The Oil Intensity of Food
Lester R. BrownToday we are an oil-based civilization, one that is totally dependent on a resource whose production will soon be falling. Since 1981, the quantity of oil extracted has exceeded new discoveries by an ever-widening margin. In 2008, the world pumped 31 billion barrels of oil but discovered fewer than 9 billion barrels of new oil. World reserves of conventional oil are in a free fall, dropping every year.
Discoveries of conventional oil total roughly 2 trillion barrels, of which 1 trillion have been extracted so far, with another trillion barrels to go. By themselves, however, these numbers miss a central point. As security analyst Michael Klare notes, the first trillion barrels was easy oil, “oil that’s found on shore or near to shore; oil close to the surface and concentrated in large reservoirs; oil produced in friendly, safe, and welcoming places.” The other half, Klare notes, is tough oil, “oil that’s buried far offshore or deep underground; oil scattered in small, hard-to-find reservoirs; oil that must be obtained from unfriendly, politically dangerous, or hazardous places.”
This prospect of peaking oil production has direct consequences for world food security, as modern agriculture depends heavily on the use of fossil fuels. Most tractors use gasoline or diesel fuel. Irrigation pumps use diesel fuel, natural gas, or coal-fired electricity. Fertilizer production is also energy-intensive. Natural gas is used to synthesize the basic ammonia building block in nitrogen fertilizers. The mining, manufacture, and international transport of phosphates and potash all depend on oil.
Efficiency gains can help reduce agriculture’s dependence on oil. In the United States, the combined direct use of gasoline and diesel fuel in farming fell from its historical high of 7.7 billion gallons (29.1 billion liters) in 1973 to 4.2 billion in 2005—a decline of 45 percent. Broadly calculated, the gallons of fuel used per ton of grain produced dropped from 33 in 1973 to 12 in 2005, an impressive decrease of 64 percent.
One reason for this achievement was a shift to minimum- and no-till cultural practices on roughly two fifths of U.S. cropland. But while U.S. agricultural fuel use has been declining, in many developing countries it is rising as the shift from draft animals to tractors continues. A generation ago, for example, cropland in China was tilled largely by draft animals. Today much of the plowing is done with tractors.
Fertilizer accounts for 20 percent of U.S. farm energy use. Worldwide, the figure may be slightly higher. As the world urbanizes, the demand for fertilizer climbs. As people migrate from rural areas to cities, it becomes more difficult to recycle the nutrients in human waste back into the soil, requiring the use of more fertilizer. Beyond this, the growing international food trade can separate producer and consumer by thousands of miles, further disrupting the nutrient cycle. The United States, for example, exports some 80 million tons of grain per year—grain that contains large quantities of basic plant nutrients: nitrogen, phosphorus, and potassium. The ongoing export of these nutrients would slowly drain the inherent fertility from U.S. cropland if the nutrients were not replaced.
Irrigation, another major energy claimant, is requiring more energy worldwide as water tables fall. In the United States, close to 19 percent of farm energy use is for pumping water. And in some states in India where water tables are falling, over half of all electricity is used to pump water from wells. Some trends, such as the shift to no-tillage, are making agriculture less oil-intensive, but rising fertilizer use, the spread of farm mechanization, and falling water tables are having the opposite effect.
Although attention commonly focuses on energy use on the farm, agriculture accounts for only one fifth of the energy used in the U.S. food system. Transport, processing, packaging, marketing, and kitchen preparation of food are responsible for the rest. The U.S. food economy uses as much energy as the entire economy of the United Kingdom.
The 14 percent of energy used in the food system to move goods from farmer to consumer is equal to two thirds of the energy used to produce the food. And an estimated 16 percent of food system energy use is devoted to canning, freezing, and drying food—everything from frozen orange juice concentrate to canned peas.
Food staples such as wheat have traditionally moved over long distances by ship, traveling from the United States to Europe, for example. What is new is the shipment of fresh fruits and vegetables over vast distances by air. Few economic activities are more energy-intensive.
Food miles—the distance that food travels from producer to consumer—have risen with cheap oil. At my local supermarket in downtown Washington, D.C., the fresh grapes in winter typically come by plane from Chile, traveling almost 5,000 miles. One of the most routine long-distance movements of fresh produce is from California to the heavily populated U.S. East Coast. Most of this produce moves by refrigerated trucks. In assessing the future of long-distance produce transport, one writer observed that the days of the 3,000-mile Caesar salad may be numbered.
Packaging is also surprisingly energy-intensive, accounting for 7 percent of food system energy use. It is not uncommon for the energy invested in packaging to exceed that in the food it contains. Packaging and marketing also can account for much of the cost of processed foods. The U.S. farmer gets about 20 percent of the consumer food dollar, and for some products, the figure is much lower. As one analyst has observed, “An empty cereal box delivered to the grocery store would cost about the same as a full one.”
The most energy-intensive segment of the food chain is the kitchen. Much more energy is used to refrigerate and prepare food in the home than is used to produce it in the first place. The big energy user in the food system is the kitchen refrigerator, not the farm tractor. While oil dominates the production end of the food system, electricity dominates the consumption end.
In short, with higher energy prices and a limited supply of fossil fuels, the modern food system that evolved when oil was cheap will not survive as it is now structured.
Earth Policy Institute
Oxfam Calls for New Approach to Hunger
Integrated Regional Information Networks (IRIN)NAIROBI, Oct 22 (IRIN) - With droughts becoming more common, donors and the Ethiopian government must look beyond the traditional "band aid" responses to disasters by using approaches that are more cost-effective, sustainable and better suited to the population, international aid agency Oxfam says in a new report.
"We cannot make the rains come, but there is much more that we can do to break the cycle of drought-driven disaster in Ethiopia and the Horn of Africa," Penny Lawrence, Oxfam's international director, states. "Food aid offers temporary relief and has kept people alive in countless situations, but does not tackle the underlying causes that continue to make people vulnerable to disaster year after year."
Oxfam issued the report, Band Aids and Beyond, on 22 October, the 25th anniversary of one of Ethiopia's worst famines when an estimated one million people died. The report looks at how aid has worked since 1984, arguing that the current donor trend of focusing on emergency food aid had to change.
"Donors need to shift their approach, and help to give communities the tools to tackle disasters before they strike," Lawrence said. "Drought does not need to mean hunger and destitution. If communities have irrigation for crops, grain stores and wells to harvest rains then they can survive despite what the elements throw at them."
Calling for a radical shake-up in the way the world tackled food crises, Oxfam said it was essential that donors rise to the challenge and provide adequate funding for emergency assistance for this year's crisis, adding: "Current responses by international donors are far below requirements estimated by governments and UN agencies."
New approach
In the report, Oxfam argues that "it is equally essential that donors do more to back programmes that manage the risk of the disaster before it strikes, such as early warning systems, creating strategically positioned stockpiles of food, medicine and other items, and irrigation programmes.
"For instance, in Somali region, Oxfam is building birkhads, or protected wells, to enable communities to 'harvest' rain during the rainy season to make sure there is more water available nearby when the rains stop. These types of programmes receive just 0.14 percent of overseas aid."
Climate change threat
"Climate scientists predict that by 2034, the 50th anniversary of the 1984 Ethiopia famine, what are now droughts will become the norm, hitting the region three years out of every four," Oxfam said. "A shift of approach is needed to prevent climate shocks developing into disasters which will push more people into poverty."
Lawrence said: "Climate change makes the urgency of this approach greater than ever before. Ethiopians on the frontline of climate change cannot wait another 25 years for common sense to become common practice."
World hungerOn 16 October, another international aid agency, ActionAid, issued a report, Who's really fighting hunger, questioning why one billion people the world over were hungry.
"Over one billion people -- a sixth of humanity -- don't have enough to eat," ActionAid said. "Almost a third of the world's children are growing up malnourished. This is perhaps one of the most shameful achievements of recent history, since there is no good reason for anyone to go hungry in today's world."
However, ActionAid said hunger was a choice man makes, "not a force of nature."
It added: "Hunger begins with inequality -- between men and women, and between rich and poor. It grows because of perverse policies that treat food purely as a commodity, not a right. It is because of these policies that most developing countries no longer grow enough to feed themselves, and that their farmers are among the hungriest and poorest people in the world. Meanwhile, the rich world battles growing obesity."
Arguing that policies can be changed, ActionAid detailed the dramatic progress made when countries translated the right to food into concrete actions, "such as investing in poor farmers, and introducing basic measures to protect the vulnerable. Their success makes the inaction and apathy of other countries all the more inexcusable."
Artificial Photosynthesis: Turning Sunlight
Into Liquid Fuels Moves A Step CloserScienceDaily (Mar. 12, 2009) — For millions of years, green plants have employed photosynthesis to capture energy from sunlight and convert it into electrochemical energy. A goal of scientists has been to develop an artificial version of photosynthesis that can be used to produce liquid fuels from carbon dioxide and water.
Researchers with the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) have now taken a critical step towards this goal with the discovery that nano-sized crystals of cobalt oxide can effectively carry out the critical photosynthetic reaction of splitting water molecules.
“Photooxidation of water molecules into oxygen, electrons and protons (hydrogen ions) is one of the two essential half reactions of an artifical photosynthesis system - it provides the electrons needed to reduce carbon dioxide to a fuel,” said Heinz Frei, a chemist with Berkeley Lab’s Physical Biosciences Division, who conducted this research with his postdoctoral fellow Feng Jiao. “Effective photooxidation requires a catalyst that is both efficient in its use of solar photons and fast enough to keep up with solar flux in order to avoid wasting those photons. Clusters of cobalt oxide nanocrystals are sufficiently efficient and fast, and are also robust (last a long time) and abundant. They perfectly fit the bill.”
Frei and Jiao have reported the results of their study in the journal Angewandte Chemie. This research was performed through the Helios Solar Energy Research Center (Helios SERC), a scientific program at Berkeley Lab under the direction of Paul Alivisatos, which is aimed at developing fuels from sunlight. Frei serves as deputy director of Helios SERC.
Artificial photosynthesis for the production of liquid fuels offers the promise of a renewable and carbon-neutral source of transportation energy, meaning it would not contribute to the global warming that results from the burning of oil and coal. The idea is to improve upon the process that has long-served green plants and certain bacteria by integrating into a single platform light-harvesting systems that can capture solar photons and catalytic systems that can oxidize water - in other words, an artificial leaf.
“To take advantage of the flexibility and precision by which light absorption, charge transport and catalytic properties can be controlled by discrete inorganic molecular structures, we have been working with polynuclear metal oxide nanoclusters in silica,” Frei said. “In earlier work, we found that iridium oxide was efficient and fast enough to do the job, but iridium is the least abundant metal on earth and not suitable for use on a very large scale. We needed a metal that was equally effective but far more abundant.”
Green plants perform the photooxidation of water molecules within a complex of proteins called Photosystem II, in which manganese-containing enzymes serve as the catalyst. Manganese-based organometallic complexes modeled off Photosystem II have shown some promise as photocatalysts for water oxidation but some suffer from being water insoluble and none are very robust.
In looking for purely inorganic catalysts that would dissolve in water and would be far more robust than biomimetic materials, Frei and Jiao turned to cobalt oxide, a highly abundant material that is an an important industrial catalyst. When Frei and Jiao tested micron-sized particles of cobalt oxide, they found the particles were inefficient and not nearly fast enough to serve as photocatalysts. However, when they nano-sized the particles it was another story.
“The yield for clusters of cobalt oxide (Co3O4) nano-sized crystals was about 1,600 times higher than for micron-sized particles,” said Frei, “and the turnover frequency (speed) was about 1,140 oxygen molecules per second per cluster, which is commensurate with solar flux at ground level (approximately 1,000 Watts per square meter).”
Frei and Jiao used mesoporous silica as their scaffold, growing their cobalt nanocrystals within the naturally parallel nanoscale channels of the silica via a technique known as “wet impregnation.” The best performers were rod-shaped crystals measuring 8 nanometers in diameter and 50 nanometers in length, which were interconnected by short bridges to form bundled clusters. The bundles were shaped like a sphere with a diameter of 35 nanometers. While the catalytic efficiency of the cobalt metal itself was important, Frei said the major factor behind the enhanced efficiency and speed of the bundles was their size.
“We suspect that the comparatively very large internal area of these 35 nanometer bundles (where catalysis takes place) was the main factor behind their increased efficiency,” he said, “because when we produced larger bundles (65 nanometer diameters), the internal area was reduced and the bundles lost much of that efficiency gain.”
Frei and Jiao will be conducting further studies to gain a better understanding of why their cobalt oxide nanocrystal clusters are such efficient and high-speed photocatalysts and also looking into other metal oxide catalysts. The next big step, however, will be to integrate the water oxidation half reaction with the carbon dioxide reduction step in an artificial leaf type system.
“The efficiency, speed and size of our cobalt oxide nanocrystal clusters are comparable to Photosystem II,” said Frei. “When you factor in the abundance of cobalt oxide, the stability of the nanoclusters under use, the modest overpotential and mild pH and temperature conditions, we believe we have a promising catalytic component for developing a viable integrated solar fuel conversion system. This is the next important challenge in the field of artificial photosynthesis for fuel production.”
The Helios Solar Energy Research Center is supported by the Director, Office of Science, Office of Basic Energy Sciences of the U.S. Department of Energy.