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4 Laws of Ecology


Basis for the Biological Nutrients Cycles of the Circular Economy: Barry Commoner’s laws of ecology

Through his four ‘laws of ecology ‘, Barry Commoner is known as a forerunner of circular economic thinking (De Angelis and Peattie 2022). [1] The textboxes summarize these laws. [2] How De Angelis and Peattie and others link them to the circular economy (CE) is also referenced below.

[1] De Angelis, R., Peattie, K. Return to Reintegration? Towards a Circular-Economy-Inspired Management Paradigm. Circ.Econ.Sust. (2022). https://doi.org/10.1007/s43615-022-00245-y

[2] Basert på Barry Commoner (1974): The Closing Circle  and Barry Commoner (1990): Making Peace with the Planet [ emphasize, bullets and text in brackets added]


The first law of Ecology: Everything is connected to everything else

Commoner expresses the fact that:

the ecosphere is an elaborate network, in which each component part is linked to many others’ (Commoner 1990:8): «Thus, in an aquatic ecosystem a fish is not only a fish (..) It is also

    • the producer of organic waste that nourishes microorganisms and ultimately aquatic plants
    •  the consumer of oxygen produced photosynthetically by the plants
    • the habitat of parasites
    • the fish hawk’s prey

(Commoner 1990:8)

The fact that an ecosystem consists of several interconnected parts that act on each other has some surprising consequences. An astonishing illustration is this 4,5 min-video: How Wolves Change Rivers.

“In the technosphere, “the component parts – the thousands of different man-made objects – have a very different relation to their surroundings. A car, for example, imposes itself on the neighborhood rather than being defined by it (..) It is produced solely as a salable object – a commodity- with little regard for how well it fits into either sphere: the system of transportation or the environment.”

(Commoner 1990:8, emphasise added)

According to De Angelis and Peattie, this underpins the understanding of the biosphere as an ecological network where individual changes, such as loss of habitat or species, could have unpredictable consequences elsewhere:

 “CE thinking, drawing on systems thinking, acknowledges the existence of many parts in a system, i.e., organisations are parts of interconnected economic, ecological, and social systems, and the implications this has for product and system design. A product fit for a CE is one designed considering its interactions with economic and ecological systems along its entire lifecycle, and any organisation wishing to move to a CE needs to consider its wider system interactions.”

De Angelis, R., Peattie, K. Return to Reintegration? Towards a Circular-Economy-Inspired Management Paradigm. Circ.Econ.Sust. (2022). https://doi.org/10.1007/s43615-022-00245-y


The second law of ecology: everything must go somewhere (in nature there is no such thing as ‘waste’)

‘In every natural system, what is excreted by one organism as waste is taken up by another as food’ (Commoner 1974:36). It also expresses [together with the first law] ‘ the fundamental importance of cycles in the ecosphere’ (Commoner 1990:9):

    • “Animals release carbon dioxide as a respiratory waste; this is an essential nutrient for green plants
    • Plants excrete oxygen, which is used by animals
    • Animals organic wastes nourish the bacteria of decay.
    • their wastes, inorganic materials such as nitrate, phosphate, and carbon dioxide, become algal nutrients
    • these, ingested by the fish, contribute to their organic waste, and the cycle is complete.”

(Commoner 1974:36, Commoner 1990:10, emphasise added).

The technosphere, according to Commoner, is dominated by linear processes:

“Crops and the animals to which they are fed are eaten by people, their waste is flushed into the sewer system, altered in composition but not in amount at a treatment plant, and the residue is dumped into rivers or the ocean as waste -which upsets the natural aquatic ecosystem. In the technosphere, the end of the line is always waste, an assult on the cyclical processes that sustain the ecosphere. “

(Commoner 1990: 10,11, emphasise added)

One of the most important premises in Michael Braungart and William McDonough’s book ‘cradle-to-cradle’ is that materials can be designed to separate the biosphere from the technosphere and become nutrients forever:  
    • “Mineral and synthetic materials, which flow in technical cycles, return to continuous cycles of production and consumption since through end-of-life material recovery strategies and appropriate design techniques (e.g., design for disassembly, remanufacturing, product durability), they preserve quality and are suitable for further use. 
    • Renewable and biological materials, which flow in biological cycles, return to nature to build and restore natural capital after cascading them across other applications and extraction of bio-chemical nutrients.” 

EMF and McKinsey (2013): Towards the circular economy: economic and business rationale for an accelerated transition,  quoted in De Angelis and Peattie (ibid.)


In an initiative developed since 2016, William McDonough has added an extra dimension by developing:


A new Language for Carbon that seeks to clarify the terms typically used to describe efforts to reduce carbon emissions and define new, innovative ways in which carbon can be used safely, productively and profitably. In this new paradigm..the life-giving carbon cycle becomes a model for human designs, enabling us to cultivate urban food systems and closed-loop flows of durable materials in which carbon is an asset rather than a liability.

Carbon is not the enemy. Climate change is the result of breakdowns in the carbon cycle caused by us: it is a design failure. Anthropogenic greenhouse gases in the atmosphere make airborne carbon a material in the wrong place, at the wrong dose and wrong duration. It is we who have made carbon a toxin—like lead in our drinking water. In the right place, carbon is a resource and tool.

City infrastructure [in ‘The Net-Positive Carbon City’] adapts to the new idea: for example, sewage treatment plants are reconceived as fertilizer factories and intensive integrated agriculture systems—what we call solar orchards—provide clean energy, clean food, clean water and jobs simultaneously. [‘solar orchards’ are for more than orchards; see here og here].


William McDonough (2022):Net-positive: Waging peace through commerce by design [text in brackets and emphasise added]


McDonough and especially the chemist Braungart have been very keen to avoid toxic and non-degradable materials in the production of goods. Here Commoner’s third law is essential:


The third law of ecology: nature knows best

The ecosystem is characterised by Commoner as ‘consistent with itself, its numerous components are compatible with each other and with the whole’. “Such a harmonious structure is the outcome of a very long period of trial and error – the 5 billion years of biological evolution.” (Commoner 1990:11).

 «Thus the structure of a present living thing or the organization of a current natural ecosystem is likely to be “best” in the sense that it has been so heavily screened for disadvantageous components that any new one is very likely to be worse than the present ones.»

(Commoner 1974:39, emphasise added).

And recirculation is built in; «..for every organic substance produced by a living organism, there exists, somewhere in nature, an enzyme capable of breaking that substance down.» (Commoner 1990:11).

«Certain molecular arrangements are shunned in the chemistry of life.» (Commoner 1990:12). Here Commoner points to the fact that very few chlorinated organic compounds in which chlorine atoms are attached to carbons, occur in living things, and that:

«This suggests that the vast number of chlorinated organic compounds that are possible chemically (many of them are now produced by the petrochemical industry), have been rejected in the long course of evolution as biochemical components. The absence of a particular substance from nature is often a sign that it is incompatible with the chemistry of life.

(Commoner 1990:12, emphasise added).

 «The petrochemical industry has departed from these restrictions, producing thousands of new man-made substances. Since they are based on the same fundamental patterns of carbon chemistry as the natural compounds, the new ones are often readily accepted into the biochemical process. They therefore can play an insidious, destructive role in living things.

For example, synthetic organic compounds may easily fit into the same reactive enzyme niches as natural molecules or may be accepted into the structure of DNA. However, they are sufficiently different from the natural compounds to then disrupt normal biochemistry, leading to mutations, cancer, and in many different ways to death.»

(Commoner 1990:13-14)

Here, Braungart and McDonough have specified the concept of closed circuits/loops:

“In Cradle to Cradle, we confused some readers with the term ‘closed loops’.’  We intended to mean that a material or its component chemicals could be reused endlessly, safely. But the term allowed the misinterpretation that it was okay to design a toxic product in the first place, as long as it could be reconfigured into another toxic product. We never meant that. That leads to monstrous hybrids. We want you to always think, What’s next? [What happens with the product after the end of its first use?]  

[William McDonough and Michael Braugart (2013:212): The Upcycle. Beyond Sustainability-Designing for Abundance, [text in brackets added]

A brief illustration:

«Just to give you an example, to redesign conventional paper towels so that the chemicals used are safe for biological systems, you need to replace 29 or 30 chemicals. That’s just paper towels. Now think of that television set: 4,360 chemicals...»

«..[But] we can now design computers and television sets in which all the parts are defined plastics and metals, glued together with a new reversible glue, so that when the product is heated in a disassembly procedure, the glue shrinks and the parts fall apart, greatly simplifying recovery of all the elements.”


In a more recent article, Perkins 2023 [1] focuses on so-called ‘forever chemicals’:

“All toilet paper from across the globe checked for toxic PFAS “forever chemicals” contained the compounds, and the waste flushed down toilets and sent to sewage treatment plants probably creates a significant source of water pollution, new research has found. Once in the wastewater plant, the chemicals can be packed in sewage sludge that is eventually spread on cropland as fertilizer, or spilt into waterways. 

PFAS are a class of about 14,000 chemicals typically used to make thousands of consumer products resist water, stains and heat. They are called “forever chemicals” because they do not naturally break down, and they are linked to cancer, fetal complications, liver disease, kidney disease, autoimmune disorders and other serious health issues.”

[1] Tom Perkins, 13 Mar 2023, The Guardian: Toxic ‘forever chemicals’ found in toilet paper around the world ] [emhasis added]


Closely related to the above is Commoner’s fourth and final law:


The fourth law of ecology: there is no such thing as a free lunch

«In the ecosphere, this means that any distortion of an ecological cycle, or intrusion of an incompatible component (such as a toxic chemical), inevitably leads to adverse effects.

At first glance, the technosphere appears to be extraordinarly free of mistakes…Yet nearly every modern technology has grave faults, which appear not as failure to accomplish its designed purpose, but as a serious impact on the environment. Cars usually run very well, but produce smog; power plants efficiently generate electricity, but also emit dangerous pollutants; modern chemical farming is very productive but contaminates groundwater with nitrate and wildlife and people with pesticides.»

(Commoner 1990:14)

In ecology, as in economics, the law is intended to warn that every gain is won at some cost. Payment of this price cannot be avoided; it can only be delayed.» (Commoner 1974:42).


It is this last law that De Angelis and Peattie believe has been least taken into account in the circular economy:

«The failure of current production and consumption systems to internalise their external social and environmental costs is a fundamental cause of their unsustainability. The point of this law is that all human interaction with natural systems, particularly exploitation or interference, has consequences. 

This is not arguing that benefts from natural systems are not (fnancially) freely available since many millions of people still rely directly on these systems for nutrition and materials. Even those benefts are not “free” because they depend upon the maintenance of system inputs (water, energy, nutrients) and ongoing system integrity. 

A key implication of the fourth law for CE is that circularity’s ability to contribute to sustainability will be limited while economic systems fail to refect the full socio-environmental costs of resource extraction..»

De Angelis, R., Peattie, K. Return to Reintegration? Towards a Circular-Economy-Inspired Management Paradigm. Circ.Econ.Sust. (2022). https://doi.org/10.1007/s43615-022-00245-y