1. Institute of Science in Society
www.i-sis.org.uk
Sustainable Agriculture Essential for Green Circular Economy
No attempt to build a green economy can succeed unless it is fully integrated with sustainable
primary agricultural production based on nature’s own circular economy
Dr. Mae-Wan Ho
Invited Lecture for Ten+One Conference on Closed Loop Thinking, University of Bradford,
UK, 29 November – 1 December, 2010.
China’s circular economy initiative
I first heard the term “circular economy” mentioned while on a study-lecture tour in China in
2006; after I had given a talk on my ‘zero-entropy model of organisms and sustainable systems’
[1, 2] (The Rainbow and the Worm, The Physics of Organisms, ISIS publication; Sustainable
Systems as Organisms? ISIS scientific publication) at the Guangzhou Institute of Geography
(Guangzhou, Canton Province). Prof. Zhang Hongou, director of the Institute, told me that what I
had been talking about was the “circular economy” of mainstream Chinese thinking, as opposed
to the dominant linear economy of the West.
“Circular economy” originated from a Chinese government initiative launched in 2004 to
balance economic development with the protection of environmental resources [3, 4]. The
initiative came at the end of 25 years in which China’s economy has been growing on average
8.7 percent a year, with concomitant rise in material and energy consumption. Oil imports
increased sharply, water and mineral resources were over-exploited, and environmental pollution
threatened to get out of control. Politicians and academics alike were calling for a more efficient,
circular economy.
Under the proposal from the National Development and Reform Commission (NDRC), a
circular economy would be achieved through legislative, political, technical and financial
measures; including government subsidies and tax breaks.
The initiative was targeted at the manufacturing and service business sectors, exhorting
them to enhance the economy and the environment by collaborating in managing environmental
resources, so that one facility’s waste, including energy, water, materials (as well as
information), is another’s input. By working together, “the business community seeks a
collective benefit that is larger than the sum of the individual benefits.”
The circular economy was linked to an ambitious development target to raise the majority
of China’s population into “the all-round well-being society” [4], so that by 2050, a larger
population of 1.8 billion would have per capita GDP increased five-fold to US$ 4 000 per year.
Some people think that could be achieved within the next 30 years, but would demand a sharp
rise in production, multiplying the pressures on natural resources and the environment. China’s
economy would need at least a seven-fold improvement in efficiency of resource use, or more
likely, as much as ten-fold.
In 2008, China passed the Circular Economy Law [5]: Article 1 states: “This Law is
formulated for the purpose of promoting the development of the circular economy, improving the
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2. resource utilization efficiency, protecting and improving the environment and realizing
sustainable development.” Article 2 states: “The term “circular economy” as mentioned in these
measures is a generic term for the reducing, reusing and recycling activities conducted in the
process of production, circulation and consumption.”
The Circular Economy Law is a watered-down version of the original proposal [4]. It has
no vision for reducing resource-use, or improving resource-use efficiency seven to ten-fold. It
states no goals, relying instead on incremental improvements. Furthermore, while the Law will
be managed by the powerful NDRC, the actual implementation and enforcement will be
delegated to Local Authorities that are often accused of being corrupt.
In my view, the biggest omission in China’s circular economy is not the lack of targets or
central control; it is to leave out sustainable primary agricultural production, the heart and soul of
a circular economy (see [6] Sustainable Agriculture, Green Energies and the Circular Economy,
SiS 46).
The importance of sustainable agriculture to China’s circular economy was highlighted in
two national surveys published in 2010. A first-ever national pollution census showed that
China’s intensive, high input agriculture is a worse polluter than its burgeoning industries ([7]
China's Pollution Census Triggers Green Five-Year Plan, SiS 46). Wastewater runoff from farms
accounted for 13.2 Mt of pollutants, more than one-third of the total 30.3 Mt discharged into
water in 2007. A second study uncovered significant acidification in China’s major croplands
since the 1980s as the result of the overuse of nitrogen fertilizers ([8] China’s Soils Ruined by
Overuse of Chemical Fertilizers, SiS 46). Acidification of soils reduces productivity and can lead
to aluminium and manganese toxicities.
China’s food security is precarious, as it farms only 7 percent of the world’s land to feed
22 percent of world population. Wen Tiejun, dean of the school of agriculture and rural
development at Renmin University said China does not have to rely on chemical farming, and
the government needs to foster low pollution agriculture.
China is not alone in her quest for a ‘green’ or ‘circular’ economy. Peak oil, depletion of
water, and global warming are all powerful drivers for governments including the UK to move
towards some semblance of a green economy by reducing greenhouse emissions and dependence
on fossil fuels, and increasing renewable energies. But very few governments have included
sustainable, organic agriculture in their vision of the green economy. This is a serious oversight,
especially in view of the multiple threats to food security that precipitated a world food crisis in
2008-9, which is continuing in 2010.
World food crisis and threats to food security
At the end of 2009, over one billion of the world’s population are critically hungry, with 24 000
dying of hunger each day, more than half of them children. The United Nations Food Programme
released these grim figures [9. 10] as it faced a budget shortfall of US$4.1 billion. An estimated
150 million was added to the hungry in 2008 alone; and worse was predicted for 2010 [10]. Food
prices have remained high despite the economic downturn, and extreme weather patterns
affecting production have caused more hunger. Since the middle of June 2010, prices have
increased again; global wheat prices rose 56 percent, impacting on other staples such as rice,
maize, and sorghum [11].
Many commentators rightly blame financial speculation in the global agricultural
commodities markets for precipitating the world food crisis in 2008 (see [12] Financing World
Hunger, SiS 46). However, other more serious and longer term threats to food security are in
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3. danger of being overlooked. Veteran world watcher Lester Brown reminds us that many past
civilizations collapsed on account of shrinking food supplies, and we may well meet the same
fate from [13] “our failure to deal with the environmental trends that are undermining world food
economy - most importantly falling water tables, eroding soils, and rising temperatures.”
Our industrial agriculture and food system has been showing signs of collapse [13, 14].
We have covered the topic extensively in many issues of our trend-setting magazine, Science in
Society. World grain yields are falling, or stagnating, and failing to meet demand most years
since 2000, with reserves reaching their lowest in 50 years [15, 16] (The Food Bubble Economy,
SiS 25; Sustainable World - A Global Initiative, UNEP, and SiS 26). In the major croplands of
the world – China, India and US, which contain half the world’s population, industrial farming
practices have severely depleted underground water, dried out rivers and lakes, eroded topsoil,
and decimated wild life with fertilizers and pesticides run-offs. Most alarming is the recent
disappearance of bees and other pollinators (see [17] Mystery of Disappearing Honeybees and
other articles in the series, SiS 44).
At the same time, world oil production has passed its peak [18] Oil Running Out (SiS 25)
with the peak of natural gas not far behind [19]. Conventional industrial agriculture is heavily
dependent on fossil fuels as well as water.
In addition, climate change has emerged as a major threat to agricultural productivity.
Direct field monitoring showed that crop yields fell 10 percent for each ˚C rise in night-time
temperature during the growing season [20]. The International Food Policy Research Institute
predicts that wheat yields in developing countries will drop 30 percent by 2050, while irrigated
rice yields will drop 15 percent [21]. Climate change may hit the developing world harder, but
the developed world is not immune. Increasing frequencies of drought, flood, and storm
associated with climate change will devastate crops and livestock, and spells of extreme heat are
also damaging as plants will start to deteriorate at about 32 ˚C. The yields of corn, soybeans and
cotton could fall by 30 to 46 percent under the slowest warming scenario, or 63 to 82 percent
under the fastest warming scenario.
Another major factor that precipitated the 2008 global food crisis was the scramble for
biofuels by developed nations in response to peak oil and climate change that has taken food and
land from people [22] (Biofuels and World Hunger, SiS 49). And worse, the global land-grab
[23] ‘Land Rush’ as Threats to Food Security Intensify, SiS 46) in the midst of speculation on
food commodities and the food price hike [10]; all conspiring to create world hunger on a
massive scale.
I cannot over-emphasize the importance of organic sustainable food systems for our
survival, and we need to implement that globally right now [13].
Sustainable agriculture to exit the food crisis
Only sustainable agriculture and localized food systems can take us out of the food crisis, and
overcome practically all the destructive features of industrial monoculture. Sustainable food
systems offer many synergistic benefits for tackling climate change, improving health and the
environment, and reducing poverty and inequality. The evidence is copiously documented in our
2008 report [24] (Food Futures Now: *Organic *Sustainable *Fossil Fuel Free , ISIS/TWN
report). It saves energy, water, and carbon emissions, provides resistance & resilience to climate
change, prevents pollution of the environment, increases biodiversity, (certainly saving our
bees), yields more than chemical agriculture, produces healthier food for the nation, results in
more profit (as well as independence) for farmers, creates more jobs, and when integrated with
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4. local green energies generation, forms the green circular economy we need to replace the
unsustainable economic model.
Green energies are renewable, environmentally friendly, safe, healthy, non-polluting and
sustainable, as reviewed comprehensively in a companion volume [25] Green Energies - 100%
Renewable by 2050, ISIS/TWN report). Sustainable means in the first instance to endure for
thousands of years like natural ecosystems.The world is already shifting to renewable energies,
and 100 percent green power is realistic by 2050 from available and rapidly improving
technologies. The key is decentralized distributed generation that offers maximum flexibility to
take advantage of technological improvements, giving people autonomy and independence from
obsolete, wasteful, centralized power plants.
Food Futures Now highlights
Some highlights from our Food Futures Now report will show that we can produce abundant
food organically, without fossil fuels.
Scientists reviewed 293 studies worldwide in which organic cropping is directly
compared with conventional chemical cropping. They found organic agriculture out yields
conventional by a factor of 1.3; and more than enough nitrogen can be provided by green manure
alone, amounting to 171 percent of synthetic N fertilizer used currently. They remarked that
organic agriculture can support “ a substantially larger population than currently exists.”
Coincidentally, in Tigray Ethiopia, a 7 year experiment carried out with farmers clearly
showed that composing out yields chemical fertilizers by more than 30 percent over a wide range
of soil types and rainfall.
In one of the longest running experiment comparing organic and conventional cropping at
the Rodale Institute in Pennsylvania, yields were found to be equal during normal years, but
organic far out yielded conventional during drought years because organic soils held more water
as well as other nutrients that make plants resistant to stresses. Organic soils sequester up to 4
tonnes of CO2 per hectare per year, whereas conventional soils failed to sequester any carbon.
Cuba showed the world that organic agriculture can indeed feed the country without
fossil fuels, when supplies were cut off after the breakup of the former Soviet Union; and urban
agriculture played a large role, not least because it produced fresh food locally for city people,
without having to transport over long distances.
In Sahel, Africa, local farmers defied all predictions of doom after it was hit by severe
drought in the 1980s. They pushed back the desert by cooperating in conserving water and
replanting native trees, and the trees are now creating more rain than usual.
There’s plenty more in the volume that I don’t have time to mention. You must read it for
yourself. The main message is that sustainable organic agriculture is part of nature’s circular
economy, a fertile dynamo that generates and regenerates in abundance so long as we work with
it and within it. Sustainable agriculture is essential for the truly green human economy.
Sustainable agriculture is essential for the green economy
Long before I knew anything about sustainable agriculture, I discovered that nature’s economy is
circular. It is thermodynamically optimized for maximum efficiency and minimum waste, and
that is also the ideal of a sustainable economy as I describe in detail in my book and elsewhere
[1, 2]. It is not enough for our human economy to imitate nature’s economy. We must recognize
human and natural economy as one. We need nature’s produce – food, oxygen, fresh water at the
very least, and other ecosystem services - in order to survive; and hence our human economy
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5. must be part and parcel of nature’s economy. We need to re-integrate our human economy into
the natural generative and regenerative cycles that keep organisms including human beings alive,
keep all species reproducing, and ecosystems thriving for thousands of years.
The truly green economy and thermodynamics of organisms
Contrary to what many economists assume, economy is not about the flow of money; it is about
making a living transforming and exchanging materials and energy, and is therefore closely
aligned with thermodynamics. Money is the means for the exchange of real goods and services,
and not the end of economy. Major disasters like the current financial crisis come about
ultimately because people mistake the means for the end.
The thermodynamics of the living state [1] – the science of energy and material
transformation in living organisms and sustainable systems – gives ample support to the
following features of a green, sustainable economy.
• The green economy is a renewable, closed-loop resource use model that includes
agriculture, the energy, construction, manufacturing, and service industries, as well as
finance. It is a complete way of life
• Like nature, the truly green economy maximizes diversity, reciprocity, symbiosis,
cooperation and equity; greed and inequity are unsustainable
• A truly green economy is embedded within nature’s economy
• It regards nature as the ultimate source of ‘natural capital’ (Paul Hawken’s Ecology of
Commerce [26]), which must be regenerated and indeed, increased, in order to feed all
sectors of the human economy.
Let me show you how the thermodynamics of organisms and sustainable systems
underpins the green economy in a few easy lessons.
Nature’s economy is circular
It is often said that organisms are open systems dependent on energy and material flow. Flow is
not enough; there must be capture and storage of material and energy, and ultimately, a dynamic
closure of the cycle to give a self-reproducing life cycle. That is why nature’s economy is
circular (Fig 1).
Figure 1 Nature’s circular economy of reproducing lifecycle coupled to energy flow
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6. Zero-entropy ideal
Nature’s circular economy approaches the ‘zero-entropy’ ideal. Entropy is a technical term for
waste energy and is indicative of waste and dissipation in general. The ‘zero-entropy’ ideal
means that there is little to no waste inside the system, and moreover, the waste exported to the
environment is also minimized; which makes sense, as the system depends on the environment
for input (Fig. 2). You can readily see that the zero-entropy ideal is also the ideal of the
renewable, closed loop resource use model for maximum efficiency and minimum waste. But
how is that achieved?
Figure 2 The zero-entropy ideal and the renewable closed loop resource use model for
maximum efficiency and minimum waste
Fractal structure of entangled coupled cycles
The answer is cycles, entangled and coupled cycles, and cycles within cycles, a self-similar
fractal structure that bridges all space-time scales of real processes (Fig. 3). This scale-invariant
structure is typical of organic systems and processes, and, I suggest, optimized for capturing,
storing and mobilizing resources efficiently and rapidly [27, 28] (Energy, Productivity &
Biodiversity and Why Are Organisms So Complex? SiS 21).
The structure maximizes diversity in size distribution: numerous small entities scaling up
to very few large ones. Old mature forests tend towards this ideal ‘all size’ distribution [29]
(Multiple Uses of Forests, SiS 26), and are indeed more productive and more biodiverse. It is not
just that small is beautiful; we need all sizes distributed according to an inverse power law: as
size goes up the number goes down. Such a distribution of resources that supports the greatest
diversity is also the most equitable.
Another key feature is that activities requiring energy or material are coupled to those
that generate them; and the giving and taking can be reversed as the need arises. In other words,
the system maximizes symbiosis, reciprocity and cooperation. Fair and just exchange maintains
the structure, while greed and exploitation destroys it. For the same reasons, when money
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7. becomes an end in itself and gets decoupled from real goods and services, this optimum fractal
structure is obliterated.
Figure 3 Fractal structure of entangled coupled cycles maximizes diversity, symbiosis,
reciprocity, cooperation and equity for efficient resource storage and use
AM Selvam, retired deputy director of the Indian Institute of Tropical Meteorology in
Pune, has recently proposed [30] that natural dynamical systems with self-similar space-time
structures can be represented as a “superimposition of a continuum of eddies (waves), the larger
eddies enclosing the smaller eddies, i.e., the space-time integration of enclosed smaller eddies
gives rise to formation of successively larger eddies.” He further proposed that the distribution of
eddies and the fluctuations arising from the system are a function of the golden mean τ ≈ 1.618.
Using his model, he was able to account for the year to year variability of rainfall in India and the
USA, which the conventional statistical model fails to do.
Selvam’s picture of dynamical system as a continuum of eddies resembles my diagram in
Figure 3, which I first drew in 1996. Needless to say, I am very excited by his proposal, and am
studying it carefully.
Human economy must embed itself within nature
Finally, the human economy needs to embed itself within nature’s economy, taking care that
minimum waste is exported to the ecosystem, basically because it depends on the natural
ecosystem for input (Fig. 4).
Moreover, replenishing and enriching nature’s capital also makes sense, because there is
then more input to feed all sectors of the human economy. Everyone becomes richer as a result.
We can also see why an unequal accumulation of money is damaging for the natural ecosystem
that feeds the human economy. When people are exploited by low wages, they in turn exploit the
ecosystem to make up for the shortfall from unfair exchange, resulting in diminished input into
the economy. Similarly, when people accumulate too much money, especially when too much
money is generated from financial markets, their purchasing power is artificially inflated, and
they end up over-consuming and damaging the ecosystem, resulting in more diminished input
into the economy. And everyone becomes poorer in real terms as a result.
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8. Figure 4 Green human economy embeds itself in nature’s economy
Sustainable agriculture operates on closed loop principles
Sustainable agriculture has been proven all over the world, and the key to its success is the same
closed loop resource use model. The main reason for my study-lecture tour in China was coming
across octogenarian environmental engineer George Chan’s Integrated Food and Waste
Management System. I schematized it and called it ‘Dream Farm’ (Fig. 5), because it is an
abundantly productive farm with diverse crops, livestock and fish ponds, built around the
anaerobic digestion of livestock and other organic wastes to regenerate resources and recycle
nutrients, the biogas produced in the process satisfying energy needs [31]( Dream Farms, SiS27).
Figure 5 George Chan’s Integrated Food and Waste Management System
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9. George Chan has some lovely pictures of farms he helped set up around the world, but
alas, very little real data.
George Chan, in turn, learned from the Chinese peasants who perfected the dyke-pond
system of Pearl River Delta that I was able to visit in 2006 [32] (Circular Economy of the Dyke-
Pond System, SiS 32). There are many dyke-pond systems that work with the circular economy
of nature. They are so productive that the delta supported 17 people per hectare in its heyday, the
kind of productivity that China needs. This shows you how misleading it is to assume there is a
fixed carrying capacity associated with a piece of land. It depends on how it is managed. In one
version, pigs, elephant grass, mulberry and silkworms are raised on the dykes, the wastes and
elephant grass go to feed up to 5 species of carp in the ponds. The pond water is used to
‘fertigate’ the crops on the dykes, and pond mud used as additional fertilizer. This is nothing but
a skilful application of the closed looped resource use model over and over again.
The old Chinese professors from Guangzhou Institute of Geography who had studied and
documented the productivity of the dyke-ponds in the 1980s came with us to revisit the region.
The dyke-ponds are very much in decline, overtaken by industrial development. But we were
still able to see vestiges of old systems, and there are efforts to recreate agro-ecological fish
farms based on some of the old practices.
Anaerobic digestion
Anaerobic digestion of organic wastes is clearly the core of the circular economy. It turns wastes
into green energy resources, saving carbon emissions twice over, by preventing escape of
methane, and substituting for fossil fuels. Methane can be used for cooking, generating
electricity and upgraded to give by far the cleanest fuel for vehicles and farm machinery.
Anaerobic digestion also effectively recycles nutrients such as nitrates and phosphates within the
system, preventing pollution of the environment. The residue and slurry are both rich in nutrients
and excellent as fertilizer and soil conditioner. Importantly, anaerobic digestion can conserve and
restore water resources. Grey and soiled water that has been used for cleaning and flushing is
cleansed and purified of 90 percent or more of dissolved contaminants and bacteria before it is
returned to the environment, or used to water and feed crops.
China has been supporting anaerobic digestion for industry and rural households since
2003. However, its use on farms is still quite limited. There is abundant feedstock for biogas
digestion in rural China, in the form of livestock and poultry manure - mostly from cattle, pigs
and chicken - and agricultural residues. I have calculated and updated the potentials for
anaerobic digestion for saving greenhouse emissions and energy.
The total physical quantity of dry excrement resource in China at last census (2007) was
1 467 million tonnes of which 1 023 million tonnes could be collected, equivalent to 107Mt of
coal (~3.1244 EJ).
Anaerobic digestion could include human manure (traditionally used as crop fertilizer in
China). Agriculture is estimated to employ 40.8 percent of the population. Anaerobic digestion
of the wastes from 40.8 percent of 1.4 billion (571 million) would yield 2.0168 Mt of methane or
0.112 EJ energy.
Straw is abundant and exploited for many uses in China, including a high proportion
that’s burned for energy, some 290 million tonnes; which, on anaerobic digestion, would yield
methane equivalent to 4.234 EJ.
Thus, the total potential energy saving from anaerobic digestion of livestock and human
wastes and straw amount to 7.47 EJ, or 10.35 percent of national energy consumed.
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10. In terms of carbon savings, it is also very impressive. From livestock manure emission
figures [33] and manure production figures [34] given for China. An estimated 10 percent of the
methane harvested by anaerobic digestion would have been emitted by the manure if untreated;
and approximately half of that emission (5 percent) is mitigated by anaerobic digestion.
Consequently, the methane prevented is 2.81 Mt, equivalent to 70 Mt CO2 (at global warming
potential of 25 over 100 years). In addition, the 7.47 EJ of fossil fuel not used (by biogas
methane substitution) translates into a saving of 516 Mt CO2e. The total saving of carbon
emissions from anaerobic digestion of livestock and human manure and straw is 586 Mt, or 7.79
percent of national emissions.
Table 1 gives the summary of the carbon and energy savings from organic agriculture in
China [6] and the current update on the savings from anaerobic digestion.
I am using China as an example, because of the good national statistics available; but the
estimates are very similar for other countries, such as the UK [35] (Organic Agriculture and
Localized Food & Energy Systems for Mitigating Climate Change, SiS 40).
Table 1 Green potential of organic agriculture and anaerobic digestion
CO2e savings (% National) Energy savings (% National)
Organic agriculture
N fertilizers saving 179.5 Mt ( 2.38%) 2.608 EJ ( 3.61%)
N2O prevented 92.7 Mt ( 1.23%)
Carbon sequestration 682.9 Mt ( 9.07%)
Total for org. agri. 955.1 Mt (12.69%) 2.608 EJ ( 3.61%)
Anaerobic digestion
Livestock manure ghg saving 70.3 Mt ( 0.09%)
methane produced 215.5 Mt ( 2.86%) 3.124 EJ ( 4.33%)
Hum manure methane 7.7 Mt ( 0.10%) 0.112 EJ ( 0.16%)
Straw methane 292.5 Mt ( 3.93%) 4.234 EJ ( 5.86%)
Total for AD 586.0 Mt ( 7.79%) 7.470 EJ ( 10.35%)
Total overall 1 491.1 Mt (20.48%) 10.078 EJ (13.96%)
As can be seen, the combination of organic agriculture and anaerobic digestion in China
has the potential to mitigate at least 20 percent of national greenhouse gas emissions and save 14
percent of energy consumption. We can do even better.
Implementing the circular economy with green energies and sustainable agriculture
I have proposed a Dream Farm 2 (see Fig. 6) which, in addition to anaerobic digestion, explicitly
incorporates green energies at small to micro-scale (and include permanent pastures and
woodlands) [36]. This mix of energies not only ensures a reliable supply, but can reduce energy
use by at least 30 percent through exploiting ‘waste’ heat from power generation, and preventing
energy loss in long distance distribution and transmission.
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11. Figure 6 Dream Farm 2
The diagram is colour-coded. Pink is for energy, green for agricultural produce, blue is
for water conservation and flood control, black is waste in the ordinary sense of the word, which
soon gets converted into food and energy resources. Purple is for education and research into
new science and technologies. This is my private Dream Farm, complete with laboratory
facilities as well as a gourmet restaurant to take advantage of all the lovely fresh produce. It is an
excellent project for a University like Bradford, because engineers, architects, scientists, artists,
sociologists and business can all work together across the disciplines to realise the closed loop
model in design, architecture, marketing, etc, while providing huge opportunities for education,
research and innovation.
Approximately 57 percent of China’s carbon emissions come from the energy sector [6].
An efficiency saving of 30 percent would mean a reduction of 17.1 percent in carbon emissions.
The green potential of Dream Farm 2 is given in Table 2. As can be seen, Dream Farm 2, if
generally adopted in China, would mitigate 38 percent of greenhouse emissions, and save 44
percent of energy consumption, only counting anaerobic digestion.
So, with the addition of solar, wind or micro-hydroelectric as appropriate, such farms
could compensate, in the best case scenario, for the carbon emissions and energy consumption of
the entire nation. Surplus energy from the farm can go to supply homes and businesses nearby.
At the very least, such integrated food and energy farms will give us food security while playing
its part along with other sectors of the circular economy in cutting its own carbon footprint and
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12. fossil fuel use to zero. Apart from the circular economy, the success of Dream Farm 2 depends in
large measure to efficiency savings from local production and consumption for both food and
energy.
Table 2 Green potential of Dream Farm 2
CO2e savings (% National) Energy savings (% National)
Organic agriculture 955.1 Mt (12.69%) 2.608 EJ ( 3.61%)
Anaerobic digestion 586.0 Mt ( 7.79%) 7.470 EJ (10.35%)
Energy savings local gen. 1 287.1 Mt (17.10%) 21.660 EJ (30.00%)
Total 2 828.2 Mt (37.58%) 31.738 EJ (43.96%)
Circular economy of the organism and sustainable systems
Let me conclude by reinforcing the concept of circular economy in sustainable agriculture.
When you transform linear into circular, you turn output into input again; you end up
conserving energy and resources and the system renews itself (Fig. 7).
Figure 7 From linear to circular economy
The zero-entropy ideal of the organism depends on coupled cycles of activities at every
scale; thereby minimizing the dissipation of energy and materials, and even the wastes exported
to the environment is minimized. Sustainable agricultural systems work precisely in the same
way (Fig. 8). Lots of life cycles are coupled together, and the ‘wastes’ of one organism is
nutrient for another. As you can see, more lifecycles can be added into the system to make it
bigger, provided these lifecycles are linked by reciprocity and cooperation. The more lifecycles
there are, the greater the biodiversity; the more biodiverse, the more productive the system.
Contrary to the belief of some in the environmental movement, sustainable development is
possible; it is not an oxymoron. It depends on balanced growth at every stage by linking up more
cycles of reciprocity and cooperation. This is also a model for industrial processes.
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13. Figure 8 The circular economy of organisms and sustainable agriculture
The green economy (Fig. 9, top) contrasts strongly with the dominant brown economy
(Fig. 9, bottom).
Figure 9 The green versus the brown economy
The brown economy is based on infinite growth fuelled by maximum dissipation and
exploitation of people and planet. It does not close the circle to build up structure or dynamic
cycles. Boom and bust are inherent to the brown economy, so financial collapse is nothing new.
More seriously, it has destroyed the earth’s habitats and brought us climate change.
The circular green economy is built on reciprocity, cooperation and equity. It closes
circles and builds balanced dynamic structures that sustain the whole, and enables us to thrive in
balance with the earth ecosystem in which the green economy is embedded.
I hope I have gone some way in convincing you that we should have no hesitation to opt
for the thoroughly green, circular economy right away.
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14. References
1. Ho MW. The Rainbow and the Worm, the Physics of Organisms, World Scientific,
Singapore, and London, 1993, 2nd ed, 1998, reprinted 1999, 2000, 2002, 2004, 2006; 3rd
enlarged ed, 2008.
2. Ho MW and Ulanowicz R. Sustainable systems as organisms? BioSystems 2005, 82, 39-
51.
3. Hawken P. The Ecology of Commerce, Harper Collins, New York, 1994.
4. “Approaching circular economy”, Zhang Jianyu, China Daily, 1 October 2004,
http://www.chinadaily.com.cn/english/doc/2004-10/01/content_379348.htm
5. China seeks to develop a circular economy, Indigo Development, accessed 10 November
2010, http://www.indigodev.com/Circular1.html
6. Circular Economy Law of the People’s Republic of China, 29 August 2008,
http://www.chinaenvironmentallaw.com/wp-content/uploads/2008/09/circular-economy-
law-cn-en-final.pdf
7. Ho MW. China’s pollution census triggers green five-year plan. Science in Society 46,
7+13, 2010.
8. Ho MW. China’s soils ruined by overuse of chemical fertilizers. Science in Society 46, 6-
7, 2010.
9. “World food aid at 20-year low, 1 billion hungry-WFP”, Reuters, 16 September 2009,
http://www.reuters.com/article/idUSLF132356
10. “The global food crisis. More than one billion people affected by world food shortages”,
Angela Higbee, suite101.com, 9 November 2009, http://world-
hunger.suite101.com/article.cfm/the_global_food_crisis_part_1
11. World Food Price Watch, World Bank, September 2010,
http://siteresources.worldbank.org/INTPOVERTY/Resources/335642-
1210859591030/Food_Price_Watch_September2010.pdf
12. Ho MW and Saunder PT. Financing world hunger. From the Editors, Science in Society
46, 2-3, 2010.
13. Brown L. The geopolitics of food scarcity. Spiegel Online International 2 November
2009, http://www.spiegel.de/international/world/0,1518,606937,00.html
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Lim LC, et al. Food Futures Now, Organic, Sustainable, Fossil Fuel Free, ISIS/TWN,
London/Penang, 2008, http://www.i-sis.org.uk/foodFutures.php
15. Ho MW. The food bubble economy. Science in Society 25, 48-49, 2005.
16. Ho MW. Sustainable world – a global initiative. Division for sustainable Development,
UNEP,
http://webapps01.un.org/dsd/scp/public/presentProgrammeDetails.do;jsessionid=C88E02
9469896025576AB5ABF21EFFCF?progID=470; also Science in Society 26, 9, 2005.
17. Ho MW and Cummins J. Mystery of disappearing honeybees. Science in Society 34, 35-
36, 2007.
18. Ho MW. Oil running out? Science in Society 25, 50-51, 2005.
19. Darley J. High Noon for Natural Gas, Chelsea Green Publishing Company, Vermont,
2004.
20. Peng S, Huang J, Sheehy JE, LazAa RC, Visperas RM, Zhong X, Centeno GS, Khush GS
and Cassman KG, Rice yields decline with higher night temperatures from global
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dyn/content/article/2009/10/13/AR2009101300419.html
22. Ho MW. Biofuels and world hunger. Science in Society 49 (to appear).
23. Ho MW. ‘Land rush’ as threats to food security intensify. Science in Society 46, 42-46,
2010.
24. Ho MW, Burcher S, Lim LC, et al. Food Futures Now, Organic, Sustainable, Fossil Fuel
Free, ISIS/TWN, London/Penang, 2008, http://www.i-sis.org.uk/foodFutures.php
25. Ho MW, Cherry B, Burcher S and Saunders PT. Green Energies, 100% Renewables by
2050, ISIS/TWN, London/Penang, 2009, http://www.i-sis.org.uk/GreenEnergies.php
26. Hawken P. The Ecology of Commerce, Harper Collins,n New York, 1993.
27. Ho MW. Energy, productivity & biodiversity. Science in Society 21, 48-49, 2004.
28. Ho MW. Why are organisms so complex? A lesson in sustainability. Science in Society
21, 50-51, 2004.
29. Ho MW. Multiple uses of forests. Science in Society 26, 18-19, 2005.
30. Selvam AM. Universal inverse power-law distribution for fractal fluctuations in
dynamical systems: applications for predictability of inter-annual variability of indian and
USA region rainfall. http://arxiv.org/ftp/arxiv/papers/1002/1002.3230.pdf
31. Ho MW. Dream farms. Science in Society 27, 26-28, 2005.
32. Ho MW. Circular economy of the dyke-pond system. Science in Society 32, 38-41, 2006.
33. Hou J, Xie Y, Wang F, and Dong R. Greenhouse gas emissions from livestock waste;
China evaluation. International Congress Series 1293, 2006, 29-32.
34. Chen Y, Yan G, Sweeney S and Feng Y. Household biogas use in rural China: A study of
opportunities and constraints. Renewable and Sustainable Energy Reviews 2010, 14, 545-
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35. Ho MW. Organic agriculture and localiozed food & energy systems for mitigating
climate change. Science in Society 40, 24-28, 2008.
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