Sustainable Food System for Sustainable Development

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Sustainable Food System for Sustainable Development

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ISIS Press Release 28/07/05

 

Sustainable Food System for Sustainable Development

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Mae-Wan Ho, Director, Sustainable World Global Initiative,

PO Box 32097 London NW1 0XR, UK www.i-sis.org.uk

 

Lecture for Sustainable World International Conference 14-15

July, House of Commons, Westminster, London.

 

The complete version with references and diagrams is posted

on Independent Science Panel website

http://www.indsp.org/pdf/SFSSSD.pdf

 

What's a sustainable food system?

 

That's a question for this conference to answer. But I'll

show you what it is not. Here's a sobering estimate of the

greenhouse gas emissions from eating in a European country,

based on full life cycle accounting, from farm to plate to

waste [1].

 

 

 

Greenhouse gas emissions from eating (France) Agriculture

direct emissions - 42.0 Mt C

Fertilizers (French fertilizer industry only,

more than half imported.) - 0.8

Mt C Road transport goods (within France only,

not counting export/import) - 4.0 Mt C

Road transport people - 1.0 Mt C

Truck manufacture & diesel - 0.8 Mt C

Store heating (20% national total) - 0.4 Mt C

Electricity (nuclear energy in France,

multiply by 5 elsewhere) - 0.7 Mt C

Packaging - 1.5 Mt C

End of life of packaging (overall

emissions of waste 4 Mt) - 1.0 Mt C

 

Total - 5.0 Mt C

National French emission - 171.0 Mt C

Share linked to food system - 30.4%

 

 

The figure of 30.4 percent is clearly an underestimate,

because it leaves out emissions from the fertilizers

imported as well as pesticides, transport associated with

import/export of food, energy spent storing and preparing

food in homes; and emission from electricity is one-fifth of

typical non-nuclear sources.

 

Our current food system is dominated by high agricultural

inputs, including pumped irrigation water, and huge volumes

of commodity export and import, much of it by air. Taking

all those into account could easily increase the greenhouse

gas emissions another 5 to 10 percent of total. That gives a

rough idea of how much scope there is for reducing

greenhouse gas emissions (and energy use) by changing

agricultural practices, cutting out agricultural inputs and

unnecessary transport, storage and packaging through local

production and consumption.

 

Sequestering C in soil provide food security and mitigate

global warming

 

Carbon dioxide in our atmosphere has reached an all-time

high of 379 ppm (parts per million), giving a total of 807

Gt (109 tonnes) of carbon in the earth's atmosphere. This is

still less than a third of the 2 500 Gt of carbon in the

earth's soil, of which 1 550 Gt is organic carbon, and the

rest inorganic carbon. The global soil organic carbon pool

is almost three times the 560 Gt C estimated in all living

organisms [2].

 

The earth has been losing soil organic carbon to the

atmosphere since historic times, a process greatly

accelerated within the past 50 years, as agriculture

intensifies, and forests are cut down to convert to

agricultural land. Estimates for the historic losses of soil

organic carbon range widely from 44 to 537 Gt, with the

common range of 55 to 78 Gt. That is the amount we can

theoretically put back from the atmosphere into the soil as

organic carbon, if we get our agriculture and land use

right.

 

There is significant potential for sequestering, or taking

carbon from the air into the soil through a set of

recommended management practices. On existing croplands

(1.35 billion ha), maximise soil organic carbon and

fertility through organic inputs, cover crops, conservation

tillage and mixed farming; on rangelands and grasslands

(3.7billion ha), prevent overgrazing, fires and loss of

nutrients, on degraded and desertified land (1.1 billion

ha), prevent water and wind erosion, harvest and conserve

water and plant forests; and on irrigated land (0.275

billion ha), control salinity, use drip/sub-irrigation,

provide drainage, enhance water efficiency and conservation.

 

In fact, R. Lal in Ohio State University said [2, p.1626],

" Soil C sequestration is a strategy to achieve food security

through improvement in soil quality " , and as a bonus, it

offsets 0.4 to 1.2Gt C/year, or 5 to 15% of the global

emissions of 7.9Gt C of greenhouse gas due to human

activities each year. Ingrid Hartman will say more soil to-

morrow.

 

Agroforestry for food security and C sequestration

 

Another way to cut emissions is to stop cutting down

forests. Deforestation contributes 1.6 Gt C emissions or 20%

of the annual global greenhouse gas emissions due to human

activities [3]. More than 14 million hectares of forests are

cleared every year, mostly in the tropics [4]. Brazil alone

has lost 47.4 million hectares of its Amazonia forest since

1978 [5], mostly for raising cattle; and in recent years,

for growing soya as cattle feed.

 

Tropical forests are the richest carbon stocks and most

effective carbon sinks in the world. The carbon pool in the

secondary tropical forests in Mt. Makiling Forest Reserve in

the Philippines was assessed at 418tC/ha, of which 40

percent was soil organic carbon [6]; and this forest

sequestered carbon at the rate of 5tC/ha/y. An agro-forestry

system with cacao trees in a forest reserve in southern

Luzon in the Philippines had a mean C pool of 258t/ha [7].

Agroforests in the humid tropics sequester a median of 10t

C/ha/y [8]. Replanting forests for sustainable agro-forestry

creates significant carbon stocks and sinks, and at the same

time, restore livelihood to millions of indigenous peoples

who have been displaced and/or poisoned by cattle ranges,

soya farms, oil and mining industries.

 

Tropical rain forests like those in the Amazon also play a

most crucial role in mitigating global warming by regulating

climate and rainfall [9], which is why they must be

preserved and restored at all costs, as Peter Bunyard will

tell you to-morrow.

 

A profusion of local inventions for sustainable food

production

 

There is a profusion of local inventions for producing food

sustainably, increasing productivity while saving energy and

water, and harvesting energy from farm wastes to reduce

greenhouse gas emissions. They are described in detail in

successive issues of our must-read magazine. I mention a

few.

 

Jesuit priest, Henri de Laulanie, working with farming

communities in Madagascar in the late 1980s invented a

system of rice intensification that is now practiced by 100

000 farmers in the country and spreading to other countries

in Africa and Asia [9,10]. It depends on transplanting rice

seedlings at an earlier age and spaced wider apart than

usual, emphasis on organic inputs, and most importantly,

keeping the soil moist rather than flooded during the

growing season. This encourages the rice plants to put out

more side shoots, grow deeper, stronger roots, increasing

yields from 2t/ha to 8t within the second year, and 12t/ha

or more in later years. These results met with scepticism

from the conventional scientific community; but have been

confirmed by Chinese crop scientist Yuan Longping, co-winner

of 2004 World Food Prize. Other Chinese scientists

documented savings on seeds by 60%, 100% on fertilizers, and

most of all, saving 3 000 tonnes of water/ha.

 

Agricultural wastes are a major source of the most serious

greenhouse gases: methane and nitrous oxide. The perfect

solution is to harvest the methane as `biogas' for energy,

while reducing nitrous oxide emission, saving the nitrogen

as organic fertilizer nutrient for crops. How? By digesting

the agricultural wastes anaerobically (in the absence of

air) with bacteria normally present in the wastes,

especially cattle dung. No one knows who first invented

biogas. Anecdotal evidence suggests that biogas was used for

heating bath water in Assyria during the 10th century BC

[11], and the first digestion plant to produce biogas from

wastes was built in a leper colony in Bombay, India in 1859.

Based on this ancient invention, scientists in the United

States and Canada are recently producing hydrogen, the

ultimate clean fuel, as well as methane from food and

agricultural wastes [12]. Biogas is becoming popular in many

Third World countries, and emerging as a major boon,

bringing health, social, environmental and financial

benefits [13]. Nepal's successful biogas programme saves 625

000 tonnes of carbon dioxide equivalents from being pumped

into the atmosphere each year, earning it US$5 million in

carbon trading that can be invested back into clean energy

to generate yet more income from carbon trading.

 

As you can see, there is a lot of potential for putting in

place post-fossil fuel, minimum-emission food systems,

especially in poor countries; but we are stymied by our

political leaders' overwhelming commitment to a dominant

model of infinite, unbalanced growth that has brought us

global warming and the imminent collapse of food production,

as I mentioned earlier in my introduction to our Global

Initiative.

 

There are many success stories from the grassroots. You will

hear the one about Ethiopia from Sue Edwards to-morrow. I

shall describe another showing how science and indigenous

knowledge can work wonders together [14], which also

illustrates a model of sustainable balanced growth [15-19]

that I believe should replace the dominant model.

 

Environment engineer meets Chinese peasant farmers

 

It sounds like a dream, but it is possible to produce a

super-abundance of food with no fertilizers or pesticides

and with little or no greenhouse gas emission. The key is to

treat farm wastes properly to mine the rich nutrients that

can be returned to the farm, to support the production of

fish, crops, livestock and more; get biogas energy as by-

product, and perhaps most importantly, conserve and release

pure potable water back to the aquifers.

 

Professor George Chan has spent years perfecting the system;

and refers to it as the Integrated Food and Waste Management

System (IFWMS) [20]. I call it " dream farm " for short [14].

 

Chan was born in Mauritius and educated at Imperial College,

London University in the UK, specializing in environmental

engineering. He was director of two important US federal

programmes funded by the Environmental Protection Agency and

the Department of Energy in the US Commonwealth of the

Northern Mariana Islands of the North Pacific. On retiring,

Chan spent 5 years in China among the Chinese peasants, and

confessed he learned just as much there as he did in

University.

 

He and many others were inspired, among them, Gunter Pauli,

the founder and director of the Zero Emissions Research

Initiative (ZERI) (www.zeri.org). Chan has worked with ZERI

since, which has taken him to nearly 80 countries and

territories, and contributed to evolving IFWMS into a

compelling alternative to conventional farming.

 

Treating wastes with respect

 

The secret is in treating wastes to minimize the loss of

valuable nutrients that are used as feed. At the same time,

greenhouse gases emitted from farm wastes are harvested for

use as fuel.

 

Livestock wastes are first digested anaerobically (in the

absence of air) to harvest biogas (mainly methane, CH4). The

partially digested wastes are then treated aerobically (in

the presence of air) in shallow basins with green algae. By

means of photosynthesis, the algae produce all the oxygen

needed to oxidise the wastes to make them safe for fish.

This increases the fertilizer and feed value in the

fishponds without robbing the fish of dissolved oxygen.

Biogas is used, in turn, as a clean energy source for

cooking. This alone, has been a great benefit for women and

children above all [13], saving them from respiratory

diseases caused by inhaling smoke from burning firewood and

cattle dung. It also spares the women the arduous task of

fetching and carrying 60 to 70 lb of firewood each week,

creating free time for studying in the evening or earning

extra income. Biogas energy enables farmers to process their

produce for preservation and added value, reducing spoilage

and increasing the overall benefits.

 

" It can turn all those existing disastrous farming systems,

especially in the poorest countries into economically viable

and ecologically balanced systems that not only alleviate

but eradicate poverty. " Chan says [20].

 

Increasing the recycling of nutrients for greater

productivity

 

The ancient practice of combining livestock and crop had

helped farmers almost all over the world. Livestock manure

is used as fertilizer, and crop residues are fed back to the

livestock.

 

Chan points out, however, that most of the manure, when

exposed to the atmosphere, lost up to half its nitrogen as

ammonia and nitrogen oxides before they can be turned into

stable nitrate that plants use as fertilizer. The more

recent integration of fish with livestock and crop has

helped to reduce this loss [21]. But too much untreated

wastes dumped directly into the fishpond can rob the fish of

oxygen, and end up killing the fish. The most significant

innovation of IFWMS is thus the two-stage method of treating

wastes. The anaerobic digestion not only prevents the loss

of nutrients, but also substantially reduces greenhouse gas

emissions in the form of both methane (harvested as biogas)

and nitrous oxide (saved as nutrient) that go to feed algae

and then fish.

 

To close the circle, which is very important for sustainable

growth, livestock should be fed crops and processing

residues, not wastes from restaurants and slaughterhouses.

Earthworms, silkworms, fungi, insects and other organisms

are also encouraged, as some of them are associated with

producing high value goods such as silk and mushrooms.

 

Proliferating lifecycles for greater productivity

 

The aerobic treatment in the shallow basins depends on

oxygen produced by the green alga Chlorella. Chlorella is

very prolific and can be harvested as a high-protein feed

for chickens, ducks and geese.

 

When the effluent from the Chlorella basins reaches the

fishpond, little or no organic matter from the livestock

waste will remain, and any residual organic matter will be

instantly oxidized by some of the dissolved oxygen. The

nutrients are now readily available for enhancing the

prolific growth of different kinds of natural plankton that

feed the polyculture of 5 to 6 species of compatible fish.

No artificial feed is necessary, except locally grown grass

for any herbivorous fish. The fish waste, naturally treated

in the big pond, gives nutrients that are effectively used

by crops growing in the pond water and on the dykes.

 

Fermented rice or other grain, used for producing alcoholic

beverages, or silkworms and their wastes, can also be added

to the ponds as further nutrients, resulting in higher fish

and crop productivity, provided the water quality is not

affected. Trials are taking place with special diffusion

pipes carrying compressed air from biogas-operated pumps to

aerate the bottom part of the pond; to increase plankton and

fish yields.

 

Apart from growing vine-type crops on the edges of the pond

and letting them climb on trellises over the dykes and over

the water, some countries grow aquatic vegetables floating

on the water surfaces in lakes and rivers. Others grow

grains, fruits and flowers on bamboo or long-lasting

polyurethane floats over nearly half the surface of the

fishpond water without interfering with the polyculture in

the pond itself. Such aquaponic cultures have increased the

crop yields by using half of the millions of hectares of

fishponds and lakes in China. All this is possible because

of the excess nutrients created from the integrated farming

systems. It is now possible to have 4 rice crops yearly in

the warmer parts of the country, grown in floats on the

water, with almost total elimination of the back breaking

work previously required.

 

Hydroponic cultures of fruits and vegetables are also done

in a series of pipes. The final effluent from the hydroponic

cultures is polished in earthen drains where plants such as

Lemna, Azolla, Pistia and water hyacinth remove all traces

of nutrients such as nitrate, phosphate and potassium before

the purified water is released back into the aquifer.

 

The sludge from the anaerobic digester, the algae, crop and

processing residues are put into plastic bags, sterilized in

steam produced by biogas energy, and then injected with

spores for culturing high-priced mushrooms.

 

The mushroom enzymes break down the ligno-cellulose to

release the nutrients and enrich the residues, making them

more digestible and more palatable for livestock. The

remaining fibrous residues also can still be used for

culturing earthworms, which provide special protein feed for

chickens. The final residues, including the worm casting,

are composted and used for conditioning and aerating the

soil.

 

Sustainable development & human capital

 

There has been a widespread misconception that the only

alternative to the dominant model of infinite, unsustainable

growth is to have no growth at all. I have heard some

critics refer to sustainable development as a contradiction

in terms. IFWMS, however, is a marvellous demonstration that

sustainable development is possible. It also shows that the

carrying capacity of a piece of land is far from constant;

instead it depends on the mode of production, on how the use

of the land is organised. Productivity can vary three- to

four-fold or more simply by maximising internal input, and

in the process, creating more jobs, supporting more people.

The argument for population control has been somewhat over-

stated by Lester Brown [24, 25], and others predicting

massive starvation and population crash as oil runs out. I

like the idea of " human capital " , if only to restore a sense

of balance that it isn't population number as such, but the

glaring inequality of consumption and dissipation by the few

rich in the richest countries that's responsible for the

current crises. The way Cuba coped with the sudden absence

of fossil fuel, fertilizer and pesticides by implementing

organic agriculture across the nation is a case in point

[26]. Julia Wright will say more about that to-morrow. There

was no population crash; although there was indeed hardship

for a while. It also released creative energies, which

brought solutions and many accompanying ecological and

social benefits.

 

For the past 50 years, the world has opted overwhelmingly

for an industrial food system that aspired to substitute

machines and fossil fuel for human labour, towards

agriculture without farmers [27]. This has swept people off

the land and into poverty and suicide. One of the most

urgent tasks ahead is to re-integrate people into the

ecosystem. Human labour is intelligent energy, applied

precisely and with ingenuity, which is worth much more than

appears from the bald accounting in mega-Joules or any other

energy unit. This is an important area for future research.

 

Sustainable development is possible

 

Let me clarify my main message with a few diagrams. The

dominant model of infinite unsustainable growth is

represented in Figure 1. The system grows relentlessly,

swallowing up the earth's resources without end, laying

waste to everything in its path, like a hurricane. There is

no closed cycle to hold resources within, to build up stable

organised structures.

 

Figure 1. The dominant economic model of infinite

unsustainable growth that swallows up the earth's resources

and exports massive amounts of wastes and entropy

 

In contrast, a sustainable system is like an organism [15-

19], it closes the cycle to store as much as possible of the

resources inside the system, and minimise waste (see Figure

2). Closing the cycle creates at the same time a stable,

autonomous structure that is self-maintaining, self-renewing

and self-sufficient.

 

Figure 2. The sustainable system closes the energy and

resource use cycle, maximising storage and internal input

and minimising waste, rather like the life cycle of an

organism that is autonomous and self-sufficient

 

In many indigenous integrated farming systems, livestock is

incorporated to close the circle (Figure 3), thereby

minimizing external input, while maximising productivity and

minimizing wastes exported to the environment.

 

Figure 3. Integrated farming system that closes the cycle

thereby minimizing input and waste

 

The elementary integrated farm supports three lifecycles

within it, linked to one another; each lifecycle being

autonomous and self-renewing. It has the potential to grow

by incorporating yet more lifecycles (Figure 4). The more

lifecycles incorporated within the system, the greater the

productivity. That is why productivity and biodiversity

always go together [28]. Industrial monoculture, by

contrast, is the least energy efficient in terms of output

per unit of input [18], and less productive in absolute

terms despite high external inputs, as documented in recent

academic research [29].

 

Figure 4. Increasing productivity by incorporating more

lifecycles into the system

 

Actually the lifecycles are not so neatly separated, they

are linked by many inputs and outputs, so a more accurate

representation would look something like Figure 5 [15, 17,

18].

 

Figure 5. The many-fold coupled lifecycles in a highly

productive sustainable system

 

The key to sustainable development is a balanced growth

that's achieved by closing the overall production cycle,

then using the surplus nutrients and energy to support

increasingly more cycles of activities while maintaining

internal balance and nested levels of autonomy, just like a

developing organism [15, 17, 18]. The `waste' from one

production activity is resource for another, so productivity

is maximised with the minimum of input, and little waste is

exported into the environment. It is possible to have

sustainable development after all; the alternative to the

dominant model of unlimited, unsustainable growth is

balanced growth. The same principles apply to ecosystems

[19] and economic systems [17, 18] that are of necessity

embedded in the ecosystem (Figure 6).

 

Figure 6. Economic system coupled to and embedded in

ecosystem

 

Deconstructing money and the bubble economy

 

Economics immediately brings to mind money. The circulation

of money in real world economics is often equated with

energy in living systems. I have argued however, that all

money is not equal [17, 18]. The flow of money can be

associated with exchanges of real value or it can be

associated with sheer wastage and dissipation; in the former

case, money is more like energy, in the latter case, it is

pure entropy. Because the economic system depends ultimately

on the flow of resources from the ecosystem, entropic costs

can either be incurred in the economic system itself, or in

the ecosystem, but the net result is the same. Thus, when

the cost of valuable (non-renewable) ecosystem resources

consumed or destroyed are not properly taken into account,

the entropic burden falls on the ecosystem. But as the

economic system is coupled to and dependent on input from

the ecosystem, the entropic burden exported to the ecosystem

will feedback on the economic system as diminished input, so

the economic system becomes poorer in real terms.

 

On the other hand, transaction in the financial or money

market creates money that could be completely decoupled from

real value, and is pure entropy produced within the economic

system. This artificially increases purchasing power,

leading to over-consumption of ecosystem resources. The

unequal terms of trade, which continues to be imposed by the

rich countries of the North on the poor countries of the

South through the World Trade Organisation, is another

important source of entropy. That too, artificially inflates

the purchasing power of the North, resulting in yet more

destructive exploitation of the earth's ecosystem resources

in the South.

 

Recent research in the New Economics Foundation shows how

money spent with a local supplier is worth four times as

much as money spent with non-local supplier [30], which

bears out my analysis. (Maybe you'll hear more about that

from David Woodward tomorrow.) It lends support to local

currencies and the suggestion for linking energy with money

directly [31]. It also explains why growth in monetary terms

not only fails to bring real benefits to the nation, but

ends up impoverishing it [32, 33].

 

Lester Brown argues [25] that the economy must be

" restructured " at " wartime speed " by creating an " honest

market " that " tells the ecological truth " . I have provided a

sustainable growth model that shows why the dominant model

fails, and why telling the ecological truth is so important.

 

 

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