The Institute of Science in Society
Science Society Sustainability http://www.i-sis.org.uk
ISIS Press Release 29/06/05
Making the World Sustainable
Mae-Wan Ho
Biophysics Group, Dept. of Pharmacy, King’s College, Franklin-Wilkins Bldg.
Plenary lecture at Food Security in An Energy-Scarce World international conference, 23- 25 June 2005, University
College, Dublin, Ireland.
A fuller version with references and figures are posted on ISIS Members’ website.
Abstract
Decades of an "environmental bubble economy" built on the over-exploitation of natural resources has accelerated global
warming, environmental degradation, depletion of water and oil, and brought falling crop yields, precipitating a crisis
in world food security with no prospects for improvement under the business as usual scenario.
There is, nevertheless, a wealth of knowledge for making our food system sustainable that not only can provide food
security and health for all, but can also go a long way towards mitigating global warming by preventing greenhouse gas
emissions and creating new carbon stocks and sinks.
One of the most important obstacles to implementing the existing knowledge is the dominant economic model of
unrestrained, unbalanced growth that has already failed the reality test. I describe a highly productive integrated
farming system based on maximising internal input to illustrate a theory of sustainable organic growth as alternative to
the dominant model.
Current food production system due for collapse
World grain yield fell for four successive years from 2000 to 2003 as temperatures soar, bringing reserves to the lowest
in thirty years [1]. The situation did not improve despite a ‘bumper’ harvest in 2004, which was just enough to satisfy
world consumption. Experts are predicting [2] that global warming is set to do far worse damage to food production than
"even the gloomiest of previous forecasts." An international team of crop scientists from China, India, the Philippines
and the United States had already reported that crop yields fall by 10 percent for each deg. C rise in night-time
temperature during the growing season [3].
The Intergovernment Panel on Climate Change (IPCC) predicted in 2001 that the earth’s average temperature would rise by
1.4 to 5.8 deg. C within this century [4]. In 2003, a Royal Society conference in London told us that the IPCC model
fails to capture the abrupt nature of climate change, that it could be happening over a matter of decades or years [5].
In January 2005, a group based in Oxford University in the UK predicts a greater temperature rise of 1.9 to 11.5 deg. C
when carbon dioxide level in the atmosphere, currently standing at 379 parts per million, doubles its pre-industrial
level of 280 parts per million sometime within the present century [6].
The "environmental bubble economy" built on the unsustainable exploitation of our natural resources is due for collapse
[7] said Lester Brown of Earth Policy Institute. The task of turning our food production system sustainable must be
addressed at "war-time" speed.
He summarised the fallout of the environmental bubble economy succinctly [8]: "..collapsing fisheries, shrinking
forests, expanding deserts, rising CO2 levels, eroding soils, rising temperatures, falling water tables, melting
glaciers, deteriorating grasslands, rising seas, rivers that are running dry, and disappearing species."
In too many of the major food-production regions of the world, such as the bread baskets of China, India and the United
States, conventional farming practices including heavy irrigation have severely depleted the underground water [7, 8].
At the same time, world oil production may have passed its peak [9]; oil price hit a record high of US$58 a barrel on 4
April 2005, and is expected to top US$100 within two years [10]. This spells looming disaster for conventional
industrial agriculture, which is heavily dependent on both oil and water.
Our current food production system is a legacy of the high input agriculture of the green revolution, exacerbated and
promoted by agricultural policies that benefit trans-national agribusiness corporations at the expense of farmers [11,
12]. Its true costs are becoming all too clear (see Box 1).
Box 1
True costs of industrial food production system
• 1 000 tonnes of water are consumed to produce one tonne of grain [13]
• 10 energy units are spent for every energy unit of food on our dinner table [14, 15]
• Up to 1 000 energy units are used for every energy unit of processed food [16]
• 17% of the total energy use in the United States goes into food production & distribution, accounting for more than 20% of all transport within the country; this excludes energy used in import and
export [17]
• 12.5 energy units are wasted for every energy unit of food transported per thousand air-miles [18, 19]
• Current EU and WTO agricultural policies maximise food miles resulting in scandalous "food swaps" [20,
21]
• Up to 25% of CO2, 60% of CH4 and 60% of N2O in the world come from current agriculture [22]
• US$318 billion of taxpayer’s money was spent to subsidize agriculture in OECD countries in 2002, while
more than 2 billion subsistence farmers in developing countries tried to survive on $2 a day [11, 23]
• Nearly 90% of the agricultural subsidies benefit corporations and big farmers growing food for export;
while 500 family farms close down every week in the US [11]
• Subsidized surplus food dumped on developing countries creates poverty, hunger and homelessness on
massive scales [11]
Benefits of sustainable food production systems for everyone
Getting our food production sustainable is the most urgent task for humanity; it is also the key to delivering health,
mitigating global warming and saving the planet from destructive exploitation. As Gustav Best, Senior Energy Coordinator
of FAO pointed out [22], agriculture is impacted by climate change, it contributes a great deal of greenhouse gases
directly, but properly done, it goes a long way towards mitigating climate change.
The benefits of sustainable food systems are becoming evident [24] (see Box 2). There are major opportunities to reduce
energy use, to make our food system much more energy efficient, and even to extract energy through converting
agricultural wastes into rich fertilizers to increase productivity, that at the same time, reduces greenhouse gas
emissions while increasing carbon stocks and sinks.
Box 2
Some benefits of sustainable food production systems
• 2- to 7-fold energy saving on switching to low-input/organic agriculture [17, 25]
• 5 to 15% global fossil fuel emissions offset by sequestration of carbon in organically managed soil
[26]
• 5.3 to 7.6 tonnes of carbon dioxide emission disappear with every tonne of nitrogen fertilizer phased
out [27]
• Up to 258 tonnes of carbon per hectare can be stored in tropical agro-forests [28], which in addition,
sequester 6 tonnes of carbon per hectare per year [29]
• Biogas digesters provide energy and turn agricultural wastes into rich fertilizers for zero-input,
zero-emission farms [30]
• 625 thousand tonnes of carbon dioxide emissions prevented each year in Nepal through harvesting biogas
from agricultural wastes [31]
• 2- to 3-fold increase in crop yield using compost in Ethiopia, outperforming chemical fertilizers [32]
• Organic farming in the US yields comparable or better than conventional industrial farming [33, 34],
especially in times of drought [35]
• Organic farms in Europe support more birds, butterflies, beetles, bats, and wild flowers than
conventional farms [36]
• Organic foods contain more vitamins, minerals and other micronutrients, and more antioxidants than
conventionally produced foods [37-40]
• 1 000 or more community-supported farms across US and Canada bring $36m income per year directly to the
farms [41]
• £50-78m go directly into the pocket of farmers trading in some 200 established local farmers’ markets
in the UK [41]
• Buying food in local farmers’ market generates twice as much for the local economy than buying food in
supermarkets chains [42]
• Money spent with a local supplier is worth four times as much as money spent with non-local supplier
[43]
Dominant model unsustainable
There is a wealth of existing knowledge that could provide food security and health for all and significantly mitigate
global warming. Unfortunately, our elected representatives are overwhelmingly committed to the neo-liberal economic
model that created the bubble-economy in the first place. They lack the wisdom and the political will to make the
structural and policy change required for implementing the knowledge. That is why the Institute of Science in Society
(ISIS) and the Independent Science Panel (ISP) have launched a Sustainable World Global Initiative to create an
opportunity for scientists across the disciplines to join forces with all sectors of civil society in a bid to make our
food system sustainable [44]. We aim to produce a comprehensive report at the end of the year that will lay out the
existing knowledge base as well as the socioeconomic and political policy and structural changes needed to implement
sustainable food systems for all. The launch conference takes place in UK Parliament 14 July 2005
(http://www.indsp.org/SustainableWorld2ndAnnouncement.php ).
The dominant economic model glorifies competitiveness and unlimited growth involving the most dissipative and
destructive exploitation of the earth’s natural resources that have laid waste to agricultural land and impoverished
billions.
A study for the International Food Policy Research Institute reveals that each year, 10 million hectares of cropland
worldwide are abandoned due to soil erosion, and another 10 million hectares are critically damaged by salination as a
result of irrigation and/or improper drainage methods. This amounts to more than 1.3 percent of total cropland lost
annually; and replacing lost cropland accounts for 60% of the massive deforestation now taking place worldwide [45].
Clearing forests releases their massive carbon stocks to the atmosphere, turning important carbon stocks and sinks into
sources. Some estimates have placed the total carbon stock of secondary tropical forests as high as 418 tonnes of C per
hectare including soil organic carbon, and carbon is sequestered at 5 tonnes C per hectare per year [46]. Change in land
use such as this accounts for 14% of the global total greenhouse gas emission [4].
The World Health Organisation estimates that more than 3 billion people are malnourished (lacking in calories, protein,
iron, iodine and/or vitamins A, B, C, and D), of which 850 million actually suffer from hunger (protein-energy
malnutrition) [47]. The principal cause of hunger is poverty. Some 1.08 billion poor people in developing countries live
on $1 or less a day; of these, 798 million are chronically hungry.
Continued commitment to the dominant economic model – that has so glaringly failed the reality test - is perhaps the
greatest obstacle to implementing sustainable food systems. There are already many success stories from the grassroots,
and I shall describe one of them [30] briefly. It illustrates most concretely an alternative model of sustainable,
balanced growth that I have been elaborating over the past 8 years [48-51], and presented in its most definitive form
recently in collaboration with ecologist Robert Ulanowicz [52].
Environmental engineer meets Chinese peasant farmers
It may sound 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) [53]. I just call it "dream farm" [30].
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 learned from the Chinese peasants a system of farming and living that inspired him and many others including 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.
The integrated farm typically consists of crops, livestock and fishponds. But the nutrients from farm wastes often spill
over into supporting extra production of algae, chickens, earthworms, silkworms, mushrooms, and other valuables that
bring additional income and benefits for the farmers and the local communities.
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 that support the
growth of 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. All the extra nutrients go to increase productivity, which is standing carbon stock, preventing carbon dioxide
(CO2) going to the atmosphere. Biogas is used, in turn, as a clean energy source for cooking. This alone, has been a
great boon to women and children [54], above all, 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 60 to 70 lb of firewood each
week, creating spare time for studying in the evening or earning more income. Biogas energy also enables farmers to
process their produce for preservation and added value, reducing spoilage and increasing the overall benefits.
The system has revolutionized farming of livestock, aquaculture, horticulture, agro-industry and allied activities in
some countries especially in non-arid tropical and subtropical regions. It has solved most of the existing economic and
ecological problems and provided the means of production in the form of fuel, fertilizer and feed, increasing
productivity many-fold.
"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 [55].
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 [56].
Adding a second production cycle of fish and generating further nutrients from fish wastes has enhanced the integration
process, and improved the livelihoods of many small farmers considerably. But too much untreated wastes dumped directly
into the fishpond can rob the fish of oxygen, and end up killing the fish.
In IFWMS, the anaerobically digested wastes from livestock are treated aerobically before the nutrients are delivered
into the fishponds to fertilize the natural plankton that feed the fish without depleting oxygen, thereby increasing
fish yield 3- to 4-fold, especially with the polyculture of many kinds of compatible fish feeding at different trophic
levels as practiced in China, Thailand, Vietnam, India and Bangladesh. The fish produce their own wastes that are
converted naturally into nutrients for crops growing both on the water surface and on dykes surrounding the ponds.
The most significant innovation of IFWMS is thus the two-stage method of treating wastes. Livestock waste contains very
unstable organic matter that decomposes fast, consuming a lot of oxygen. So for any fish pond, the quantity of livestock
wastes that can be added is limited, as any excess will deplete the oxygen and affect the fish population adversely,
even killing them.
Chan is critical of "erratic proposals" of experts, both local and foreign, to spread livestock wastes on land to let
them rot away and hope that the small amount of residual nutrients left after tremendous losses that damage the
environment have taken place.
According to the US Environment Protection Agency, up to 70% of nitrous oxide, N2O, a powerful greenhouse gas with a
global warming potential of 280 (i.e., 280 times that of carbon dioxide) comes from conventional agriculture [57].
Nitrous oxide is formed as an intermediate both in nitrification – oxidising ammonia (NH3) into nitrate (NO3-) – and
denitrification, reducing nitrate ultimately back to nitrogen gas. Both processes are carried out by different species
of soil bacteria. Animal manure could be responsible for nearly half of the N2O emission in agriculture in Europe,
according to some estimates; the remainder coming from inorganic nitrate fertilizer [58]. Thus, anaerobic digestion not
only prevents the loss of nutrients, it could also substantially reduce greenhouse gas emissions from agriculture in the
form of both methane (harvested as biogas) and nitrous oxide (saved as nutrient).
Chan further dismisses the practice of composting nutrient-rich livestock wastes [59], for this ends up with a
low-quality fertilizer that has lost ammonia, nitrite (NO) and nitrous oxide. Instead of mixing livestock wastes with
household garbage in the compost, Chan recommends producing high-protein feeds such as earthworms from the garbage, and
using worm castings and garbage residues as better soil conditioners.
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 [60].
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.
Planting patterns have also improved. For example, rice is now transplanted into modules of 12 identical floats, one
every week, and just left to grow in the pond without having to irrigate or fertilize separately, or to do any weeding,
while it takes 12 weeks to mature. On the 13th week, the rice is harvested and the seedlings transplanted again to start
a new cycle. It is possible to have 4 rice crops yearly in the warmer parts of the country, with almost total
elimination of the back breaking work previously required.
Another example is hydroponic cultures of fruits and vegetables 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 [7, 8] and in several contributions to
the present conference predicting massive starvation and population crash as oil runs out. I like the idea of "human
capital" to counter that argument, 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 [61]. 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. 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 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 [48-52], 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 [62]. Industrial monoculture, by contrast, is the least energy efficient in terms of output per unit
of input [51], and less productive in absolute terms despite high external inputs, as documented in recent academic
research [63].
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 [49, 50, 52].
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 [49, 50, 52]. 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 [52] and economic systems [50, 51] 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 [50, 51]. 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.
It is of interest that 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 [43], which bears out my analysis. It lends support to
the idea of local currencies and the suggestion for linking energy with money directly [64]. It also explains why growth
in monetary terms not only fails to bring real benefits to the nation, but end up impoverishing it in real terms [65,
66].
Lester Brown argues [7] 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.
Acknowledgement
I am indebted to FESTA for inviting me to present a lecture at the conference, Food Security in An Energy-Scarce World,
which resulted in the present paper. It benefited a great deal from the formal presentations as well as discussions with
Richard Douthwaite, Folke Gunther, Colin Hines, Julian Darley, David Fleming, James Bruges, Bruce Darrell and numerous
others.
This article can be found on the I-SIS website at http://www.i- sis.org.uk/MTWS.php
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ENDS