Saturday, February 02, 2013

The Bitch Always Gets Her Money Back

Hoisted from the comments, Bernard J muses

There's an ecological principle that about 10% of photosynthetically-captured energy passes from one trophic level to the next hight one. So of a million joules of shiney sunshine captured by lettuce, ~ a hundred thousand will fuel caterpillars, ten thousand will fuel chickens, and one thousand will fuel humans... with any degree of sustainability. Of course it's more complicated than that (including the presence of more trophic levels than I describe) but you get the general idea.

Consider that humans are currently sucking about 550 exajoules per annum:

and that annual photosynthetic energy capture is apparently around ten times this value:

For a species that exists at the apex of the trophic pyramid to co-opt such a disproportionate amount of energy is simply thermodynamically unstable. This is not to say that the energy must comes from the biosphere, now or in the future (obviously we're sucking moat of it from the last three hundred millions years or so of photosynthetic banking), but its expenditure during human activity is inextricably linked to the overall entropic state of the biosphere.

And as I said recently on another Rabbet Run thread, thermodynamics is a bitch. There's simply no way that a huge proportion of the sand in the sandpit can be stacked grain upon grain upon grain in one corner. Other civilisations found this out in the past: our turn is coming, with much of the thermodynamic debt to be paid by the agency of extinction - if not of our species, then by many others, both floral and faunal.

Thermodynamics/entropy imply an asymptote that defines maximum sustainable human energy use, no matter the source of the energy. Overdraw, and the excess will be paid with high interest.

And the bitch always gets her money back.

It's a lesson that too few understand, even amongst the scientific fraternity.

31 comments:

Anonymous said...

Speaking of being overdrawn, have you seen the latest nonsense on the Nature editorial page? I get the feeling they're outsourcing this stuff from TransCanada's PR department.

Anonymous said...

"Nature's Wisdom"
(In a Nutshell)
– by Horatio Algeranon

To earn the sacred trust
Of CFOil and crank
Obama simply must
Open Keystone Bank

Hugh Laue said...

YES!!!!

Well, as Richard Heinberg says see www.postcatbon.org, there are no solutions,
only more or less appropriate responses. Permaculture Design (as
per Moillison, Holmgren, Lawton,
etc) is proving to be the most
appropriate one for the crisis
facing humanity's survival (climate
disruption, peaking fossil fuels
AND many other resources, an
economic system disconnected from
biophysical reality and the end of
growth as defined by that system).
The empirical evidence is
overwhelming see
http://www.geofflawton.com/sq/15449-geoff-lawton
And yes, my son qualified as a PD
end 2011 and together we are
transforming our garden and he's
got projects going at two schools
in our (very) disadvantaged
townships here in Port Elizabeth,
South Africa. I visit Real
Climate, Climate Progress, Tamino,
Eli, wunderground (Jeff) on an
almost daily basis - so much so
that I feel part of a family!! :)
Stuart Hill says this is not a
political problem - it's a
psychological -social problem. I
agree - it's a question of values
and raising of consciousness.
Thanks, Hugh

Tom Curtis said...

Bernard J compares total industrial energy consumption, not food energy consumption, by humans to photosynthetic energy production. That is an inappropriate comparison because we do not, and cannot, fuel our industrial energy requirements from biofuel alone. Nobody imagines that we could.

Rather plans of renewable energy production are based on direct solar power, indirect power from the wind (which is partly powered from the sun, and partly from the Earth's rotation), indirect wind power in the form of wave power, tidal power (indirectly driven from the Earth's rotation), and geothermal power. That is assuming we preclude direct fission energy as a source of power, and are never able to harness fusion to power our generators.

Further, even the direct solar power is not necessarily a substitute for photosynthetic production because it is not limited to the 10% efficiency of photosynthesis, and can be sited in deserts where little photosynthesis occurs. Further, even biomass used to power industrial energy (including transport) is not necessarily limited to the 10% efficiency given by the ecological rule.

As it happens, the total solar energy striking the earth is around 5.5*10^24 Joules per annum, while human industrial energy use is around one 10 thousandth of that value. Even limited to 10% efficiency, and ignoring non-solar sources of energy we face no limiting constraints on energy use in the immediate future. Neither limitation, of course, applies.

Far more disturbing is that human energy consumption as food (2.4*10^20 Joules) is one 18th of total Net Energy Production by photosynthesis (2.4*10^20 Joules). Contrary to Bernard J, the majority of human energy consumption as food is from plant material, ie, at one trophic level. That means Humans monopolize around 56% of the carrying capacity of photosynthesis in terms of animal life. The exact figure is difficult to determine in that a significant portion of human food energy comes from meat, at two trophic levels, or apex predators among fish (tuna) at three or four trophic levels. On the other hand, human industrial processing results in far greater than the standard 10% being available, both by reuse of waste and by breeding for increased digestibility/energy content in foods.

In all, it is estimated that 38% of NPP is diverted for human use. That must rapidly be approaching an unsustainable amount.

Russell Seitz said...

Swallowing the 38% NPP revives the ideoogically divisive debate as to wether 'agriculture ' is more or less productive than natural ecosystems.

Please correct my recollection, but is it not the case that a couple of decades ago the low side cohort , including Ehrlich, focused on slash and burn crops and excluded GMO's and modern monocultures, while subsequent studies including them have drawn the opposite conclusion?

David B. Benson said...

Well, there is quite a bit of uranium. Even more in sea water.

Anonymous said...

[Part I]

"Bernard J compares total industrial energy consumption, not food energy consumption, by humans to photosynthetic energy production. That is an inappropriate comparison because we do not, and cannot, fuel our industrial energy requirements from biofuel alone. Nobody imagines that we could. "

Tom, I think that you're missing the point in this regard.

I didn't say that we could or were fuelling our activities from photosynthetic capture. To the contrary, I noted this in my comment:

"This is not to say that the energy must comes from the biosphere, now or in the future (obviously we're sucking mo[s]t of it from the last three hundred millions years or so of photosynthetic banking)"

The problem is that our use of energy spills over into our interactions with the biosphere, regardless of whether or not we are sourcing non-metabolic energy from it. Again, this was noted in my comment:

"...but its expenditure during human activity is inextricably linked to the overall entropic state of the biosphere."

The reference to primary photosynthetic productivity was firstly for context, especially with respect to the trophic relationships between taxa, and humanity's unique place at the apex. Whatever the source of our non-metabolic energy, we are heavily and inextricably linked to the biosphere for food and it serves us ill to forget how we are placed in the web. There is also the secondary and no-less-important fact that we rely inescapably on the biosphere for many other ecosystem services.

At the most essential consideration it's almost irrelevant whether we derive our non-metabolic energy from the biosphere or not. It is important though to understand what our energy use is, because that total is a good proxy for how we impact on the biosphere that sustains us. There is a strong correlation between total human energy use and the requirement for extraction of biospheric resources. At its most basic this relates to human numbers, and to the fact that human activity heavily reflects expression of Jevon's paradox, where any efficiency in a process simply results in expansion of activity to maximise the space available. This also reflects the fact that almost all human activity occurs within the biosphere, so the more active (energised) we are, the more we impact the biosphere. We are not partitioned from the global ecosystem.


Bernard J.

Anonymous said...

[Part II]

Energy expenditure reflects entropic increase. Human energy use overwhelmingly simplifies the ecosystems in which it occurs, which is effectively a reflection of entropy increase. Whether mainfested as co-option of net primary productivity or as damage to the health of ecosystems and the species within them, the more total human energy use increases on Earth, the more we damage the Earth's living systems. Extinction, loss of ecosystem function and resilience... these are a loss of information/increased simplicity/exacerbated entropy increase.

Life on Earth (and on any planet) is bounded within a thermodynamic 'space' by four dimensions of space and time, and by the energy input into that 'space'. Within that 'space' life has optimised the complexity: entropy ratio. Fossil fuels, as reduced or semi-reduced carbon, could be regarded as sources of slowly-accumulated 'negative entropy' as much as they are of energy. When we exploit that fossilised energy we are 'releasing' in a short period of time entropy into a system that it not designed to cope with it with respect to the aforementioned opimisation of complexity-for-entropy. Nuclear and renewables are not much different - and the more the apportioning through human activity relative to the total thermodynamic bound increases, the more the natural system pays the thermodynamic debt.

No matter the attempts at rationalisation, human energy use with the current rate of population increase, and at the level of contemporary high technology and its rate of progression, are occurring in a finite thermodynamic space. Imagining otherwise is akin to imagining perpetual motion, and it's just these sort of imaginings by many otherwise intelligent professionals that is resulting in entropic overtures such as the recent global financial crisis, increasing extinction, and indeed climate change.

And it's not a matter of solving just one or two problems. That's the thermodynamic equivalent of shifting the gridlock to the end of the new section of highway.

If humans can't attend to the thermodynamic overdraught, the bitch will.


Bernard J.

Hank Roberts said...

Op. cit.

Flakmeister said...

Re: the Fermi Paradox, I am starting to wonder whether a planet which has sufficent C02 to have oceans remain liquid though most of its middle age while the host star is cooler is doomed when a when/if species becames capable of unlocking all that sequestered carbon...

Anonymous said...

"Human energy use overwhelmingly simplifies the ecosystems in which it occurs, which is effectively a reflection of entropy increase."

yes, human-produced "pollution" == entropy increase

Jeremy Rifkin wrote a book about this long long ago (1980) entitled "Entropy".

All animals increase the entropy of their surroundings to keep themselves far from equilibrium.

But we are the only animal that produces crap (quite literally) that can't be recycled by the other animals and plants within the biosphere.


If we are to survive, we need to have a completely new approach not only to the amount of energy we use (we need to use less), but also of how we use that energy. Our "end product" needs to be recyclable (either by ourselves or by the other life in the biosphere) -- and recycled.

Human activities essentially amount to a "life line" (which terminates in a dead end) when true "sustainability" requires a "life cycle".

~@:>

Holly Stick said...

And probably we will have various disasters piled on each other. Like the collapse of the salmon and/or a salmon virus that mutates to affect humans:

http://www.thestar.com/news/canada/2013/02/01/infected_salmon_declared_fit_for_human_consumption_by_canadian_food_inspection_agency.html

Jim Eager said...

Tom Curtis wrote "we do not, and cannot, fuel our industrial energy requirements from biofuel alone."

The fact that we already do exactly that escapes you.
What, exactly, do you think fossil carbon fuels are?

Russell Seitz said...

" we are the only animal that produces crap (quite literally) that can't be recycled by the other animals and plants within the biosphere."


Rifkin seems to enjoy an exception to this rule.

EliRabett said...

Until about 200 years ago recent photosynthetic activity WAS the source of all energy and food. If you want to push the analogy, fossil fuels gave us access to banked photosynthetic activity, but the bank is calling the loans due.

Anonymous said...

Russell,

That's an interesting statement, though not particularly enlightening (other than to indicate that you think Rifkin's stuff is rubbish)

Perhaps you would like to elaborate a bit.

But to the point of what I was referring to:

Do you disagree with Rifkin's claim that human-produced "pollution" is a manifestation of entropy increase? (the same point Bernard also made, unless I have somehow misunderstood)


Quite frankly, it was so long ago that I read Rifkin's book (soon after it came out) that I can't even remember the other points he made (to say whether they were valid from a physics standpoint, for example)


~@:>

Anonymous said...

~@:> mentions Jeremy Rivkin's book 'Entropy', which I'd not previously heard of. Definitely something for me to track down.

Thanks for the pointer!


Bernard J.

Hank Roberts said...

I think we're going to have to risk radioactive gray goo, myself.

http://www.sciencedirect.com/science/article/pii/S0079670009001051

kT said...

There is a lot of modern stuff around on entropy, even an entire journal devoted to it, but I am still particularly fond of James Kay's ramblings on the subject, and his mathematical exposition was particularly succinct. Unfortunately he is gone now and most of the more important papers are gone from the University of Western Ontario server.

To understand it completely you have to work Fermi and Bose statistics into the framework. There are also important issues in cosmological physics that can best be approached using analogies in condensed matter physics.

Weirdness is coming, trust me. Possibly not in time to help us out of this problem, but some innovative solutions are there.

kT said...

the bank is calling the loans due

Worse than that, we are biological creatures trying to go borg.

Ain't gonna work unless you assimilate the plants as well.

Russell Seitz said...

Slow grind the mills of the Gods, but photosynthetic activity does not much figure in their hydropower supply , or for that matter , exothermic nucleosynthesis in the sun.

Algeny is a fairly cranky piece of work- it registered when glanced at a generation ago as sort of Gaia lite.

Anonymous said...

Well, Russell, I don't even recall bringing up the book "Algeny" in my comment (I've never read it or even heard of it), but I'll have to re-check to make sure.

That "Algeny" might have been "cranky" is really neither here nor there as far as my comment was concerned.

"Entropy" is the focus and my comment was actually with reference to Rifkin's thoughts about pollution as entropy increase.

While that equation may not seem particularly extraordinary now (except perhaps to mainstream economists), it actually seemed pretty astute back when Rifkin made it.

Whatever else Rifkin might have thought (about this that and the other) really makes no difference to me one way or the other.

In my opinion, the vast majority of what economists (particularly mainstream ones) say about physics, biology and ecology* (if they indeed say anything at all) is gibberish, but that does not mean they don't say meaningful and useful- things now and again.


~@:>

Ron Broberg said...

Some sketches on this theme from last summer:
http://rhinohide.wordpress.com/2012/06/16/a-few-quick-global-energy-stats/

Dave said...

Meh. There's tens of thousands of years of fissionables, maybe millions of years of fusionables at current usage rates. Other civilizations collapsed because elites used force to set up economically extractive institutions and crushed anything that might threaten them, and eventually they always collapsed in the fight over who got to be elite. Since 1688 the paradigm of "screw the elites, let's allow creative destruction that threatens them!" has become dominant, at least in the West.

It also may shock and horrify people to say this, but Man could reorganize/reengineer life on this planet on a massive scale to serve us a lot better than lettuce does (and we use, what, 1-2% of current inferior biomass? feh!). Not saying that's desirable, mind you, just that it's possible.

Jeffrey Davis said...

"Since 1688 the paradigm of 'screw the elites, let's allow creative destruction that threatens them!' has become dominant, at least in the West."

Earth to Dave! Earth to Dave! Come in, please.

Dave said...

Oh, sorry, did you miss the Industrial Revolution? Maybe they don't teach that anymore. Probably not your fault.

kT said...

There are several billions of years of fusionable left, Dave, the fissionables are primordial. No, wait the fusionable is third generation primordial and the fissionables are cosmogenic.

Where does your food come from? Oxygen? Where does the carbon dioxide go? Water? Warmth?

And you want radioactive borg?

-n said...

While the elites in charge of economically extractive institutions are no longer strictly limited to those with lots of pointy sticks, it is silly to claim that they are either being screwed or threatened by "creative destruction."

Beyond silly, it is downright foolish to claim that these new economically extractive institutions are not capable of bringing about collapse.

kT said...

In the future, carbon dioxide must become subject to extraction and fixation technologies.

Mal Adapted said...

Dave reminds me of my favorite metaphor for over-confidence in technology is the sorcerer's apprentice. Any attempt to "reorganize/reengineer life on this planet on a massive scale to serve us a lot better" should only be attempted if there's an old, wise sorcerer available to save us from ourselves.

KAP said...

I strongly recommend to you Garrett 2011, "Are there basic physical constraints on anthropogenic emissions of carbon dioxide?", Climatic Change 104:437:455 which examines the thermodynamics of civilization as a whole. It makes frightening (and enlightening) reading.