Earth as a magic pudding

Guest post by Dr Michael Lardelli


Cornucopians – those who believe the Earth’s resources are boundless – have a clever mental trick to avoid acknowledging that the planet is finite. It is commonly called the “resource pyramid”.

The argument goes like this. When we first begin to extract a substance from a resource we exploit that resource in which the substance is most concentrated (and so easiest to purify) and/or most accessible.

An example of this would be digging large gold nuggets out of riverbanks in the Victorian goldfields in the 1850s or mining phosphate-rich guano on the Pacific island of Nauru by simply scooping it up and bagging it. However, as you probably know, the alluvial gold of Victoria and the guano on Nauru were both mined out many years ago.

You might think that this would lead to a severe shortage of these materials but this is where the resource pyramid works it magic. As these resources begin to become scarce their price rises. The higher price now makes it economically viable to extract the substance from a less accessible and/or less concentrated source. Amazingly, the total amount of the substance present in this lower-grade resource is greater than in the original, most concentrated resource. This pattern repeats. As the less concentrated resource begins to be mined out the price of the substance rises ever higher so that extracting it from an even lower grade/less accessible source becomes economically viable.

The total amount of the substance present in the lowest grade of resource is greater than previously. By this argument we can never run out of a substance because the more we use, the more becomes economically viable to extract. Our planet truly is a magic pudding! This idea can be represented as a pyramid with the small amount of most concentrated/accessible substance at the top and successively larger amounts of the substance in lower grades of ore, and so on, as we move down:

The resource pyramid idea contains a hidden assumption – that energy is cheap and abundant. In fact, it is the price of energy that ultimately determines the base of the resource pyramid. At each step down the resource pyramid the substance sought is less pure and/or accessible and so it requires more energy to extract.

At some point the cost of the energy required to exploit the resource will equal the value of the substance obtained. It is at that moment that exploitation of the resource ends. To date, energy has been so cheap that we have rarely (if at all) been faced with having to end exploitation. (No examples spring to my mind. Maybe readers can suggest some in comments on this article.) The high price of any substance has usually resulted in substitution by something else more abundant.

When it comes to discussions of oil or other energy sources Cornucopians apply the resource pyramid argument in one form or another. The following comment by the CEO of Exxon Mobil Australia is a good example:

According to the US Geological Survey (USGS), the Earth currently has more than 3 trillion barrels of conventional recoverable resource and so far we’ve produced 1 trillion of that. Conservative estimates of heavy oil and shale oil push the total recoverable resource to over four trillion barrels.

And more recently, the chief economist of BP said:

Therefore there will never be a moment when the world runs out of oil because there will always be a price at which the last drop of oil can clear the market. And you can turn anything into oil if you are willing to pay the financial and environmental price.

This contrasts with those convinced that a peak of oil production is imminent who mostly believe that only about 1 trillion barrels of extractable conventional oil remain. (Note – it is worthwhile remembering that the peak oil concept is about the rate of oil extraction, not the total extractable reserves remaining.)

What the Cornucopians do not seem to understand is that energy must be invested to produce energy. If hydrocarbons are being mined for energy then exploration must occur, wells must be drilled, the oil or gas must be extracted and separated into various fuel grades before further distribution to vehicular fuel tanks. (The process is much more complicated than this but you get the general idea.) It is an energy intensive process.

Earlier in the Oil Age when the most easily accessible oil fields were first tapped a relatively small energy investment gave a huge energy profit – by some estimates a profit ratio of 100-fold or greater.

As oil extraction from a field proceeds the pressure drops requiring more and more energy-intensive methods to be used to continue the extraction – such as pumping down gas or water to maintain pressure and/or pumping up the oil. Also, as the Oil Age has proceeded the size/accessibility of oil fields discovered has decreased (since larger and more accessible fields are easier to find and so are found first) and the more intensive exploration and drilling required to exploit the smaller/less accessible oil fields requires more energy.

If we begin to exploit non-conventional sources of oil then the energy inputs required are greater still, meaning that the net energy produced from each energy unit invested decreases. What this means is that as we use up our highest quality/most accessible hydrocarbon resources and begin to consume lower quality/less accessible resources, the net energy produced from each unit invested decreases.

If the object of the mining activity is net energy production (i.e. the actual energy left over after the inputs to mining, processing and distributing it have been subtracted) then the volume of net energy decreases as the resource quality declines, i.e. as we move down the resource “pyramid”.

In fact, the resource pyramid for net energy resembles more a pyramid standing on its apex! This is shown in the figure below where EROEI is the acronym for Energy Returned on Energy Invested. Once net energy production from the extraction process falls to zero (i.e. EROEI = 1) then it is impossible for the activity to continue (unless the activity is subsidised with energy from another source).

It is true that the world possesses hydrocarbon resources equivalent to many trillions of barrels of oil but these will never be harvested for energy production. It may be that they will be mined, for example, for plastics production at some future date but the energy to do the mining will come from elsewhere.

Many readers may believe that technology will solve this net energy problem by providing less energy intensive methods to extract hydrocarbons from difficult resources. While technology can have a marginal impact, there are some minimum levels of energy investment that cannot be circumvented. For example, the molecular forces holding oil within its constraining rock matrix will always require a certain minimum application of energy to overcome and nothing can magically levitate oil at low pressure up from a deposit several kilometres below ground.

Even if all the low quality hydrocarbon resources could be exploited, the rate at which these difficult deposits could be mined would be low and so would be the rate at which we could obtain energy from them.

The ultimate consequence is that, at some point (“peak net energy”) the rate at which we will obtain energy from fossil sources must decline. An interesting example of this is energy production from coal in the USA. While the tonnage of coal mined in the USA is now at record levels, coal quality is declining and the total energy content of the coal has been decreasing since 1998 (PDF 534KB)!

Also, the total rate of oil production is currently on a plateau and may have peaked but we know that the best grades of oil requiring least processing for gasoline/petrol production (“light sweet crude”) peaked by 2004 and that new oil production is increasingly “heavy and sour”. This, combined with the additional energy required to exploit smaller and more remote oil fields means that we must be at, or close to, the peak rate of net energy production from oil.

The resource pyramid is an interesting concept that allows economists to argue that resources are unlimited. However, like so much economic theory, it is only an illusion supported by cheap and abundant energy.

Note: Factors influencing the resource pyramid concept are discussed in detail in a 2002 article in Geotimes. The authors place great significance on advancement of technology for increasing resource availability but they never mention net energy.

Michael Lardelli is Senior Lecturer in Genetics at The University of Adelaide. Since 2004 he has been an activist for spreading awareness on the impact of energy decline resulting from oil depletion.

The article also appears at Online Opinion. This work is licensed under a Creative Commons License.



  1. Interesting to compare this post with food production. I know sweet fa about shale oil, but I imagine it’s like aquaculture which turns unfashionable fish
    into fashionable fish, but is a huge net consumer of fish. It could be
    profitable to burn coal to produce energy to transform shale oil into
    “normal” oil because normal oil is a more desirable product than coal.


  2. I am graphically reminded of the substantial truth of this post every time I visit my scrap metal yard. While I may harbour some resentment at the ‘bludging’ role of this middleman, I don’t blame him for the (IMHO) obvious distortions in the recycling market of base metals. Aluminium is the most obvious. We know that recycled aluminium under various labels – cans, extrusions, spun – takes about one tenth of the energy to re-make it into new aluminium products when compared with raw bauxite. Why then does it return to the vendor (in NSW) less than $1.50 per kilogram. If payment were based on the energy consumed then the refiners – via the middlemen – ought to be paying 3 – 5 times for aluminium scrap. I could go on. My last visit at the end of October witnessed a huge decline in going rates being offered, so much so that my middleman had posted an apology to customers at the gate.
    An example. Ferrous metal – iron/steel – is currently fetching $20 a tonne or 2 cents a kilo. A month prior it was at $100/tonne. Kevin Rudd ought to be concerned at the lack of incentive, nay demoralisation of the recycling industry in the current economy. If it is good enough to put a floor under the banks then we recyclers await his intervention. We’re ready to stockpile.


  3. Check (carefully) the link(s) behind the “Josh Maxwell” name above.
    Looks like a search engine optimizer/blogspammer site, superficially convincing because it collects related terms, but under that is crap stuff.

    [Thanks Hank, it slipped through the SPAM filter – now deleted]


  4. One aspect that modifies this to some extent is the portability and concentration of energy. In the absence of significant improvements in battery technology, I could imagine it being worthwhile to, say, have a large field of solar cells powering a very low-grade extraction of oil even if the EROEI was a bit less than one, due to the transportability of oil vs batteries. But this is admittedly pretty hypothetical.


  5. Indeed, James Haughton @4, I’ve often wondered if anyone has looked at using a direct solar thermal mechanism to retort oil shales and sands. This might reduce the impact of what is otherwise one of the most heinous climate nasties.


  6. Many years ago when Eli was a bunny he read an article in Scientific American about resource extraction. Turns out that the pyramid has exponentially decreasing sides. That means that the quality of the ore decreases exponentially which means that the amount of energy needed to extract the ore increases exponentially (roughly, better methods will have an effect).

    alt.environment had this discussion with John McCarthy of LISP fame. He set the cost of energy to a faith based zero to open the cornecopia


  7. This is an area where the Green Left doesn’t know what the Green Right is doing. What the author says is correct: future energy will come at an increasing cost, and in turn lead to reduced consumption; the economic models behind climate change scenarios ignore this and assume that growth in energy production will continue unabated. For example Nicholas Stern who did a detailed review for the British Government says”
    “Increasing scarcity of fossil fuels alone will not stop emissions growth in time. The stocks of hydrocarbons that are profitable to extract (under current policies) are more than enough to take the world to levels of CO2 concentrations well beyond 750ppm, with very dangerous consequences for climate-change impacts.”


  8. > inexpensive
    Still limited by available biomass, even if it’s not symbiotic with some enzyme system of the particular tree it was found in. We’re already using more than our share of the planet, if we want to keep the rest of the living world.


  9. Another kind of pyramid……a colossal economic pyramid scheme.

    Billions of dollars in bailouts and year-end bonuses are being directed to the “wonder boys” on Wall Street. These self-proclaimed Masters of the Universe have turned a great capitalist system into a paltry gambling casino. In the light of all their greedy risk-taking and conspicuously hoarding behavior, they can no longer be called by any name other than “thieves of the highest order”.

    Steven Earl Salmony
    AWAREness Campaign on The Human Population,
    established 2001


  10. As an ecologist one of my growing fears is that humanity somehow does find a cheap (and yes, even renewable) source(s) of energy with which to tap the cornucopian pyramid because, as Hank Roberts alluded to at #9, the biosphere is already overstretched. And unfortunately for the biosphere, whilst it has the capacity for regeneration up to a rate-limited point, it is nevertheless finite in its physical bounds, the magical thinking of ‘growthers’ notwithstanding.

    If the day comes where we can fuel trucks and ships with reliability over extended periods of time, how long before the last of the world’s forests, fisheries and other ecosystems/services are exploited to extinction? What mechanism(s) are currently proposed or are in train to insure against such eventualities? None that I can see that are succeeding in the present…

    On a tangent to this and to the thrust of Michael Lardelli’s piece, I sometimes have debates with a certain subset of ‘growthers’ who subscribe to the particularly magical thinking that we can/will colonise space, and that this will be humanity’s salvation (besides being its manifest destiny). My simple questions for them are:

    1) how much energy is required to take 10 people to the nearest habitable planet to live there for one year?

    2) how much energy is required to take 100 people to the nearest habitable planet to live there for ten years?

    3) how much energy is required to take 1000 people to the nearest habitable planet to live there for 100 years?

    4) oops, if the nearest few planets are not habitable, how much energy will be required to make at least one of them so?

    5) how much energy will be required to move all of the biosphere and humanity that is/will be endangered by our current trajectory on this planet, to another suitable planet?

    6) how do these energy budgets compare with our current energy expenditures to toss a few people and accompanying bits and bobs into near-earth orbit?

    7) where is the difference in energy requirement going to come from, and how does our trajectory to achieving fulfillment of this difference compare with the trajectory of damage to the biosphere upon which we currently rely?

    8) where in the calculations of these energy budget are the risks of increasing complexity that accompanies increasing technological sophistication, and of diminishing returns that accompanies the same, factored?

    This list can be easily added to, but in the end, whether it is a consideration of fossil energy use, biospheric exploitation or utopian space exploration, the secret ingredient upon which all proponents seem to rely is the eponymous magic pudding of this thread.

    And we all know how that model has worked in the current financial kitchen…


  11. Bernard @11, I suspect that the answers to 1), 2) and 3) will end up being pretty similar, for the reason that beyond a certain number of person-years (probably exceeded by your scenario 2) and certainly 3)) any such colony would be self-sustaining, and the lifetime energy budget would end up comfortably exceeding the energy cost of getting there. On that score, and in answer to 6), the aphorism ‘once you’re in Earth orbit, you’re half way to anywhere in the Solar System’ is not a bad approximation.

    One answer to 5) that would involve nothing like the amount of energy you’re thinking of: Seedships.

    As for 8), well, that’s just out-and-out technophobia. Try Damien Broderick’s The Spike for an antidote.


  12. Sorry, but re me @12, forgot to mention – the eponymous magic pudding is not required, but the big bright thing in the sky may well have something to do with it. And hydrogen, deuterium and uranium aren’t only found on Earth.

    Only one thing is certain – that the course advocated by Bernard will result in the extinction of everyone and everything. I prefer to seek alternatives.


  13. Mark Duffet.

    I appreciate your enthusiasm for technological magic, but you need to back up your optimism with some serious numbers if you are going to make a concrete case. “Probably” and “certainly” don’t mean anything in practical terms, and “half-way to anywhere” is half-way to no-where in the context of justification.

    I’m a rabid fan of science fiction and of the future possibilities of science, and I am certainly no technophobe: my early adoption of most every technology is testament to that. However I’ve also been a practising scientist for over two decades and I have some acquaintance with the progress of the technologies that science has generated, and also with the lack of progress in technology that has also occurred. I say this with the smugness of having predicted (over countless Friday night beers with colleagues) just about the entire progress of biotechnology over the last 20 years – as well as the lack thereof.

    There is a degree of predictability to technological progress, and the naïve monotonic projections of many futurists/technomaniacs fail to take account of fundamental limitations imposed by thermodynamics, by resource availability, or by integrated systems functioning and complexity, whether such systems are physiological, ecological or technological.

    If we can’t maintain the unique biosphere on Earth, which evolution has fine-tuned over millions of years of mind-boggling ‘experimentation’, how are we going to construct, commission and maintain a robust biosphere elsewhere in the span of a generation or two? In fact, can you name any demonstration on Earth of the proof of concept where a completely self-contained ecosystem has maintained a human ‘colony’ for effective indefinite periods? The Biosphere experiments in the US have been less than impressive, and this is with the global ecosystem a mere glass-pane thickness away from such adventures.

    And even if it were possible to somehow send a self-sustaining ecosystem into the cosmos, and have it survive thousands (if not millions) of years of intervening travel without terminal equipment/robotic caretaker/propulsion/navigation failure, any such shipload is completely irrelevant to the overwhelmingly vast majority of humans, and indeed of other species, on planet Earth. They will still be faced with the same outlook as before if the addressing of the integrity of our planet’s biosphere is avoided.

    For all practical purposes it is utterly irrelevant to any of us whatever might be sent into space – our survival and our descendants’ survival are intrinsically and irrevocably tied to the survival of the Earth’s biosphere.

    The interstellar future envisaged by the starry-eyed futurists and growth-economists is a model akin to neoplasty, and neoplastic growth is never perpetually sustainable. Ask anyone who has worked in oncology or in ecology.

    It could be quite reasonably argued that the extrapolation of the expansionist model of progress to its end-point is one that would ultimately end up producing a Borg-like culture. This begs several questions including: is this desirable, is this energetically sustainable, and if it is even possible why hasn’t such a culture evolved elsewhere in this rather old universe and already taken us over?

    One could argue for the possibility of other scenarios, but in any expansionist case the fundamental limitations imposed by cultural complexity and attendant risk of failure, by sustained profound energy requirement, and by other limits to monotonic growth need to be seriously elucidated.

    Sure, the sun is a huge source of energy, but so far the planet has pretty much perfected the capacity for biospheric harvest of its energy. Any additional harvesting of solar energy on earth is not likely to be exportable to extraplanetary locations, and beyond a Mars orbit the capacity to collect colonisation-usable quantities of solar energy has yet to be demonstrated. Uranium, thorium, fusion? None of these have yet offered the energy density required to move humans beyond the planet, let alone the solar system.

    Any serious possibility of an extra-Earth colony can really only be focussed on Mars in this solar system, and even that option is tenuous compared with maintaining our current habitable planet. Mars has a much lower gravity, and attendant to this is the past loss of much of its water: water that we take for granted here on Earth. Sure, there are ways to ration extra-Earth water, or extra-Earth oxygen, or any of a myriad of other extra-Earth resources we take for granted on this planet, but they are all a ‘step down’ (at the very least) compared with what we have access to here. To think that we can expand across the universe under this scenario, even ignoring the flabbergasting energy budgets that would be required to utilise such resources, is to put many carts before a rather naggy and flea-bitten horse.

    As to the possibility of true interstellar travel… well, short of stumbling upon di-lithium crystals, worm holes and stasis capsules, I think that we are pretty much stuck on this block. Science fiction is one thing, science fantasy is a different kettle of fish altogether.

    Personally, I think the best thing that we could do is send all the futurists to the moon with ten years worth of supplies (a hundred if you’re feeling generous), tell them to work it out themselves and don’t come back, and then get on with the job of proper maintenance of the only spacecraft that our biosphere is ever going to have – planet Earth.

    If this advocacy dooms all life on earth to extinction, then such a conclusion is rather semantic in the end. Given the time scales for such to occur it is irrelevant to the argument, because the evolution of the universe will ensure extinction of life irrespective of where we hang our hats, and in pretty much the same order of time-frame magnitude.

    And for what it’s worth, I seriously doubt that all life on earth is vulnerable to extinction by simple consequence of humanity’s inability to expand beyond the solar system – we might shit in our own nest and wipe ourselves and a nice swag of collateral species out in the process, but life and evolution will carry on regardless. It’s happened before and it will happen again, our fear of mortality notwithstanding.

    Our unique opportunity, at least for the next aeon or two, is to manage our ecology and evolution not by genetic engineering and/or by cybernetics, but by informed and nuanced management of the processes that gave life to our species in the first place. Perhaps beyond this time we will develop a sophistication of physical understanding that will allow us a further reach, but given our current trajectory of technological development compared with that required to realise the dreams of futurists, there is a gap that no-one seems to be sensibly able to account for.

    I know all about (certain) science fiction materialising into science fact, but by extension the fictions of fairytales hundreds of years ago could have equally validly materialised by now. I am still waiting for my spell book to produce a levitation cantrip though, and those damned fairies are as elusive as they were in the middle-ages.

    I too prefer to seek ‘alternatives’, but how about we start with the sensible and practical ones first, and leave the fantasy as luxury backup rather than an extreme-risk first-line gamble?


  14. Re Bernard @11 & 14.

    For the sake of the argument I’ll take out the ‘probably’ qualification: any such expedition/colony WILL have to be locally sustained, so the question of Earth-derived energy consumption with regard to duration does not arise. That just leaves transport. For Mars:

    scenario 1) 3 x 10^11 J

    2) 3 x 10^12 J

    3) 3 x 10^13 J

    On a very pessimistic approximation of my last electricity bill, that’s about A$1640 per person. A worthwhile investment to safeguard the survival of the species, I reckon.

    Uranium, thorium, fusion? None of these have yet offered the energy density required to move humans beyond the planet, let alone the solar system.

    Actually, they have, though it’s a bit messy.

    fundamental limitations imposed by…integrated systems functioning and complexity

    not by genetic engineering and/or by cybernetics…

    This still sounds like technophobia to me. ‘Fundamental’ is a very big statement. You must have read a book or three that I haven’t. The only other person I’ve heard come out with similar-sounding overwrought pessimism is the ridiculous Jeff Goldblum character in Jurassic Park and its sequel. The implication of Broderick’s (non-fiction) work is exponential development in control capabilities to match and indeed outstrip ‘increased systems complexity’.

    …the evolution of the universe will ensure extinction of life irrespective of where we hang our hats, and in pretty much the same order of time-frame magnitude.

    “Pretty much the same”? I don’t think so; I think our galaxy is good for quite a few more stellar generations and associated red dwarves yet; I’d back the latter to be around at least several orders of magnitude longer than Sol. Worth a shot, I reckon. Over that sort of time, literally just about anything is possible – unless of course we don’t try.


  15. Perhaps it is time for the same ol’ business-as-usual, pin-stripe-suited leaders, the ones who adamantly espouse and religiously exemplify an apostate’s creed of greed, to be replaced by new leadership.

    Too many leaders of this patently unsustainable culture of avarice evidently define the culture’s efficacy by the endless accumulation of material possessions; by the unbounded acquisition of more money, money, money, money; by recklessly overconsuming and relentlessly hoarding limited resources. They demonstrably declare to all the world that greed is good.

    Are we not members of a culture that worships consumerism? Are the products of greed nothing more or less than the objects of our idolatry?

    Are the pin-striped suits, fleet of cars, chauffeur, private jets, McMansions, distant hideaways, secret handshakes and exclusive clubs…… all “signatures” of success in a culture promoted by the ‘goodness’ of greed?

    Consider for a moment what perversity greed has wrought.

    Steven Earl Salmony
    AWAREness Campaign on The Human Population,
    established 2001


  16. Mark Duffet.

    OK, let’s just consider the Mars example.

    Exactly where is the colony/expendition going to obtain its on-planet energy?

    Or, to break this down a little, how much start-up energy is required to locate the new energy source? How much start-up energy is required to harvest the new energy source? How much energy is required for miscellaneous infrastructure associated with energy-delivery?

    Associated with these questions are the further questions:

    What start-up non-energy resources are required to establish the expedition/colony? How much energy is required to harvest these non-energy sources? How much energy is required for miscellaneous infrastructure associated with non-energy resource-delivery?

    These questions above are predicated on the necessary assumption, which you acknowledge yourself, that the adventure is not depending on Earth for resource sustenance.

    What is the breakdown of the energy budgets that you quote? Do these budgets account for all reasonably predictable contingencies, or are they just physical estimations of the energy required to move x kg mass over y km of space? Where is the evidence that the “A$1640 per person” cost you quote for such transport cost applies to any space-travel fuel? After all, it seems to be costing us a little more than that per person to send a couple of people into the relatively low orbit occupied by the International Space Station. If you have a cheaper option NASA, ESA, et al should be beating a path to your door.

    How do the above questions relate to travel to Mars (which is the only feasible solar system destination) in the fanciful concept of ‘Seedships’? How do the questions above, including the last one about Seedships, relate to an excursion to the nearest extra-solar inhabitable planet, including the resource and energy cost of finding such a location?

    Where is the proof of concept that such an undertaking can be done without a high probability of failure?

    With respect to Project Orion, which I first read about 30 years ago, where is the evidence that we can reliably put this conceptual technology into practice without a reasonably probability of failure, whether with respect to the fuel component or to any other transport, communication, or life-support component of the enterprise? Keep in mind what dicky O-rings, loose bits of insulation foam, dodgy tile adhesive, and metric/imperial confusion has done to NASA’s efforts over the decades: and all this with levels of complexity much less than is required for interplanetary migration.

    “Pretty much the same”? I don’t think so; I think our galaxy is good for quite a few more stellar generations and associated red dwarves yet; I’d back the latter to be around at least several orders of magnitude longer than Sol. Worth a shot, I reckon.

    In terms of the life span of our planet, the life of the universe is pretty much the same order of magnitude with respect to relevance to the survival of our species. Pinning upon the fantasy of interplanetary travel all of humanity’s chances for a decent run on evolution’s treadmill is a pie-in-the-sky, extreme-risk strategy indeed.

    The only other person I’ve heard come out with similar-sounding overwrought pessimism is the ridiculous Jeff Goldblum character in Jurassic Park and its sequel.

    The it would appear Mark that you don’t read very widely at all beyond a certain subgenre of science fiction.

    And I propose that ‘fundamental’ is actually not a very big statement. All growth processes relevant to life processes have asymptotes, except in the minds of many economists and futurists. There are folk from both of these disciplines who are well (and deservedly) recognised as being leaders in their fields, but who displpay asymptotically-constrained-growth and vulnerability-to-complexity scotomata in spite of the best evidence before them. Dyson’s trees and spheres spring to mind…

    And after all of this, the fact still remains that for the asymptotically-100% majority of life on this planet, Earth is the only spaceship/location that will ever be home. If we assume that we can hoist it all somewhere else, lock, stock and barrel, when we’ve shitted too much in this planetary nest, then humanity’s extinction at least is guaranteed.


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