Saturday, May 23, 2009

Peak food

Our food supply floats on an ocean of petroleum, whose peak is now.

Peak oil has become part of the common parlance: the time when global production of oil reaches an all-time peak, followed by inexorable decline. Whether that peak is now or a few years away, rising demand will outstrip supply and dramatically increase prices as soon as the economic system gets back to normal. An analysis of the oil price spikes of 2008 indicates that while some of the rise was due to speculation in a classic bubble, most was due to real supply-demand dynamics, (reflecting low demand elasticity), which will re-assert themselves soon enough.

The price spikes in oil encouraged the diversion of food (corn) to fuel (ethanol) in the US. This contributed to a spike in food prices around the world which caused quite a few political problems. Another connection between fuel and food is that modern agriculture is heavily fuel-intensive, using (in the case of corn) about 140 gallons of (fossil) fuel per acre. To put this in perspective, that is enough to drive a 25 mpg car from coast to coast in the US. One estimate puts fuels used in agriculture at three calories for every food calorie consumed, amounting in the US to ten percent of fuel use. Rising fuel scarcity and cost will increase costs of fertilizer, machinery, processing, and ultimately, food. Poor countries will be most susceptible, especially when the green revolution, which is strongly fossil fuel-based, meets high fuel prices in competition with wealthier users.

Food systems also face other limitations such as amounts of arable land and water. A great deal of irrigation water is pumped from aquifers that are rapidly depleting, and in some cases from fossil aquifers that will never be replenished. Climate change derived from the fossil fuels already consumed is altering the availability of arable land, reducing areas in the tropics where higher heat can cause outright desertification or make some crops impossible to grow, and re-scheduling major agricultural rivers that are fed by glaciers. At the same time, climate change may expand arable areas in northerly locations like Siberia. Erosion and desertification are reducing arable land all over the world, since the current monoculture practices, however conservatively practiced, draw down soil resources instead of building them up.

Another critical element is population. All of nature follows the biological imperative of over-reproduction, spending all immediately available resources on the next generation, which is in turn left to gather what resources it can from the environment. In our case, we have found ways to borrow spectacular amounts of resources from our surroundings that will never be there to support future generations. This certainly applies to fossil fuels, but also to other minerals and to ecological services from the oceans, air, forests, and soils that are being depleted with little thought for the long term. Over the last few centuries we have gotten used to exponential growth in population, which even with the rosiest possible assumptions is unsustainable.

One could conclude that our "developed" way of life is an elaborate ponzi scheme- a lonely peak in earth's human population history, never to be repeated and foretelling harsh conditions on the declining side. Will such harsh conditions be required to restrict human population? Sadly, one has to say that the answer seems to be yes. There is little evidence that human societies are sufficiently conscious of truly long-term sustainability issues to be able to tear themselves away from our well-programmed biological imperatives. Certainly the Pope has no compunction urging continued fertility even in the poorest and most ecologically devastated precincts of his flock. It is only the modern development (and female empowerment) process that values quality over quantity in human reproduction, but at the same time it is the very process that eats us out of house and home in other ways.

Can technology make up the shortfall in resources, especially in energy, as well as mitigate the fallout of ecological devastation? That is not yet clear. Economists tend to be perennial optimists, assuming that, given the right incentives, our rich technological culture will create replacement commodities, in this case literally out of thin air. But just how extreme will those incentives have to get? Will they degrade our ability to live in developed ways? Will they prompt wars for food, water, and fuel? If the green revolution that has been so dependent on leveraging fossil fuels stalls, will poor countries face demographic catastrophe?

Right now the most daunting challenge will be resisting the temptation to double-down on this grand ponzi scheme, mortgaging yet more future resources and biosphere health by fleeing to even dirtier and climate-killing fossil fuels such as tar-sands, oil shales, and coal. That is the ultimate collective question- whether we can rise above what looks in bare economic terms to be an almost inexorable tragedy of the commons by collectively safeguarding earth's environment for those (perhaps fewer) humans and other inhabitants who succeed us.

Incidental links:
  • Black sun takes a rosier view of the technological possibilities
  • While others are more alarmist
  • Liberals have their own angle on the taking-to-the-hills movement
  • Easter Island offers a classic cautionary tale
  • More data on peak oil
  • And in completely other news, corruption continues apace


  1. What if birth control (and cultural tolerance of birth control) had been invented before the Haber process? The human population curve might look much different.

    Human population will have to go down, but there's a good chance it will be voluntary (and not because of starvation).

    Enjoying your blog!

  2. Hi, Mr. Moyer-

    I doubt that birth control is the whole story. Humans have tended always to grow to the extent economically/technologically/ecologically possible throughout history, as Malthus observed. The observation that education of women consistently lowers birth rates is the only thing I have seen that alters this conclusion for the future, as we hope for some kind of plateau in world population. But perhaps as in this post, other ecological constraints will get us first.

    It is ironic for us in the US to talk about this- we have access to birth control, education, and all the cultural resources, yet still consume multiple earths-worth of resources, projected out to the whole human population and to future time. So we should tend to our own wasteful affairs first.

    With appreciation-

  3. Absolutely -- if you read my post you'll see that I agree. I see at 100+ year dark age as the most likely scenario, reversing only when energy production once again overtakes energy demand (due to lower population and/or better energy production technologies).

    Birth control only matters if it is accompanied by increases in womens' education and access to healthcare. Some countries (for example Mexico and Bangladesh) have made huge strides with rural outreach programs emphasizing birth spacing. China's one-child policy, on the other hand, has resulted in massive female infanticide.

    Of course we should attend to our own affairs, as you say, but shouldn't we also fully support effective international programs that help provide clean water, health clinics, schools, for girls, etc? I like the work charity:water is doing. Do you have any favorites?