Threats
of Peak Oil to the Global Food Supply
by Richard Heinberg on 23 June 2006 on
www.museletter.com
A paper presented at the FEASTA Conference, "What Will We
Eat as the Oil Runs Out?", June 23-25, 2005, Dublin IrelandFood
is energy. And it takes energy to get food. These two facts, taken
together, have always established the biological limits to the
human population and always will.
The same is true for every other species: food must yield more
energy to the eater than is needed in order to acquire the food.
Woe to the fox who expends more energy chasing rabbits than he
can get from eating the rabbits he catches. If this energy balance
remains negative for too long, death results; for an entire species,
the outcome is a die-off event, perhaps leading even to extinction.
Humans have become champions at developing new strategies for
increasing the amount of energy - and food - they capture from
the environment. The harnessing of fire, the domestication of
plants and animals, the adoption of ards and plows, the deployment
of irrigation networks, and the harnessing of traction animals
- developments that occurred over tens of thousands of years -
all served this end.
The process was gradual and time-consuming. Not only were new
tools developed, but, over centuries, small inventions and tiny
modifications of existing tools - from scythes to horse-collars
- enabled human and animal muscle power to be leveraged more effectively.
This entire exercise took place within a framework of natural
limits. The yearly input of solar radiation to the planet was
always immense relative to human needs (and still is), but it
was finite nevertheless, and while humans directly appropriated
only a tiny proportion of this abundance the vast majority of
that radiation served functions that indirectly supported human
existence - giving rise to air currents by warming the surface
of the planet, and maintaining the lives of countless other kinds
of creatures in the oceans and on land.
The amount of available human muscle power was limited by the
number of humans, who, of course, had to be fed. Draft animals
(bred for their muscle-power) also entailed energy costs, as they
likewise needed to eat but also had to be cared for in various
ways. Therefore, even with clever refinements in tools and techniques,
in crops development and animal breeding, it was inevitable that
humans would reach a point of diminishing returns in their ability
to continue increasing their energy harvest, and therefore the
size of their population.
By the nineteenth century these limits were beginning to become
apparent.
Famine and hunger had long been common throughout even the wealthiest
regions of the planet. But, for Europeans, the migration of surplus
populations to other nations, crop rotation, and the application
of manures and composts were gradually making those events less
frequent and severe. European farmers, realizing the need for
a new nitrogen source in order to continue feeding burgeoning
and increasingly urbanized populations, began employing guano
imported from islands off the coasts of Chile and Peru. The results
were gratifying. However, after only a few decades, these guano
deposits were being depleted. By this time, in the late 1890s,
the world's population was nearly twice what it had been at the
beginning of the century. A crisis was again in view.
But again crisis was narrowly averted, this time due to fossil
fuels. In 1909, two German chemists named Fritz Haber and Carl
Bosch invented a process to synthesize ammonia from atmospheric
nitrogen and the hydrogen in fossil fuels. The process initially
used coal as a feedstock, though later it was adapted to use natural
gas. After the end of the Great War, nation after nation began
building Haber-Bosch plants; today the process produces 150 million
tons of ammonia-based fertilizer per year, equaling the total
amount of available nitrogen introduced annually by all natural
sources combined.
Fossil fuels went on to offer still other ways of extending natural
limits to the human carrying capacity of the planet.
Early steam-driven tractors came into limited use in 19th century;
but, after World War I, the size and effectiveness of powered
farm machinery expanded dramatically, and the scale of use exploded,
especially in North America, Europe, and Australia from the 1920s
through the '50s. In the 1890s, roughly one quarter of US cropland
had to be set aside for the growing of grain to feed horses -
most of which worked on farms. The internal combustion engine
provided a new kind of horsepower not dependent on horses at all,
and thereby increased the amount of arable land available to feed
humans.
Chemists developed synthetic pesticides and herbicides in increasing
varieties after WWII, using knowledge pioneered in laboratories
that had worked to perfect explosives and other chemical warfare
agents. Pesticides not only increased crop yields in North America,
Europe, and Australia, but also reduced the prevalence of insect-borne
diseases like malaria. The world began to enjoy the benefits of
"better living through chemistry," though the environmental
costs, in terms of water and soil pollution and damage to vulnerable
species, would only later become widely apparent.
In the 1960s, industrial-chemical agricultural practices began
to be exported to what by that time was being called the Third
World: this was glowingly dubbed the Green Revolution, and it
enabled a tripling of food production during the ensuing half-century.
At the same time, the scale and speed of distribution of food
increased. This also constituted a means of increasing carrying
capacity, though in a more subtle way.
The trading of food goes back to Paleolithic times; but, with
advances in transport, the quantities and distances involved gradually
increased. Here again, fossil fuels were responsible for a dramatic
discontinuity in the previously slow pace of growth. First by
rail and steamship, then by truck and airplane, immense amounts
of grain and ever-larger quantities of meat, vegetables, and specialty
foods began to flow from countryside to city, from region to region,
and from continent to continent.
William Catton, in his classic book Overshoot, terms the trade
of essential life-support commodities "scope expansion."1
Carrying capacity is always limited by whatever necessity is in
least supply, as Justus von Liebig realized nearly a century-and-a-half
ago. If one region can grow food but has no exploitable metal
deposits, its carrying capacity is limited by the lack of metals
for the production of farm tools. Another region may have metals
but insufficient topsoil or rain; there, carrying capacity is
limited by the lack of food. If a way can be found to make up
for local scarcity by taking advantage of distant abundance (as
by exporting metal ores or finished tools from region A to help
with food production in region B, and then exporting food from
B to A), the total carrying capacity of the two regions combined
can be increased substantially. We can put this into a crude formula:
CC of A+B > (CC of A) + (CC of B)
From an ecological as well as an economic point of view, this
is why people trade. But trade has historically been limited by
the amount of energy that could be applied to the transport of
materials. Fossil fuels temporarily but enormously expanded that
limit.
The end result of chemical fertilizers, plus powered farm machinery,
plus increased scope of transportation and trade, was not just
a three-fold leap in crop yields, but a similar explosion of human
population, which has grown five-fold since dawn of industrial
revolution.
Agriculture
at a Crossroads
All of this would be well and good if it were sustainable, but,
if it proves not to be, then a temporary exuberance of the human
species will have been purchased by an eventual, unprecedented
human die-off. So how long can the present regime be sustained?
Let us briefly survey some of the current trends in global food
production and how they are related to the increased use of inexpensive
fossil fuels.
Arable cropland: For millennia, the total amount of arable cropland
gradually increased due to the clearing of forests and brush,
and the irrigation of land that would otherwise be too arid for
cultivation. That amount reached a maximum within the past two
decades and is now decreasing because of the salinization of irrigated
soils and the relentless growth of cities, with their buildings,
roads, and parking lots. Irrigation has become more widespread
because of the availability of cheap energy to operate pumps,
while urbanization is largely a result of cheap fuel-fed transportation
and the flushing of the peasantry from the countryside as a consequence
of their inability to buy or to compete with fuel-fed agricultural
machinery. Roads that cover former cropland are built from oil,
and the erection of buildings has been facilitated by the mechanization
of construction processes and the easy transport of materials.
Topsoil: The world's existing soils were generated over thousands
and millions of years at a rate averaging an inch per 500 years.
The amount of soil available to farmers is now decreasing at an
alarming rate, due mostly to wind and water erosion. In the US
Great Plains, roughly half the quantity in place at the beginning
of the last century is now gone. In Australia, after two centuries
of European land-use, more than 70 percent of land has become
seriously degraded.2 Erosion is largely a function of tillage,
which fractures and loosens soil; thus, as the introduction of
fuel-fed tractors has increased the ease of tillage, the rate
of soil loss has increased dramatically.
The number of farmers as a percentage of the population: In the
US at the turn of the last century, 70 percent of the population
lived in rural areas and farmed. Today less than two percent of
Americans farm for a living. This change came primarily because
fuel-fed farm machinery replaced labor, which meant that fewer
farmers were needed. Hundreds of thousands - perhaps millions
- of families that desperately wanted to farm could not continue
to do so because they could not afford the new machines, or could
not compete with their neighbors who had them. Another way of
saying this is that economies of scale (driven by mechanization)
gave an advantage to ever-larger farms. But the loss of farmers
also meant a gradual loss of knowledge of how to farm and a loss
of rural farming culture. Many farmers today merely follow the
directions on bags of fertilizer or pesticide, and live so far
from their neighbors that their children have no desire to continue
the agricultural way of life.
The genetic diversity of domesticated crop varieties: This is
decreasing dramatically due to the consolidation of the seed industry.
Farmers on the island of Bali in Indonesia once planted 200 varieties
of rice, each adapted to a different microclimate; now only four
varieties are grown. In 2000, Semenis, the world's largest vegetable
seed corporation, eliminated 25 percent of its product line as
a cost-cutting measure. This ongoing, massive genetic consolidation
is also being driven by the centralization of the seed industry
(the largest three field seed companies - DuPont, Monsanto, and
Novartis - now account for 20 percent of the global seed trade),
which is in turn consequent upon fuel-fed globalization.
Grain production per capita: A total of 2,029 million tons of
grain were produced globally in 2004; this was a record in absolute
numbers. But for the past two decades population has grown faster
than grain production, so there is actually less available on
a per-head basis. In addition, grain stocks are being drawn down:
According to Lester Brown of the Earth Policy Institute, "in
each of the last four . . . years production fell short of consumption.
The shortfalls of nearly 100 million tons in 2002 and again in
2003 were the largest on record."3 This trend suggests that
the strategy of boosting food production by the use of fossil
fuels is already yielding diminishing returns.
Global climate: This is being increasingly destabilized as a result
of the famous greenhouse effect, resulting in problems for farmers
that are relatively minor now but that are likely to grow to catastrophic
proportions within the next decade or two. Global warming is now
almost universally acknowledged as resulting from CO2 emissions
from the burning of fossil fuels.
Available fresh water: In the US, 85 percent of fresh water use
goes toward agricultural production, requiring the drawing down
of ancient aquifers at far above their recharge rates. Globally,
as water tables fall, ever more powerful pumps must be used to
lift irrigation water, requiring ever more energy usage. By 2020,
according to the Worldwatch Institute and the UN, virtually every
country will face shortages of fresh water.
The effectiveness of pesticides and herbicides: In the US, over
the past two decades pesticide use has increased 33-fold, yet,
each year a greater amount of crops is lost to pests, which are
evolving immunities faster than chemists can invent new poisons.
Like falling grain production per capita, this trend suggests
a declining return from injecting the process of agricultural
production with still more fossil fuels.
Now, let us add to this picture the imminent peak in world oil
production. This will make machinery more expensive to operate,
fertilizers more expensive to produce, and transportation more
expensive. While the adoption of fossil fuels created a range
of problems for global food production, as we have just seen,
the decline in the availability of cheap oil will not immediately
solve those problems; in fact, over the short term they will exacerbate
them, bringing simmering crises to a boil.
That is because the scale of our dependency on fossil fuels has
grown to enormous proportions.
In the US, agriculture is directly responsible for well over 10
percent of all national energy consumption. Over 400 gallons of
oil equivalent are expended to feed each American each year. About
a third of that amount goes toward fertilizer production, 20 percent
to operate machinery, 16 percent for transportation, 13 percent
for irrigation, 8 percent for livestock raising, (not including
the feed), and 5 percent for pesticide production. This does not
include energy costs for packaging, refrigeration, transportation
to retailers, or cooking.
Trucks move most of the world's food, even though trucking is
ten times more energy-intensive than moving food by train or barge.
Refrigerated jets move a small but growing proportion of food,
almost entirely to wealthy industrial nations, at 60 times the
energy cost of sea transport.
Processed foods make up three-quarters of global food sales by
price (though not by quantity). This adds dramatically to energy
costs: for example, a one-pound box of breakfast cereal may require
over 7,000 kilocalories of energy for processing, while the cereal
itself provides only 1,100 kilocalories of food energy.
Over all - including energy costs for farm machinery, transportation,
and processing, and oil and natural gas used as feedstocks for
agricultural chemicals - the modern food system consumes roughly
ten calories of fossil fuel energy for every calorie of food energy
produced.
But the single most telling gauge of our dependency is the size
of the global population. Without fossil fuels, the stupendous
growth in human numbers that has occurred over the past century
would have been impossible. Can we continue to support so many
people as the availability of cheap oil declines?
Feeding
a Growing Multitude
The problems associated with the modern global food system are
widely apparent, there is widespread concern over the sustainability
of the enterprise, and there is growing debate over the question
of how to avoid an agricultural Armageddon. Within this debate
two viewpoints have clearly emerged.
The first advises further intensification of industrial food production,
primarily via the genetic engineering of new crop and animal varieties.
The second advocates ecological agriculture in its various forms
- including organic, biodynamic, Permaculture, and Biointensive
methods.
Critics of the latter contend that traditional, chemical-free
forms of agriculture are incapable of feeding the burgeoning human
population. Here is a passage by John John Emsley of University
of Cambridge, from his review of Vaclav Smil's Enriching the Earth:
Fritz Haber, Carl Bosch, and the Transformation of World Food:
If crops are rotated and the soil is fertilized with compost,
animal manure and sewage, thereby returning as much fixed nitrogen
as possible to the soil, it is just possible for a hectare of
land to feed 10 people - provided they accept a mainly vegetarian
diet. Although such farming is almost sustainable, it falls short
of the productivity of land that is fertilized with "artificial"
nitrogen; this can easily support 40 people, and on a varied diet.
This seems unarguable on its face. However, given the fact that
fossil fuels are non-renewable, it will be increasingly difficult
to continue to supply chemical fertilizers in present quantities.
Nitrogen can be synthesized using hydrogen produced from the electrolysis
of water, with solar or wind power as a source of electricity.
But currently no ammonia is being commercially produced this way
because of the uncompetitive cost of doing so. To introduce and
scale up the process will require many years and considerable
investment capital.
The bioengineering of crop and animal varieties does little or
nothing to solve this problem. One can fantasize about modifying
maize or rice to fix nitrogen in the way that legumes do, but
so far efforts in that direction have failed. Meanwhile, the genetic
engineering of complex life forms on a commercial scale appears
to pose unprecedented environmental hazards, as has been amply
documented by Dr. Mae Wan-Ho among many others.6 And the bio-engineering
industry itself consumes fossil fuels, and assumes the continued
availability of oil for tractors, transportation, chemicals production,
and so on.
Those arguing in favor of small-scale, ecological agriculture
tend to be optimistic about its ability to support large populations.
For example, the 2002 Greenpeace report, "The Real Green
Revolution: Organic and Agroecological Farming in the South,"
while acknowledging the lack of comparative research on the subject,
nevertheless notes:
In general . . . it is thought that [organic and agroecological
farming] can bring significant increases in yields in comparison
to conventional farming practices. Compared to "Green Revolution'"farming
systems, OAA is thought to be neutral in terms of yields, although
it brings other benefits, such as reducing the need for external
inputs.
Eco-agricultural advocates often contend that there is plenty
of food in the world; existing instances of hunger are due to
bad policy and poor distribution. With better policy and distribution,
all could easily be fed. Thus, given the universally admitted
harmful environmental consequences of conventional chemical farming,
the choice should be simple.
Some eco-ag proponents are even more sanguine, and suggest that their methods can produce far higher yields than can mechanized, chemical-based agriculture. Experiments have indeed shown that small-scale, biodiverse gardening or farming can be considerably more productive on a per-hectare basis than monocropped megafarms.8 However, some of these studies have ignored the energy and land-productivity costs of manures and composts imported onto the study plots. In
any case, and there is no controversy on this point, Permaculture and Biointensive forms of horticulture are dramatically more labor- and knowledge-intensive than industrial agriculture. Thus the adoption of these methods will require an economic transformation of societies.
Therefore even if the nitrogen problem can be solved in principle
by agro-ecological methods and/or hydrogen production from renewable
energy sources, there may be a carrying-capacity bottleneck ahead
in any case, simply because of the inability of societies to adapt
to these very different energy and economic needs quickly enough,
and also because of the burgeoning problems mentioned above (loss
of fresh water resources, unstable climate, etc.). According to
widely-accepted calculations, humans are presently appropriating
at least 40 percent of Earth's primary biological productivity.9
It seems unlikely that we, a single species after all, can do
much more than that. Even though it may not be politically correct
in many circles to discuss the population problem, we must recognize
that we are nearing or past fundamental natural limits, no matter
which course we pursue.
Given the fact that fossil fuels are limited in quantity and we
are already in view of the global oil production peak, the debate
over the potential productivity of chemical-gene engineered agriculture
versus that of organic and agroecological farming may be relatively
pointless. We must turn to a food system that is less fuel-reliant,
even if it does prove to be less productive.The Example of Cuba
How we might do that is suggested by perhaps the best recent historical
example of a society experiencing a fossil-fuel famine. In the
late 1980s, farmers in Cuba were highly reliant on cheap fuels
and petrochemicals imported from the Soviet Union, using more
agrochemicals per acre than their American counterparts. In 1990,
as the Soviet empire collapsed, Cuba lost those imports and faced
an agricultural crisis. The population lost 20 pounds on average
and malnutrition was nearly universal, especially among young
children. The Cuban GDP fell by 85 percent and inhabitants of
the island nation experienced a substantial decline in their material
standard of living.
Cuban authorities responded by breaking up large state-owned farms,
offering land to farming families, and encouraging the formation
of small agricultural co-ops. Cuban farmers began employing oxen
as a replacement for the tractors they could no longer afford
to fuel. Cuban scientists began investigating biological methods
of pest control and soil fertility enhancement. The government
sponsored widespread education in organic food production, and
the Cuban people adopted a mostly vegetarian diet out of necessity.
Salaries for agricultural workers were raised, in many cases to
above the levels of urban office workers. Urban gardens were encouraged
in parking lots and on public lands, and thousands of rooftop
gardens appeared. Small food animals such as chickens and rabbits
began to be raised on rooftops as well.
As a result of these efforts, Cuba was able to avoid what might
otherwise have been a severe famine. Today the nation is changing
from an industrial to an agrarian society. While energy use in
Cuba is now one-twentieth of that in the US, the economy is growing
at a slow but steady rate. Food production has returned to 90
percent of its pre-crisis levels.
The
Way Ahead
The transition to a non-fossil-fuel food system will take time.
And it must be emphasized that we are discussing a systemic transformation
- we cannot just remove oil in the forms of agrochemicals from
the current food system and assume that it will go on more or
less as it is. Every aspect of the process by which we feed ourselves
must be redesigned. And, given the likelihood that global oil
peak will occur soon, this transition must occur at a rapid pace,
backed by the full resources of national governments.
Without cheap transportation fuels we will have to reduce the
amount of food transportation that occurs, and make necessary
transportation more efficient. This implies increased local food
self-sufficiency. It also implies problems for large cities that
have been built in arid regions capable of supporting only small
populations on their regional resource base. One has only to contemplate
the local productivity of a place like Nevada, to appreciate the
enormous challenge of continuing to feed people in such a city
such as Las Vegas without easy transportation.
We will need to grow more food in and around cities. Currently,
Oakland California is debating a food policy initiative that would
mandate by 2015 the growing within a fifty-mile radius of city
center of 40 percent of the vegetables consumed in the city.11
If the example of Cuba were followed, rooftop gardens would result,
as well as rooftop raising of food animals like chickens, rabbits
and guinea pigs.
Localization of the food process means moving producers and consumers
of food closer together, but it also means relying on the local
manufacture and regeneration of all of the elements of the production
process - from seeds to tools and machinery. This would appear
to rule out agricultural bioengineering, which favors the centralized
production of patented seed varieties, and discourages the free
saving of seeds from year to year by farmers.
Clearly, we must minimize chemical inputs to agriculture (direct
and indirect - such as those introduced in packaging and processing).
We will need to re-introduce draft animals in agricultural production.
Oxen may be preferable to horses in many instances, because the
former can eat straw and stubble, while the latter would compete
with humans for grains.
Governments must also provide incentives for people to return
to an agricultural life. It would be a mistake simply to think
of this simply in terms of the need for a larger agricultural
work force. Successful traditional agriculture requires social
networks, and intergenerational sharing of skills and knowledge.
We need not just more agricultural workers, but a rural culture
that makes agricultural work rewarding.
Farming requires knowledge and experience, and so we will need
education for a new generation of farmers; but only some of this
education can be generic - much of it must of necessity be locally
appropriate.
It will be necessary as well to break up the corporate mega-farms
that produce so much of today's cheap grain. Industrial agriculture
implies an economy of scale that will be utterly inappropriate
and unworkable for post-industrial food systems. Thus land reform
will be required in order to enable smallholders and farming co-ops
to work their own plots.
In order for all of this to happen, governments must end subsidies
to industrial agriculture and begin subsidizing post-industrial
agricultural efforts. There are many ways in which this could
be done. The present regime of subsidies is so harmful that merely
stopping it in its tracks might in itself be advantageous; but,
given the fact that a rapid transition is essential, offering
subsidies for education, no-interest loans for land purchase,
and technical support during the transition from chemical to organic
production would be essential.
Finally, given carrying-capacity limits, food policy must include
population policy. We must encourage smaller families by means
of economic incentives and improve the economic and educational
status of women in poorer countries.
All of this constitutes a gargantuan task, but the alternatives
- doing nothing or attempting to solve our food-production problems
simply by applying more technological intensification - will almost
certainly result in dire consequences. In that case, existing
farmers would fail because of fuel and chemical prices. All of
the worrisome existing trends mentioned earlier would intensify
to the point that the human carrying capacity of Earth would be
degraded significantly, and perhaps to a large degree permanently.
In sum, the transition to a fossil-fuel-free food system does
not constitute a utopian proposal. It is an immense challenge
and will call for unprecedented levels of creativity at all levels
of society. But in the end it is the only rational option for
averting human calamity on a scale never before seen.
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