Meeting the Challenge of Peak Oil
With Sustainable Agriculture
John Ikerd[1]
Higher prices for gasoline and
other fossil fuels have renewed public interest in alternative sources of
renewable energy, including wind, water, photovoltaic, and bio-fuels. Energy
prices in 2005 were due in part to unpredictable events, such as hurricane
Katrina, but the approaching peak in global oil production makes even higher
energy prices both predictable and inevitable. Peak oil is a concept based on the premise that peaks in oil
production occur when approximately half of the total amount of oil in a particular
oil field has been extracted, which typically occurs some 30-40 years after the
initial discovery. Beyond that point, extraction becomes increasingly difficult
and costly and total production inevitably declines.
Peak oil gained credibility
when U.S. domestic oil production peaked in 1970, thirty-plus years following
the peak in U.S. oil discoveries in the 1930s. The peak in global oil discoveries
occurred later, in the mid-1960s, signaling a peak in global oil production
around the turn of the twenty-first century. Changes in extraction methods and
uncertainty regarding Middle East oil reserve data have made precise
calculations difficult, but most forecasters now place the year of global peak
oil somewhere between 2006 and 2010. Even more optimistic government forecasts
indicate a peak in global production between 2010 and 2015, with a 70% decline
in total oil production by 2050. If major new oil fields were discovered next
year, which is highly unlikely, those fields would not reach peak production
for another 30-40 years. The world quite simply must learn to live with less
oil.
A transition to biological energy
sources is not the solution. The renewable energy produced annually by all
types of plant life within the U.S. amounts to only about two-thirds as much as
total annual U.S. use of non-renewable fossil energy. Agriculture is able to
harvest only a little more than 35% of total plant energy produced – an amount
equivalent to about 25% of total U.S. fossil energy use. Total energy used by
U.S. agriculture amounts to an equivalent of about 6% of total fossil energy
use. This might appear to indicate a significant energy surplus for
agriculture. However, crops that could be consumed directly by humans account
for only about 20% of total agricultural energy production. The remaining 80%
is produced by pastures and forages, which are utilized by livestock in
producing meat, milk, eggs, and other food products. In addition, about 90% of
all food crops produced in the U.S. is fed to livestock and poultry, which on
average require more than 15 kcal of fossil energy for each kcal of food
products. As a result, U.S. agriculture actually uses about three kcal of
fossil energy for each kcal of food energy produced.
In addition, agriculture accounts
for only about one-third of total energy used for U.S. food production,
including food processing and distribution, the total being equivalent to about
17% of total fossil energy used. The U.S. food system in total requires
approximately 10 kcal of fossil energy to produce each kcal of food energy, in
addition to the solar energy harvested by agricultural plants. Agriculture alone
cannot possibly produce enough bio-fuels to offset the future decline in fossil
fuel production. In fact, agriculture faces a formidable challenge in producing
enough renewable energy to meet the growing global food and fiber needs.
Shifting to a vegetarian diet
would be one obvious means of reducing energy use in agriculture, since most
food crops are net energy producers, possibly cutting the food energy
input/output ratio in half. However, energy used and lost in food processing
and distribution would still leave about a five-to-one net fossil energy
deficit for total food production. In addition, the 20% fossil fuel equivalent
produced by pasture and forage plants – large net energy producers – would be
lost. Shifting from confinement livestock feeding operations to grass-based
operations could be a more logical means of reducing the energy used in animal
agriculture. A shift to grass-based systems could save an estimated 35% of
total energy now used in beef, dairy, and lamb production.
Other sustainable farming
practices could reduce agricultural energy use still farther. For example,
research based on more than 20 years of recent data indicates that shifting to
organic farming practices could save as much as 30% of the fossil energy,
without reducing total production. Sustainable grass-based livestock systems,
utilizing management intensive grazing, are capable of producing from 50% to
100% more protein per acre than conventional pasture/forage systems, while
using less fertilizer, pesticides, and fuel. Free-range and pasture-based pork
and poultry also are far more energy efficient than confinement feeding
operations. In addition, hogs and chickens are natural scavengers and thus
could get a significant portion of their diets from waste products. Significant
fossil energy savings from livestock and poultry might well be achievable
without sacrificing healthy levels of animal protein in human diets. Changes in
food processing and distribution in the U.S., such as increased use of raw and
minimally processed foods, more meals prepared at home, and a shift to more
community-based, local food systems, could increase the efficiency of energy
use in food marketing by comparable amounts.
To my knowledge, no detailed
estimates are available, but energy savings from shifting to more-sustainable
agricultural systems, using currently available methods and technologies,
probably could cut total fossil energy use in agriculture by one-half,
resulting in a savings equivalent to about 3% of total fossil energy use.
Similar efficiencies in processing and distribution could save an additional 6%
or so in fossil energy use, but would still leave total food production with an
energy deficit equivalent to 8% of current total fossil energy use in the U.S.
Despite the current enthusiasm for
biological sources of renewable energy, it seems unlikely that agriculture of
the future will be able to produce more energy than will be needed to meet the
increasing food and fiber needs of people. Current agricultural energy
initiatives, specifically those utilizing grain and oilseeds to produce ethanol
and bio-diesel, have shown little promise of ever generating significantly more
energy than they consume. Their primary value seems to be in changing the form
of energy, to provide fuel for motor vehicles, rather than increasing the total
amount of energy available. With a growing world population, reducing the
amount of fossil energy required for food production would seem a far higher public
priority than turning potential food for hungry people into fuel for
automobiles.
Farms may have far more to
contribute in meeting future energy challenge as locations for wind generators
than as producers of energy crops. Current estimates indicate that wind energy
could eventually replace up to 60% of current fossil energy use. However, achieving
this level of production would require large investments in energy transmission
infrastructure in addition to thousands of wind turbines. Wind energy advocates
are currently promoting the development of huge wind farms populated by dozens
to hundreds of multi-million dollar generators. However, such initiatives
reflect the industrial-era thinking that created the energy problem, rather
than a sustainable energy paradigm for the future. A sustainable energy system must
be able to realize the benefits of specialization, standardization, and
consolidation of control, but without sacrificing the diversity, site
specificity, individuality, and decentralization necessary to maintain the
capacity for renewal and regeneration.
On sustainable farms, wind
turbines would be integrated into the overall farming operation, utilizing a
diversity of sizes and strategic locations to accommodate other farming
activities. On large, specialized wind farms, turbines occupy about 2% of land
area. On sustainable farms, the competition for space between generators and
farming would be insignificant. Smaller turbines in less concentrated patterns at
many different locations might be less technically efficient, but would minimize
potential noise pollution and other environmental concerns and would prevent
the tremendous concentration of economic and political power that otherwise
will be associated with energy generation in the future. Supplemental income
from energy generation would also help diversity and sustain large numbers of small
to moderate sized farming operations. Sustainable energy will require
ecological integrity and social responsibility as well as economic efficiency.
A sustainable wind energy system likely
would be a decentralized network, linking hundreds of thousands of farms and
ranches with various numbers and types of wind generators. Windmills would be
scattered across the North American West and Great Plains as well as other specific
areas with wind energy potential. The same transmission lines bringing
electricity to these farms and ranches could be used to carry wind-generated energy
back to the major retransmission points within the network. Such a network
would also allow farmers to help close energy cycles on their farms by
utilizing plant and animal wastes to generate electricity. However, such a
system would require a fundamentally different type of infrastructure and
organizational paradigm from that envisioned for giant, specialized wind farms.
In meeting the challenge of peak
oil, we must not allow agriculture to be viewed with the same industrial
mind-set that has made the global economy so completely dependent on fossil fuel.
Ultimately, we must embrace a material standard of living that will allow unavoidable losses of nonrenewable
energy to be offset by energy captured by living plants, windmills, falling
water, photovoltaic, and other sources of solar energy. To meet the challenge
of peak oil we must respect the rights of those of future generations to meet
their energy needs as we find ways to meet ours, not just find another source
of cheap nonrenewable energy to last through our lifetime. A sustainable
agriculture can help, but meeting the peak oil challenge ultimately will depend
on the willingness of human society to embrace the ecological, social, and economic
principles of sustainability.
Most energy percentages used are based on data from, David and Marcia Pimentel, ed., 1996, Food, Energy, and Society, University Press of Colorado, Niwot, CO.
[1] Sustaining People through Agriculture series,” Small Farm Today Magazine, Missouri Farm Publications, Clark, MO. November-December 2005.