Science in Society Archive

Closed Loop, Cradle to Cradle, Circular Economy & the New Naturephilia

A new-found love of nature is shared by leaders of sustainable development and their ideas are beginning to find favour in the corridors of power Dr. Mae-Wan Ho

Closed loop Europe

When Belgium took over the Presidency of the European Union (EU) in July 2010, Flemish Environment Minister Joke Schauvliege became President of the EU’s Environment Council and lost no time in placing sustainable “closed loop” resource management at the top of her agenda  She said: [1] “We must deal with our materials, and with our energy, more efficiently. At the end of their life we must be able to reuse materials as new raw materials. This is called completing the cycle.” 

Schauvliege was out to convince Europe about this “cradle to cradle” approach to using resources. The Dutch government has already embraced it [2], though not to the extent of legislating on it. The Chinese government has proposed a “circular economy” initiative in 2004, which became the Circular Economy Law in 2008 [3] (see Sustainable Agriculture Essential for Green Circular Economy, I-SIS Lecture).

Slogans are great for spreading ideas and creating social movements; but they are also excuses for woolly thinking and sparking points for sterile debates. “Circular economy”, “closed loop” and “cradle to cradle” have suddenly become fashionable in the corridors of power decades after they’ve been invented and re-invented. But do they refer to the same approach? And does it matter?

Fortunately, I had the opportunity to go behind the slogans to get an insight into what’s really involved.  

The Ellen Macarthur Foundation and Bradford University jointly organised a conference Ten+One (29 November -1 December 2010) [4], billed as “a masterclass for business and education leaders.”  It brought together an international panel of ten keynote speakers who have been working independently on different aspects related to the closed loop approach, presumably converging on the ‘One’ perspective of Michael Braungart, a professor of chemistry at Erasmus University, The Netherlands, who co-authored the international bestseller Cradle to Cradle with architect William McDonough, first published in 2002 [5].  

The new-found love of nature

I must confess not to have read the book before the conference and was largely unaware of what many of the other speakers have been doing, and I was not alone.  But by the end of the conference (cut short due to adverse weather conditions) I was truly inspired. A common bond that joins us all (including most of the 150 attending at the venue and others participating online) is a new-found love of nature, a desire to imitate nature’s ways of cycling and recycling materials, and a passion for working effectively with and within nature.  So it doesn’t really matter what you call it.

Each of us has created individual narratives in different words and languages, focussing on specific or more general aspects according to our experiences, but the result is a grand confluence of dreams, visions, and knowledge that could enable us to build a better world for all.

Ellen Macarthur Foundation and circular economy

Dame Ellen Macarthur is well known as the woman who sailed around the globe single-handedly in 2005 breaking the world record. She explained in an opening speech that while on her circumnavigation, she had to be very careful to make her supplies last; and it occurred to her not long afterwards that the same was true for our use of the world’s finite and dwindling resources. From that moment on, she was determined to dedicate her time to making the world sustainable. The ‘race’ to save the world is a far greater challenge. The Ellen Macarthur Foundation was launched in September 2010 as an education charity “to inspire people to re-think, re-design and build a sustainable low carbon future”; it also coincided with the publication of Ellen Macarthur’s autobiography [6]. There is a superb video of Dame Ellen speaking on the “circular economy” on the Foundation website [7], as well as informative supporting texts [8]. The Ten+One conference was the Foundation’s first official public event.

Cradle to cradle, re-designing industry to be good

Walter Stahel, an architect, economist, and one of the founding fathers of industrial sustainability is credited with having coined the expression “cradle to cradle” in the late 1970s [8]; even though Braungart and McDonough claimed to have invented it [9]. Stahel intended to reverse the crude and wasteful linear industrial system the world has inherited from the industrial revolution, which depletes finite resources, creating toxic products that largely end up in landfills to poison the environment.  Stahel developed a “closed loop” approach to production and founded the Product Life Institute in Geneva with the main goals of product-life extension, long-life goods, reconditioning activities and waste prevention. Kodak, DuPont, the BBC and Bosch are among its clients.

“Cradle to cradle” as propounded by Braungart and McDonough means to go one step further; they want industry not only to close the loop by recycling, but to redesign the industrial processes altogether. Instead of concentrating on making the current system more efficient (less bad), we can redesign the system to be thoroughly good. Recycling and reuse is not a solution if the product or material is toxic in the first place, it will inevitably end up in the environment to poison us more slowly, but still surely.

So, we must eliminate toxic materials and processes altogether, to make products that can be safely recycled and reused or else composted to support plant growth. There are already impressive successes (but also notable failures that critics accuse McDonough of ignoring, or still claiming as successes [9]).

If, like me, you expected to find a coherent theory behind the cradle to cradle approach, then you’d be disappointed and frustrated as I was, until I learned of the successful actual implementations (see Box), which serve to remind us that good intentions can often work. On the other hand, a coherent theory may improve the success rate, and at least, provide criteria for judging success.

Cradle to cradle is a set of (evolving) design principles [10] based largely on good intentions:

  • The technical cycle of manufacturing industry should mimic the biological cycle of metabolism and ecology, though somewhat separate from it
  • Technical nutrients such as metals, plastics, and other non-compostable materials should circulate from user (consumer) to manufacturer, with as much renewable energy use as possible
  • Recycle and reuse all finite resources
  • Diversity is strength (buffers against external shocks)
  • Prices must tell the truth about externally costs
  • Systems thinking is key
  • It should serve equity, economy, and ecology [11].
  • Companies currently subscribing or aspiring to the cradle to cradle approach include Aveda and B&Q.

Companies currently subscribing or aspiring to the cradle to cradle approach include Aveda and B&Q.

Aveda, a cosmetics company was founded 30 years ago by a hair-dresser who wanted to make his profession more environmentally friendly and healthy, concentrating on organically grown plant products. It gained cradle to cradle endorsement in 2009, though Chuck Bennett, who spoke for the company at the conference, readily admitted that they are not completely cradle to cradle compliant [12]. The company has many indigenous peoples as partners, and contributed more than £650 000 to programmes supporting indigenous communities and preserving their cultures and environments. It helped the Yanomami People of Venezuela gain land rights to 174 800 ha.

B&Q is a UK-based DIY company selling 35 000 products, so adopting the cradle to cradle approach not only seems an impossible dream, as you have to deal with 1 200 different suppliers, which have their own suppliers in turn; but also, as Matt Saxton, Director of Social Responsibility, points out [13], “fundamentally at odds with the business model”: to sell as many products as possible in the shortest time.  Nevertheless, they have made a start: with responsibly sourced wood products, green targets and objectives linked to pay and bonuses, and promoting an eco-range of products that reached 10 percent of sales in three years. Another initiative is to eliminate waste. Saxton is particularly proud of the re-useable and recyclable carrier pack that replaced the disposable cardboard version, resulting in massive reduction of damage and increased ease of packing. One of their current suppliers is a small company that gives old paints new life, an example of up-cycling. There are numerous innovations out there, Sexton said, for example, polystyrene packing that can be compressed into deck boards, and bio-boards made from waste agricultural products such as wheat stalks and rice husks, but “we need lots collaboration.”

“Cradle to cradle” clearly works as a slogan that people can relate to and rally round. Ironically, McDonough and Braungart are asserting proprietary rights over the slogan so others can’t use it, and refusing to open up the database on toxic chemicals to the public as they had promised years ago, or to make the C2C (short for cradle to cradle) certification transparent. As one disenchanted supporter said of McDonough [14]: “His impressive gains are frustrated by his personal desire for wealth – Cradle to Cradle had incredible potential until he slapped on such high .. licensing fees. By attempting to control and own everything he created, potential partners were alienated and the growth of his ideas stagnated.”

Fortunately, the green movement is strong and has been gaining ground independently of McDonough and Braungart or the cradle to cradle trademark they claim as their own.

I became quite excited by what I heard and read about cradle and cradle since the conference, especially in the way it converges and dovetails with my own theory of organisms and sustainable systems based almost entirely on thermodynamic considerations [3] and developed independently of the cradle to cradle approach.  Great ideas are generally discovered and rediscovered over and over again; and I see no need to claim originality or propriety.

Cradle to cradle successes

Green roofs for Ford Motor Company
The cradle to cradle approach sets out to imitate nature, and also involves enlisting the help of nature where appropriate, as in the redesign of Ford Motor Company’s River Rouge Complex in Michigan with 16 million square feet of factory floor space [15]. McDonough, through his architecture company, signed a contract with the car manufacturer and quickly recommended a green roof for the whole plant. This did not go down well at first. But then the US Environmental Protection Agency was developing new storm water regulations, and Ford had estimated that the new rules could cost almost $50 million to comply. The natural storm water management provided by the green roof cost just $15 million, with the landscape thrown in for free. The company was won over.

“Within five days of completion, birds had colonised the green roof,” said Braungart.

Biodegradable textiles good enough to eat
Swiss firm Rohner produces the Climatex Lifecycle biodegradable fabric, used extensively in the office furniture manufacturing business [16]. The fabric is designed to be “safe enough to eat” and can be composted at the end of its life.

They started out by asking various suppliers for the composition of their ingredients (especially dyes) in order to assess their toxicity. At first the suppliers were reluctant to divulge commercial secrets, but then Ciba-Geigy finally agreed to play the game. Out of the 8 000 ingredients analysed only 16 passed the test, but that was enough to create the new fabric line, after overcoming further hurdles.  

Climatex went into production and the regulators inspecting the factory were reported to have been “astounded” that the water coming out of the factory was “as clean or cleaner than the water coming in from the town’s drinking water supply sources.” By 2002, Climatex Lifecycle accounted for a third of Rohner’s approximately $8 million revenue. Waste disposal costs were drastically reduced because Rohner no longer had to pay to send trimmings to be burnt at a Swiss-regulated incinerator or to Spain. Instead, scraps were turned into a felt-like material and sold to local farmers and gardeners for use as mulch or groundcover. Overall costs were reduced, having eliminated the need for filtering dyes and chemicals in the production process. Additional bonuses came from the elimination of regulatory paperwork and freeing up space that had been used for storing hazardous chemicals.

Surprisingly, the company decided to share its most valuable asset by allowing the entire fabric industry to use the Climatex Lifecycle production process! Bonnie Sonnenschein, corporate marketing manager for DesignTex (which had invested in the project) explained: “It had been seven years since we developed Climatex Lifecycle, and in that time, to our knowledge, no one else developed a 100% safely biodegradable fabric, although there was a big interest in it. It’s not really green thinking if we just hold that information secret. It’s a good product that everyone should use.”

Re-usable carpet tiles
Stef Kranendijk, CEO of Desso, one of Europe’s leading carpet tiles manufacturers, decided his company would fully close the loop by 2020 [17]. The cradle to cradle approach, he said, is “good for people and the planet,” and “also very good for business.”

Some 600 000 tonnes of floor covering material are thrown away each year in the UK, and only 1 percent of that is recycled.

Already a convert to sustainability in 2007, the company consumed 30 percent less energy than 10 years ago, 95 percent of its industrial waste is recycled, and it is very proactive in reducing water consumption.

Then Kranendijk became aware of cradle to cradle, and realised he could go much further. He made contact with Braungart, and carried out a MDBC (McDonough Braungart Chemistry) analysis.

“We’ve moved on faster than I expected and we’re already capable of offering almost 100% Cradle to Cradle carpet tiles made from pure materials that are safely up-cyclable.” Kranendijk said.

Up-cycling is a key concept in the cradle to cradle approach, as opposed to down-cycling into inferior products that inevitably end in landfills. Up-cycling needs a product design that contains non-toxic and biodegradable material in the first place, and a process that allows for up-cycling.

The yarn of these carpet tiles will be depolymerised into caprolactam (a liquid normally made from virgin oil, from which high value plastics can be made, including new yarn). The backing material is bitumen-based. Bitumen is not as bad as PVC (which can only be de-cycled), but still not good. So Desso developed a polyolefin (a polymer of olefin with general chemical formula CnH2n) that satisfies the cradle to cradle criteria; a bit more expensive, “but 6, 8 or 10 years from now we’ll be able to recuperate and reuse it safely.” Kranendijk said.

Over the past 2 years, Desso developed unique equipment that processes old tiles, separating the yarn, which goes to a supplier that has decided to follow the movement and invested in a de-polymerisation facility to make new yarn from the old. For the tiles that still include bitumen, the material is separated and goes into road works, cycle paths, and raw material for the cement industry.

In future, when Desso takes back the polyolefin-backed tiles, the tile backing will become tile backing again. At the moment, in Germany old floor covering material is incinerated or becomes fuel for power plants, but in the UK and France, the stuff just goes to landfill. So Desso’s take-back programme should have a tremendous impact there. “The idea is to become a service industry, relying on a leasing system,” Kranendijk explained, “then you don’t buy the product, you only pay for its use, which means materials remain our responsibility and of course it’s not our interest to see them wasted, at the end everybody wins.”

Green chemistry UK

Professor James Clark heads the Green Chemistry Centre of Excellence, York University, and is a founding director of the UK-based Green Chemistry Network. True to the closed loop approach, Clark proposes to use waste as a feedstock for ‘biorefineries’ [18, 19] Green Chemistry from Wastes (SiS 49); thereby reversing the trend in the chemical industries that generate enormous amounts of often toxic wastes to the land, water and air, which vastly exceed the amounts of products made. The pharmaceutical industry, for example, wastes 99 percent of its materials.

The food industry and our consumption pattern is no better. Approximately 90 percent of primary agricultural production is wasted. Systems-thinking puts the two together in biorefineries. For example, many plants are good at scavenging heavy metals that end up in landfills, so the metals can be recovered and the land cleaned up.  A growing list of metals used in the electronics, solar panels, and other industries, such as indium, gallium, antimony, rhodium, germanium, tin, gold and silver are being depleted and crying out for recovery and reuse.

Plants also produce a host of valuable complex chemicals that can be extracted for use to replace toxic petrochemicals. A polysaccharide-based carpet adhesive is safe, bio-degradable, and acts as a flame-retardant. Rice husks, wheat straws and so on can be turned into tiles or other building materials. Currently they are being burnt, or pyrolysed, which is the wrong way around, as this breaks valuable compounds back into simple substances. “Nature is very good at building complex molecules.” Clark said, and we should use as many of them as we can instead of wasting them, or breaking them down again.

Positive development through the built environment

Janis Birkeland, artist, architect, planner, urban designer, attorney, author of Positive Development [20] and Professor of Architecture at Queensland University of Technology, is convinced that human-designed systems and developments cause much of the disasters that we blame nature for [21].  Floods, fires, landslides, urban heat island, drought, malnutrition, malaria, poor indoor air quality, and so on, are exacerbated by our ‘industrial’ (fossil-fuel-driven) systems like manufacturing, construction, agriculture and transportation.

Current system designs actually drive consumption. Cities, in particular, are responsible for 75 percent of greenhouse emissions and buildings use 40 percent of energy. Our cities are designed to lock people into unsustainable consumption.

The solution, Birkeland emphasizes, is not to build new ‘green buildings’, but to eco-retrofit cities or renovate buildings and infrastructure with natural systems and technologies that provide urban ecosystem services: clean air, heat, water, soil and food. We can use them to replace harmful fossil-fuel based equipment, provide passive solar cooling, lighting, heating and ventilating.

Positive development simply involves integrating the virtually free services of nature with development to increase the ecological base; and it can be done by using many existing green technologies, such as aquaponics, permaculture, vertical landscapes, living roofs, walls, balconies, and atria. Empty, disused warehouses, for example, could be turned into vertical ecosystems that produce food.


Biomimicry, the science of imitating nature’s designs, and listening to what she teaches us, is perhaps the most explicitly naturephile approach. Science journalist and author Janine M. Benyus gave it a name in a best-selling book entitled: Biomimicry, Innvations Inspired by Nature, first published in 1997 [22].

Chris Allen, a speaker from the Institute of Biomimicry, gave many specific examples of designs inspired by nature [23]. A ventilation system for a high-rise Eastgate Centre in Harare, Zimbabwe patterned after the ventilation system of a termite nest saves 10 percent of energy to air-condition. The flippers of the humpback whale decorated with tubercles (bumps) are responsible for the animal’s agility in water; turbine blades with tubercles on the leading edge promise greater efficiency for wind turbines, hydroelectric turbines, irrigation pumps and ventilation fans, by reducing drag and increasing lift. The surface of lotus leaves are covered with tiny bumps that cause water to form beads and roll around, picking up dust and other contaminates. This has inspired self-cleaning surfaces and coatings. The shape of the kingfisher’s beak, which allows it to dart through water without creating turbulence and frightening the fish, inspired the head of the bullet train.

Biomimicry entails the ethos of emulating and also reconnecting to life’s principles, and a corresponding value structure. There is a “vast frontier of well-adapted innovations,” Allen said.

Green education

Peter Hopkinson, Director of Education for Sustainable Development at University of Bradford, and Ken Webster, Head of Learning at Ellen Macarthur Foundation consider it most important to move from the mechanistic perspective that puts people outside nature to the one required by sustainability, that places people firmly within nature [24]. It is the age-old opposition between mechanism and organism, between the reductionists seeing the world bottom up and the holists seeing it top-down, the analytical approach of breaking things to bits versus the intuitive synthetic approach of relating and connecting.

Having come from a cultural tradition that Joseph Needham, renowned biochemist turned historian of Chinese science, quite aptly described as “organic materialism” [25], I derived untold benefits from that most rational, logical positivist Greek tradition, in the form of Euclidean geometry, which I adored more than any other subject in school. It has enabled me to use all of my faculties simultaneously. That, to me is really what’s missing from our education system that separates art from science, thinking from doing, reason from intuition.

An exciting venture in Bradford University, which has already won a prize for its education programme in sustainability, is its plan for an ‘Ecoversity’ that will be housed in a building exemplifying closed loop use of local resources.

Theory of organisms and sustainable systems

For my part, I stressed that sustainable closed loop agriculture is essential to the circular economy [3], and also presented my ‘zero-entropy’ model as the theoretical basis for nature’s circular economy and all closed loop sustainable systems, based on (non-equilibrium) thermodynamics (see [26] The Rainbow and the Worm, The Physics of Organisms, I-SIS publication), the science of material and energy transformation in nature. As such, the theory applies to physics, chemistry and biology, and hence, to both the technology cycle of the manufacturing industry (in the cradle to cradle approach) and the cycles of the living world. But most of all, the transformation of material and energy is closely aligned with economics. Contrary what most economists think, the economy is not about the flow of money; it is about transforming material and energy to make a living, which is nothing if not thermodynamics. Money is the means for the exchange of real goods and services, and it must reflect the real values of goods and services. And problems - such as the current financial crisis – arise when money is decoupled from the real values of goods and services, and most of all, when people mistake the means for the end.

The circular economy of nature is optimised to produce minimum wastes, to store the maximum amount of material, and to mobilise materials and energy most efficiently, hence the ‘zero- entropy’ ideal. It depends on a self-similar fractal circular structure (circles within circles within circles), that is perhaps the most equitable and diverse distribution of resources: many small cycles scaling up according to an inverse power law to very few large ones. This fractal ‘all size’ distribution is typical of organic structures such as the branching of trees, as well as processes such as the variability of the healthy heartbeat [27] (The Heartbeat of Health, SiS 35). Furthermore, the cycles are coupled together in a symmetrical, cooperative give-and-take that enables resources to be efficiently diverted up and down the scales to where it is most needed.

The model explains why human ideals such as equity, just exchange (being fair) and cooperation are important to the green circular economy, why biodiversity is essential in maximising reciprocities and symbiotic relationships, why biodiverse systems are more productive, why sustainable development - involving balanced additions of other circular subsystems – is possible; and most of all, why ecological carrying capacity is by no means a constant, for it depends on how the land is organised for production.

Finally, I proposed that Bradford University would be ideal for an integrated food and energy Dream Farm 2 (see final chapter in our comprehensive report on sustainable agriculture [28] Food Futures Now: *Organic *Sustainable *Fossil Fuel Free , ISIS/TWN publication). It would enable architects, engineers, scientists, designers and artists to work together on the closed loop model; and provide hands-on educational and research opportunities for all levels. The suggestion did not entirely fall upon deaf ears.

Article first published 10/01/11


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  28. Ho WM, Burcher S, Lim LC, et al. Food Futures Now, Organic, Sustainable, Fossil Fuel Free, ISIS/TWN, London/Penang, 2008.

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Rory Short Comment left 17th January 2011 18:06:08
Through evolution Nature gave birth to our species. A unique aspect of our species is our consciousness. As I see it the right use of our consciousness would be to super-charge our ability to work in cooperation with Nature as opposed to ignoring it or working in opposition to it, our practice historically. it seems to me the above article is about examples of using our consciousness in the correct way.