the amount of land being used issue.

2 - I in no way take issue at all with the article or it's findings. I'm an environmentalist ffs, I'm well aware of the major problems with the green revolution methods in places like India and am in no way asserting that they can or should be continued, and never have.

What I'm saying is that sustainable farming techniques that greatly reduce resource usage have been demonstrated to be capable of maintaining or increasing yields in many situations. Possibly not to the level of the best of the green revolution yields, but there are still large areas of the world with pre-green revolution type yields where significant yield increases from these sustainable farming methods ought to be possible, which to a significant extent should be able to offset at least a significant part of any reductions in yields at the most productive of green revolution farms.

The Limits To Growth And The Growth Of Despair

So, the green revolution's foremost member stated that it wasn't sustainable from the start but was ignored.

tbh, I'm not really sure what point I'm supposed to be taking from this article, as I agree that it isn't and never was sustainable, and would much prefer that the world had adopted sustainable farming practices back in the 60's instead of going down the red herring route of the 'green revolution', resulting in massively degraded land across vast swathes of the world.

Sustainable farming practices though are capable of bringing much of that degraded land back to being decent quality, and preventing the rest of the land from further degrading at the same time.

 

[Dr Jon]

Then there's land that was drained or irrigated to bring it into production. Now, it probably is true that most of this drainage and irrigation was done by machines powered by fossil fuels, but this process had also been taking place for centuries before this option was available (think the netherlands, east anglia etc), and this machinery could as easily be renewable powered as oil powered... plus if it's already cleared / drained / had the irrigation systems put in place, then maintaining that is far less energy intensive than doing it from scratch.

Yeah. But the point I'm trying to make is that petroleum has amplified our ability to exploit the environment for our short-term economic benefit, leaving it too exhausted to provide for our needs without it.

On a more positive note, I just spotted:
Gujarat Solar Park: Asia's largest solar power park opens

but:
Forests equal to half of Delhi lost

Ho hum...

 

[free spirit]

Yeah. But the point I'm trying to make is that petroleum has amplified our ability to exploit the environment for our short-term economic benefit, leaving it too exhausted to provide for our needs without it.

that may be the point you're making now, but you've yet to concede that taking the pre-oil population figure as being in any way indicative of the carrying capacity of the world post oil would be wrong.

The most blatant reason being that a far smaller area of land was under cultivation when population was at 1 billion (around 1800) than is the case now.

This is largely a separate point to the green revolution's yield increases, although you are right that a proportion of this land was brought into production due to oil based machinery, this land will mostly remain available even after the oil goes if sustainable techniques are used to keep it in production.

If you'll accept that fairly straight forward point and then stop using that 1 billion figure then we'd have made some progress tonight.

 

[free spirit]

here's the link to the full study I referenced earlier

"Resource-Conserving Agriculture Increases Yields in Developing Countries", Pretty et al, 2006

Graph showing the yield increases for various crops within the study below.

 

[Dr Jon]

If you'll accept that fairly straight forward point and then stop using that 1 billion figure then we'd have made some progress tonight.

As I said before, 1 billion is the worst-case. I can't be certain of anything else.

 

[free spirit]

As I said before, 1 billion is the worst-case estimate. I can't be certain of anything else.

it's not worst case, it's utterly unsupported by the evidence case.

seriously, I really don't see why you won't just accept that the figure is wrong given that it's so obvious that your original premise for using it is false.

I'll put attempt to put some figures into this though.

The total area of land under cultivation increased by 466% between 1700-1980* - sorry, I can't actually find the figures for 1800-2010.

So even if yields per hectare were to sink to those levels, which I don't think for a second is likely or necessary, if agricultural output is to be the determining factor you're using, then your worst case scenario ought to be 466% greater than the population in 1700, so 610million x 5.66 = 3.44 billion.

But I don't really accept that premise as being at all likely. At worst I'd think we ought to be applying that 64% yield improvement from sustainable agriculture practices to it, which'd give 5.64 billion as a ball park minimum figure for a sustainable population figure based on sustainable agricultural output with minimal greed revolution type input.

Obviously, if we want to increase per capita food intake / eat a lot of grain fed meat or something, then that figure would be reduced, but that'd be the worst of base level worst case scanario figure that I'd accept could be in the right sort of ball park.

My opinion though would be that this figure could be significantly increased given that the best yield increases in that study were far higher than the average, and I'd think that lessons learnt from those situations ought to result in significant further average yield increases if applied more widely. There is also still seriously big areas of land that could be brought into production if it was a choice between that and billions dying.

Personally, I seriously start struggling to see how we'd possibly feed everyone sustainably when population starts getting above 8-9 billion or so, and suspect that the maximum sensible sustainable long term global population in a world without significant fossil fuel energy inputs is likely to be in the region of 5-7 billion depending on the desired per capita food intake, dietary mix, and the impact of climate change and other land degradation processes currently happening.


*wiki sources this figure to Matson et el, 1997, science, but I don't have access to that journal to verify it.

 

[Falcon]

A ten year study of the yield improvements averaging 64% from the adoption of sustainable agriculture practices across 57 countries and 37 million hectares really shouldn't be brushed aside as easily as you seem to be doing, and really ought to cause any objective person to seriously re-evaluate their position on the subject.

If the industrial agriculture carrying capacity is 9 billion, and the pre-industrial carrying capacity was 3 billion, and it will take 100 years for population figures to reduce through natural birth/death rate equilibration, then the required short term yield improvement is 300%.

You are telling us that we might expect 64% if the gains that were sustained in presumably the best candidates can be sustained across the entire portfolio. That leaves (9 - 3 x 1.6 = ) 4 billion at risk, to be protected through some combination of hydrocarbon extension, crop yield improvement, diet, and birth control. Not only can hydrocarbon not be extended, it must be immediately curtailed, possibly by as much as 80%.

You are further telling us that you don't know what the impact of climate change (drought) and bioservice impairments are likely to be on that 64%, apparently because the studies that estimate those impacts are so poor, while lambasting me for lack of objectiveness and failing to re-evaluate my position.

I don't mind that your numbers are hokey. What I mind is that you hide hokey numbers behind ad hominem attack and bluster.

 

[Falcon]

From a recent paper by the guys at NOAA and US National Labs, "Projections of Future Drought in the Continental United States and Mexico". The plot shows a forecast of US/Mexico drought severity under the A1B emission scenario (which we are tracking above i.e. the A1B model is optimistic). The model under predicts 20th Century drought severity i.e. the forecast is likely to be optimistic.

The average drought by the end of the century is forecast by current climate change authorities to be 0.6. The drought in the dustbowl of 1930's was 0.6.

(reference)

Meanwhile, drought has *reduced* Mexican agricultural production by 40% (ref)

Mexican farmers have lost 2.2 million acres (900,000 hectares) of crops to dry conditions and 1.7 million farm animals have died this year from lack of water or forage, according to the nation’s Agriculture Department.

This is the context in which free spirit is forecasting substantially elevated crop yields relative to pre-industrial conditions, and calling for re-evaluation of my position.

 

[free spirit]

If the industrial agriculture carrying capacity is 9 billion, and the pre-industrial carrying capacity was 3 billion, and it will take 100 years for population figures to reduce through natural birth/death rate equilibration, then the required short term yield improvement is 300%.

that's only based on your assumption that oil will suddenly be entirely unavailable. If you remove this assumption from the equation, then the picture is somewhat different.

You are telling us that we might expect 64% if the gains that were sustained in presumably the best candidates can be sustained across the entire portfolio.

no, as I've pointed out that was the average across an incredibly large study, not the best examples from the study.

The best examples from the study were around 500% increases in output, as you ought to be able to tell from the graph I posted. As I also stated, it'd be my opinion that once lessons are learnt from the better performing farms in the study and applied more widely that the 66% improvement figure could itself be significantly improved.

That leaves (9 - 3 x 1.6 = ) 4 billion at risk, to be protected through some combination of hydrocarbon extension, crop yield improvement, diet, and birth control.

agricultural land area increase should also be added in to that, but yes if the population stabilised at 9 billion then that's probably in the region of 3-4 billion above the carrying capacity of the land area currently being farmed based on average current sustainable farming practices alone.

Not only can hydrocarbon not be extended, it must be immediately curtailed, possibly by as much as 80%.

yeah, well I've dealt with that 80% figure already and you've not responded to that, so I'll not be wasting my time again.

You are further telling us that you don't know what the impact of climate change (drought) and bioservice impairments are likely to be on that 64%, apparently because the studies that estimate those impacts are so poor, while lambasting me for lack of objectiveness and failing to re-evaluate my position.

anyone who says otherwise, including you, are talking out of their collective backsides. They may make best guesses at it, but that's all they are, and certainly not something that you or anyone else should be using to produce figures that you then express with absolute certainty.

I don't mind that your numbers are hokey. What I mind is that you hide hokey numbers behind ad hominem attack and bluster.

and what do you call this if not an ad hominem attack and a lot of bluster?

you're also having a fucking laugh calling my numbers hokey, and please note the massive difference between the way I express my figures and the way you express yours - I'm clearly indicating they're only intended as rough ballpark / best guess type figures, you repeatedly refer to your figures in ways that make them appear to have far greater levels of certainty attached to them than is real. FFS even the report on which you base the figures you use doesn't support your figures in the way that you use them.

 

[free spirit]

As I said before, 1 billion is the worst-case. I can't be certain of anything else.

oh piss off then. I gave you the benefit of the doubt, but you're obviously just a clueless fuckwit.

 

[Falcon]

that's only based on your assumption...

Lots of words. Conspicuous silence on the impact of drought on your speculations. OK.

 

[Dr Jon]

oh piss off then. I gave you the benefit of the doubt, but you're obviously just a clueless fuckwit.

Thank you for your expert opinion.


Read and learn:

Probably what people are really contemplating is the maximum population the Earth can sustain indefinitely in some sort of steady-state. Or perhaps they really mean how many people can the Earth support until fossil fuels are depleted. I have been working on the steady-state problem for over a decade now, but considering mainly topsoil as the limiting resource. I now have annotated reviews of the global literature on topsoil loss, forest land degradation, grazing land degradation, irrigated land degradation, and fishery degradation. It has become clear that there is no need to worry about energy-- agricultural top soil and those dependent on it will vanish long before the last barrel of liquefied coal is gone.

The lifetime of past civilizations correlates well with their topsoil resources. Civilizations that had a river system that constantly replenished topsoil resources always lasted far longer than civilizations that did not. I argue that topsoil is still the limiting factor for modern-day civilizations as well. Below I run through a very rough outline of my arguments to give people an idea of key facts and figures. Ignored are such niceties as human rights, biodiversity, aesthetics etc. Man is considered as purely a mindless animal consuming food. This is the way to arrive at the most optimistic conclusions possible.

Irrigated land provides roughly 40% of the world's soil-based food supply. In the opinion of experts in the field, the ultimate fate of the world's irrigation systems will be much the same as the fate of irrigation systems of old--barren salt flats. This is apparently because few systems are underlain by drainage tiles for draining water away. Irrigation-system growth was one of the three main reasons why growth of global food supplies kept up with global population growth over the past 4 decades. Presently however, creation of new systems is roughly balanced by (and probably less than) the rate of irrigation-system abandonment due to salination and reallocation of water supplies to urban uses. The rate of abandonment is sure to increase dramatically in decades ahead because it takes some time for the effects of salt buildup to appear, and most irrigation systems are only decades old.

If one takes the most optimistic data on grassland photosynthesis and data on how much meat is produced per ton of grass and ton of grain, it becomes clear that the world's grasslands are overgrazed by a factor of about 2. This is easy to see from river-sediment data. Rivers draining the world's arid grasslands are "turbid" and remove several times as much sediment per acre per year as average sediment loss rates from average developed land. Most grazing-land sediment is sub-soil from erosion by gullies and stream banks, so actual topsoil losses may not be much greater than on croplands, but the basic erosion mechanisms (gullies, stream-bank erosion) are usually indicative of topsoil erosion on a massive scale--i.e. over grazing.

If one adds up the rates of topsoil deposition in oceans, river bottoms, dam backwaters and alluvial plains; then adds topsoil losses due to wind erosion, salination of irrigation systems, urbanization, and several other minor effects; then subtracts off topsoil losses from forest lands and urban lands, one gets a net topsoil loss rate from agricultural land of roughly 100 billion metric tonnes per year (100 Gt/year)--at least 5 times the rate of natural topsoil-creation on agricultural lands.

The global inventory of cropland topsoil is about 6500 Gt. Grazing land topsoil inventories are perhaps three time that (though an acre of grazing land is only about 1/6 as dollar-productive as an acre of cropland). The global inventory of top soil on potential (not yet used) croplands is several times 6500 Gt, but considering only potential croplands that can be cropped sustainably, the potential inventory is only perhaps 10 percent that of existing croplands--barely enough to replenish croplands abandoned due to degradation and urbanization for a few decades. This perhaps explains why the global cropland inventory has been constant since the early 1980s.

I am still working on how to apportion global agricultural topsoil losses between croplands and grazing lands, but I suspect the gross rates are not that much different. This would suggest a cropland topsoil loss rate of 50 Gt per year from a maximum inventory (actual plus potential) of at most 7000 Gt, suggesting a lifetime of human civilization of 7000/50 or 140 years. But now consider that once topsoil depths drop below the depth of the root zone (about 6 inches) cropland erosion becomes nearly irreversible and increases rapid. Current optimistic average depths of cropland topsoil are not over 11 inches, and some data say several inches less. So civilization has only about half of its topsoil to spend down before things get really bad. This gives a lifetime for human civilization of about 70 years--barely one human lifetime, and just an eye-blink in terms of human history.

How is this analysis translated into the number of people that the Earth can support sustainably? Assume that net agricultural topsoil loss rates are directly proportional to human population--an assumption that correlates well with global variations in topsoil loss. In order to reduce gross agricultural topsoil loss to the natural rate of agricultural topsoil creation, the Earth's population would need to fall to about a fifth of its present value--perhaps 1.2 billion. Escalation of irrigated land degradation due to salination could drop this figure to well under one billion.

Neglected here is cropland productivity growth due to genetic advances and increased use of fertilizer--the other two effects that largely supported population growth during the past 4 decades. However both of these effects are now close to saturation, so one should not expect really substantive increases in maximum population values from either of these effects. Increased use of pesticides to attempt to reduce crop losses from the present 10-20% of total production has never shown the ability to cut crop losses to pests, probably because increasing use of monocultures and shrinkage of the global plant gene-pool have worked to counteract whatever benefits pesticides might otherwise be expected to offer.

A far more likely steady-state scenario than human population falling to 1.2 billion is that cropland topsoil is largely destroyed, and the Earth becomes a waste land with populations held constant by war, disease, hunger, suicide and genocide. The productivity of sub-soil is not well known, though it is probably not over 10 percent of the productivity of topsoil. Hence the maximum population under the far more realistic steady-state scenario is probably under 10 percent of the maximum population that a not-erosion-limited, topsoil-based civilization can sustain--possibly 0.6 billion.

Fisheries have been neglected in all this. The problem with fisheries is that Man keeps fishing further and further down the oceanic- and fresh-water food chains, and the lower we go the more dispersed fisheries become. At the dispersion value of the open ocean where about 75 percent of oceanic life-creation occurs, fuel costs for fishing boats per ton of fish harvested increases by about a factor of 100 from present-day values. And present-day fishing-boat fuel costs are already a significant portion of the price people now pay for fish. Aquaculture imposes yet another demand on world grain supplies. So although it may provide a positive contribution to protein sources, its contribution to caloric supply is probably negative. And consider that aquaculture usually entails destruction of coastal wetlands, estuaries and mangrove swamps, all of which provide vital breeding grounds for 80-90 percent of ocean fish, and the frequently-diseased fish in ocean aquaculture pens often escape and devastate populations of their wild cousins. So it is not clear that aquaculture provides a net benefit of any kind.

And let us not forget hydroponics that some say permit a global population of 50 billion or so. Hydroponics is useful for producing the more expensive foods (fruits and vegetables) for wealthy First-World people. But the idea of using hydroponics to produce complete diets of average First World people, to say nothing of Third World people, strains credulity. Imagine how many fluorescent light bulbs would be needed to replace the sunlight over all the croplands of the world.

-- Bruce Sundquist, Carrying Capacity Committee, Allegheny Group, Sierra Club

The total area of land under cultivation increased by 466% between 1700-1980* - sorry, I can't actually find the figures for 1800-2010

And how did that happen?
Are you seriously saying this would have been possible without fossil fuel energy?

Also see:
Peak Oil, Carrying Capacity and Overshoot: Population, the Elephant in the Room

 

[SpineyNorman]

As I said before, 1 billion is the worst-case. I can't be certain of anything else.

Bit of a meaningless statement surely? Worst case scenario, I'd have thought, would be competition between states for diminishing resources, resulting in a nuclear war that kills us all. That's all you can be sure of.

And if it's a worst case scenario then you're clearly not sure of it.

Whereas I think Falcon talks about population because that's how he interprets the evidence, I get the impression that you genuinely want it to be the case that there will be a mass die off. It fits with your antinatalism and your propensity to stick your fingers in your ears and sing "lalala!" when someone who clearly knows what they're talking about points out the inaccuracies in your arguments.

 

[Falcon]

.

 

[SpineyNorman]

.

 

[elbows]

dash

 

[free spirit]

And how did that happen?
Are you seriously saying this would have been possible without fossil fuel energy?

well most of that increase in the area of land use for farming occurred before the green revolution, so yes mostly.

In the last 40 years, the area of global agricultural land has grown by 10%

[source]

The increase in land use for agriculture since the point when the world's population was last at 1 billion was mostly driven by population growth itself, as vast areas of the world were settled for farming through migration and colonisation.

Now, I suppose you could argue that this process was aided by steam boats and trains, and to some extent the potential to easily trade / export excess food that's grown. BUT, none of this alters the fact that the land is now in settled and in use for farming, and will still be available for use after peak oil, unless you're of the opinion that the residents of Australia, New Zealand, USA, Canada, much of Africa and Russia will simply pack up and leave that land entirely after peak oil.

Oil also has little to do with the slash and burn of forests to turn them into farmland, which was, and still is the other major sources of additional land for agriculture. Similarly, once this land is brought into agriculture, it's not just going to cease being available for use after peak oil.

The main area of land that could be argued was actually brought in to production through oil use would be irrigated land that was previously unproductive, but that's a relatively minor part of the overall increase since the global population was at 1 billion.

Oil's major input into this process has been to increase productivity levels, as well as increasing the ease with which the food grown can be transported to where it's wanted.

Simple fact is that using the 1 billion pre fossil fuel population level as being in any way indicative of the actual carrying capacity of the worlds farmland is completely nonsensical unless you factor in the massive increase in the area of agricultural land since that point.

 

[free spirit]

btw, posting opinion pieces written by people who can probably best be described as enthusiastic amateurs doesn't really do much to support the credibility of your position, though I've now remembered where it was that you originally picked up that 1 billion carrying capacity figure from.

How Many People Will Be Left?Taking the carrying capacity effects discussed above into account, I initially set the bar for a sustainable population at the population when we discovered oil in about 1850. This was about 1.2 billion people. Next I subtracted some number to account for the world's degraded carrying capacity, then added back a bit to account for our increased knowledge and the ameliorating effects of oil substitutes. This is a necessarily imprecise calculation, but I have settled on a round number of one billion people as the long-term sustainable population of the planet in the absence of oil.

So, your source for this figure also entirely ignored the actual increase in land being farmed, as well as any potential to increase yields vs the 1850 figures using more sustainable techniques.

But you're probably going to entirely ignore everything I say on this again and just keep on repeating this same figure despite it having no credible basis whatsoever.

 

[free spirit]

Lots of words. Conspicuous silence on the impact of drought on your speculations. OK.

I was trying to demonstrate the major obvious fallacy in the methodology Dr Jon had used to produce his 1 billion figure, rather than trying to produce an accurate estimate myself factoring in ever single factor possible.

But yes, obviously increased levels of drought will obviously have significant impacts. There's a lot of uncertainty involved there though with those predictions, and the predictions also show increased levels of rainfall in many other areas of the world, so it'd be pretty hard to accurately predict what impact these changes will end up having to global food production levels overall.

I'd struggle to see any justification for the sort of global yield losses from these drought hit areas that would lead to anything like the 2 billion carrying capacity you've repeatedly used.

Also, one factor in that sustainable agriculture study was a 70-250% increase in water productivity among all food groups other than rice (15% increase, but then most of the rice growing areas are in asia, where rainfall is predicted to increase anyway).

I'm in no way denying there are likely to be serious difficulties ahead, I'm just pointing out that I've not seen any evidence to support the sort of extreme low figures you and Dr Jon keep repeating for the earth's carrying capacity once the oil runs out, and that several of the assumptions that have been used to produce those figures are wrong.

 

[Falcon]

I'm in no way denying there are likely to be serious difficulties ahead, I'm just pointing out that I've not seen any evidence to support the sort of extreme low figures you and Dr Jon keep repeating for the earth's carrying capacity once the oil runs out, and that several of the assumptions that have been used to produce those figures are wrong.

Free spirit I suspect we are arguing for nothing, and probably agree over far more than we disagree. My only substantive point is that it is highly uncertain, and that in situations in which there is both high uncertainty and high risk potential, we need to act very conservatively. In my view, that means acting as if the pessimistic data was more likely until it is proven otherwise. This is not the same as claiming that highly pessimistic data is more accurate or, even worse, evidence of holding some ideological view point that fewer people is ontologically a better thing (the core of the Malthusian proposition).

 

[littlebabyjesus]

But you're taking different sets of pessimistic data and adding them together.

Now estimating the chance of various different scenarios is itself problematic. If you have three predictions that cover ranges that added together make the full range of reasonable possibilities, one of those predictions will be right, and the assumptions in the other two predictions will be wrong. With enough correct information, you would be able to say that one of those has a chance of 1 of happening and the other two a chance of zero. But you don't have full information - a situation which produces probabilities between 1 and 0. More than that, you don't actually know which information it is exactly that you don't have.

Bearing that problem in mind, let us assume that there is greater chance of the middle prediction and a lower chance of the ones to either side. If you're taking the upper prediction as your worst-case scenario, it may be estimated as having only, say, a 20 percent chance of happening. Again a big assumption, but assuming another independent factor with the same kind of range of prediction, if you add the worst-case scenario of this one to the first, you only have a 4 percent chance of them both happening. Add in a third, and the chance reduces to less than 1 percent.

Of course, many of these factors are not independent at all. It may be that if one happens, the chance of the second greatly increases. But it may also be that if one happens, the second cannot. You've got to be really really careful about adding together different predictions to produce an overall idea about what is likely to happen. Taking all the worst-case scenarios together is very likely to produce an unrealistically pessimistic idea of the future.

 

[Falcon]

But you're taking different sets of pessimistic data and adding them together etc.

You are using probability concepts to describe uncertainty (when the past provides no reliable guide to future events), when it can only be used to describe risk (when the regularity of past events is a reliable guide to the course of future events). Economics gets the two mixed up all the time (usually when they need a proxy for fundamentally uncertain phenomena in order to render them susceptible to computation), and so have you.

Of course, many of these factors are not independent at all

Precisely. In fact, as manifestations of the growth dependent dominant neoliberal capitalist form of the global political economy, climate change, environmental degradation, over dependence on oil, resource depletion, and population overshoot, are explicitly co-dependent. The uncertainties, while hard to quantify, are correlated. The proposition that cumulative uncertainty decrease as they are aggregated assumes a lack of correlation, and is therefore invalid.

 

[free spirit]

Free spirit I suspect we are arguing for nothing, and probably agree over far more than we disagree.

Actually, if you see the post on the global financial implosion thread written at the same time as this, you'll see me saying largely the same thing.

My only substantive point is that it is highly uncertain, and that in situations in which there is both high uncertainty and high risk potential, we need to act very conservatively. In my view, that means acting as if the pessimistic data was more likely until it is proven otherwise.

The high degree of uncertainty in the figures has been my major problem with your and Dr Jon's statements from the first point of disagreement, as you were stating them as if they were fact, rather than worst case scenario best guesses.

As I've also repeatedly stated, and point out in the post on t'other thread, whether you intend to or not, you have a tendency to portray all of this as being inevitable, which IMO let's governments and us all off the hook in the eyes of people reading it.

I don't think any of this is in any way inevitable, it's direct cause and effect of government policies, and consumer choices that have ignored these very real looming issues for the last 3 decades at least, and continue to largely ignore them now.

For example, had we not used the dash for gas as our short term method of reducing green house gas emissions (and breaking the power of the coal miners unions), and instead opted for a massive push into renewables, we could have had 20% of our electricity from renewables sources as Germany now has, or propably higher, along with the industry and exports that came to Germany from being early adopters, and we'd also still probably have enough gas reserves in the north sea to keep us from importing gas for heating for another 20-30 years at least.

Direct cause and effect of government policy has got us into this situation, and the potential to at least mitigate the worst of the problems is still there, so let's not let government off the hook even further by portraying the worst potential consequences as being inevitable.

This is not the same as claiming that highly pessimistic data is more accurate or, even worse

Unfortunately, that is how it comes across in a lot of your posts.

evidence of holding some ideological view point that fewer people is ontologically a better thing (the core of the Malthusian proposition).

I don't agree that this is the core Malthusian proposition at all, but if this is your interpretation of it, then I can see why you might object to the label.

IMO the core of the Malthusian proposition is the inevitability of the situation, which is why I've referred to your position as being Malthusian, as intentionally or not, you regularly portray this situation as if it is inevitable.

"The power of population is so superior to the power of the earth to produce subsistence for man, that premature death must in some shape or other visit the human race. The vices of mankind are active and able ministers of depopulation. They are the precursors in the great army of destruction, and often finish the dreadful work themselves. But should they fail in this war of extermination, sickly seasons, epidemics, pestilence, and plague advance in terrific array, and sweep off their thousands and tens of thousands. Should success be still incomplete, gigantic inevitable famine stalks in the rear, and with one mighty blow levels the population with the food of the world".

—Malthus T.R. 1798.​

​

An essay on the principle of population​

. Chapter VII, p61​

[3]​

 

[littlebabyjesus]

The proposition that those uncertainties decrease as they are aggregated assumes a lack of correlation, and is therefore invalid.

No. It assumes a lack of total correlation. Many of these factors will be partially correlated, but the ways in which they are correlated are not always obvious. More people means more resource depletion, pressure on land, water, etc. But it also means more hands to work, more minds to think, more potential problem-solvers. The problem can sometimes contain elements of the solution.

A concrete example of this: China. As China becomes richer, it also consumes far more resources. The rise of a consumer class in China puts all kinds of strains on the world's ecosystem. But, China is now a world-leader in research into alternative energy. It is a world-leader in research into quantum computing and many other fields too. The industrialisation of China has unleashed an enormous creative energy that was not there before.

 

[Falcon]

No. It assumes a lack of total correlation. Many of these factors will be partially correlated, but the ways in which they are correlated are not always obvious.

True. Non of which supports FS assertion that uncertainty *necessarily* reduces with increasing factors.

More people means more resource depletion, pressure on land, water, etc. But it also means more hands to work, more minds to think, more potential problem-solvers. The problem can sometimes contain elements of the solution.

True. But not all factors are equal. I can readily concede that lots of unthinking, bad problem solvers could still eke out a comfortable existence in lush pasture. I cannot concede that lots of thoughtful problem solvers can necessarily do so in soil-less, sterilised, waterless, pestiferous desert.