For the last twenty years the idea of the “metabolic rift” has become a key component in reconstructing an approach to environmental crises based on the works of Marx. This has been critically discussed in the pages of Solidarity, particularly by Paul Hampton who has suggested that these ideas are an important source for anyone seeking to understand how capitalism impacts on the environment but do not constitute a rounded theory.Here, I take a more critical approach and suggest that the idea of the metabolic rift may be a dead-end.
The idea of the metabolic rift has been popularised by John Bellamy Foster who has (with others) done important work in showing that Marx and the pre-Stalinist Marxist tradition was strongly engaged in environmental issues. However, it is the detail of his understanding of “metabolism” that I wish to question. He suggests that in the 1840s Marx took Feuerbach’s idea that people are part of nature but have become separated (alienated) from it through (in Marx’s rendering) class society and especially capitalism. The rift is that separation. Thus one of the tasks of a socialist movement is to restore humanity to its intermit relationship with nature. Foster, and more assertively Kohei Saito in Marx's Ecosococialism, argues that this idea was developed in Marx’s later works, particularly Capital. Both Foster and Saito see this as an unfinished project, although Saito makes the extravagant claim that it is “not possible to comprehend the full scope of [Marx’s] critique of political economy if one ignores its ecological dimension.”
Metabolism and Marx
First, attention should be given to Marx’s use of the word “metabolism” (or rather the German word Stoffwechsel). Stoffwechsel also has a more elemental meaning of “interchange of materials” which informed early English translations of Capital. Only in the 1970s did new Penguin translations render this as “metabolism”. This had the merit of making this element of Marx’s thought more transparent, but this needs careful contextualising.
Marx used the word Stoffwechsel in two senses in Capital (neither in an extensive or elaborated way).
1. The “social metabolism” of commodity circulation
Marx’s use in Capital of “social metabolism” might be considered an analogy although the circulation of commodities as material things can be seen as a step on from humanity’s metabolic relation with nature. Either way, this usage sheds light on Marx’s thinking.
The term is used to describe the circulation of commodities in an unchanged form (a coat retains its form as a coat even as it is bought and sold). This movement is pushed (mediated) by a different process, exchange with money. Here there is a change of form, the value in the form of the coat becomes value in the form of money: Marx calls this “the change in form or the metamorphosis [Metamorphose] of commodities”).Marx also uses the German words Formveränderung and Formwechsel [change of form] as a synonym for this metamorphosis.
So when Marx uses Stoffwechsel/metabolism he means a process of movement of a material thing that does not change its form. This has nothing to do with the biological process of metabolism which involves changes in form, e.g. from chemical energy to energy in heat. In this context the older translation in Capital (“interchange of material”) has some virtue as a translation of Stoffwechsel.
2. The “metabolic” relationship between humanity and nature.
The second sense is the more important here. “Labour is”, writes Marx in Capital, “a process between man and nature, a process by which man, through his own actions, mediates, regulates and controls the metabolism between himself and nature.”“Metabolism” here does not refer to the transformative labour but the movement (appropriation) of material. This movement cannot happen without transformative labour, but it is this labour that facilitates (mediates) this movement of Stoff.
It is important to note the word “between” (zwischen). This has nothing to do with a modern understanding of biological metabolism, a process within a cell or organism which has no “between”. Again, it appears Marx was not thinking of metabolism in the biological sense at all, but the “exchange of material”. Labour is pulling Stoff (material) out of nature, and in so doing it is transformed into the product of labour. But insofar as the material also remains the same material, it is this to which Stoffwechsel/metabolism refers.
The “metabolic rift” and soil science.
Finally in volume 1 of Capital Marx arrives at the “rift”:
“Capitalist production collects the population together in great centres, and causes the urban population to achieve an ever-growing preponderance … it disturbs the metabolic interaction between man and the earth, i.e. it prevents the return to the soil of its constituent elements consumed by man in the form of food and clothing; hence it hinders the operation of the eternal natural condition for the lasting fertility of the soil.”
This is a very specific point about agriculture and returning human waste (rags, faeces, bones) to the soil. This was no great new insight, rather Marx followed the changing position of the biochemist Justus von Liebig who in the 1840s favoured fertiliser to boost agricultural production, and by the 1860s had changed his position to one where (in Marx’s terms) capitalist agriculture was robbing the soil for profit.
This is another iteration of Stoffwechsel as the movement of material. Here the movement is of soil nutrients that are passed to plants and thence to humanity in the form of clothes and food, all the time unchanged it would appear, and what is necessary is to pass the spent residues back to the soil to complete an “eternal” cycle with the earth. This is the description of a cycle without transformation/metamorphosis. It is much more of the form of “material interchange” than of metabolism in its biochemical sense.
But more. If we look closer at the assumed “nature”, both agricultural land and the crops that grow on it are already the products of previous human labour. Most farmland was originally forest, cleared not under capitalism but in the previous 10,000 years of settlement, at least in Europe and the near East. The repeating tilling of the land, the use of natural and manufactured fertilisers, the sowing and harvesting of crops or the grazing of livestock (whose characteristics are themselves the product of human intervention) make this land the product of human labour. Marx and Engels recognised this point as early as 1845 in The German Ideology: pristine “nature … no longer exists anywhere (except perhaps on a few Australian coral islands of recent origin)”. Marx recognises this to a degree in Capital, “Animals and plants which we are accustomed to consider as products of nature, may be, in their present form, not only products of … last year's labour, but the result of gradual transformation continued through many generations under human control, and through the agency of human labour.”
Marx may have underestimated the degree to which agricultural land is the product of human labour. For example, in many parts of Northern Europe from the late Bronze Age, rich plaggen soils were formed by digging animals’ winter bedding into arable land each spring, this building up a fertile soil over hundreds of years.
The point here is that the “metabolic rift” does not account for a “nature” that is already the product of past human activity. Most relevantly to the work of Foster and Saito, it shows that Marx did not have the worked through ecological perspective they suggest, let alone the greater theory covering “depletion of coal reserves, the destruction of forests, and so on” that Foster suggests although Marx did recognise these as problems.
In much of this Marx drew from Liebig, an important forerunner of soil science who discovered the importance of nitrogen, phosphorous and potassium in plant nutrition. As a chemist, however, he had limited practical understanding of soil which led his underestimation of both its physical and biological nature.
Saito points to Marx’s interest in the German botanist and agronomist Carl Fraas around 1868 (although on a slim amount of material in the new Marx-Engels collected works MEGA2). Against the chemist Liebig, Fraas was interested in soil’s physical qualities and its interaction with the climate (Saito makes far too much of Fraas’s theories of climate change which has no relationship to our current greenhouse gas driven crisis).
The problem was that Marx was ploughing the wrong furrow by studying Fraas. After Liebig, the next step towards modern soil science was made by the German geologist Friedrich Fallou, with works published around 1860 which established the study of soil in its own right including the examination of its formation and degradation. This was developed by Vasily Dokuchaev, publishing only the year of Marx’s death. His view was of soil as a changing system with chemical, physical and organic elements as the basis for understanding soil.
Town and country
The one programmatic proposal to follow from Marx’s view on the “metabolic rift” was that the distinction between town and country should be abolished. Marx held this view long before developing ideas of soil depletion, it being mentioned in the Communist Manifesto (1948)
The closest to an elaboration of this comes in Engels’s Anti-Dühring. As Engels documents, early utopian socialists favoured rural communes combining farming with manufacture. The reasons for support of this are stated in numerous places in Marx and Engels’s work: industrial towns were crowded, fetid, dirty and polluted, stunting the workers’ bodies, whereas the countryside offered a healthier physical environment that was intellectually stultifying.
This was problematic even in the 1870s. About a fifth worked in agriculture at that time, and the figure now even for a net food exporter like the US is less than one in fifty. There would be little agricultural work for most of these commune dwellers. Engels envisaged each commune having a population of 1,600 to 3,000. Even increasing this to 10,000, in England it would now need communes at intervals of every two miles(east to west and north to south) across the country to house everyone (and 2 million miles of road to link them, ten times the current amount, not to mention other infrastructure). Even when Engels was writing the population of England would have required a commune every four miles. This is the obliteration of the countryside.
Perhaps there are cities in the developing world (most notably in India) as polluted as Victorian Britain’s worst, but the best of developed world cities show the potential for these being healthier places with better housing, sewerage systems, clear air laws and (more recently) limitations on traffic.
In the 1960s Jane Jacobs advocated for densely populated cities as places where people walked more, shared local amenities and were (literally) places of conviviality. Suburban and rural living on the other hand relies on cars to access dispersed and often poor quality services. These ideas have been developed in the context of the climate crisis by a range of writers who point to Manhattan being the low carbon place to live in the US – it has both the lowest car ownership and per capita energy usage in the US, and high rates of walking.
Figures from the US for personal direct per capita CO2 emissions (2016) show Washington DC producing 2.6 tons per head simply by being largely urban (even though it is not a pedestrian friendly city: everyone drives and the city sprawls).The more rural Wyoming produces 14.8 tons. Alaska is higher still at 18 tons, but this suggests that people should not live in frozen wilderness.
Nor does the “metabolic break” reasoning for rural living still pertain. Such a rift no longer exists in the UK where around 80 per cent of human waste in the sewerage system is returned to the land in the form of fertiliser. Even so, only around 1% of the fertiliser used in the UK comes from sewerage.
There is thus no environmental case for semi-rural life, but rather a case for high density cities. As far as human faeces is a useful fertiliser (and it certainly does not have the important role that Marx supposed for it), urban living facilitates its collection and use.
There is more that could be said about how humanity might wish to distance itself more from nature, to widen the rift. The current pandemic shows the need to put a rift between ourselves and natural pathogens. The history of the earth has instances of natural shifts in its environment which we may need to counter.
Generally, there can be no restoration of some supposed “unity” between humanity and nature. The earth is already the product of humanities long term activities. There are no giant land sloths in the Americas not because of capitalism, but because hunter-gathers with rocks ate them all. The surface of the earth is not what nature made, it is what millennia of agriculture has made.
This is not an excuse for being blasé in the face of environmental crises, but we live in an environment that our activity has shaped. Only by understanding how we have shaped our environment process can be hope to maintain a habitable. This is not to promote technological fixes – much of what is immediately needed is to stop doing harm (not pump CO2 into the atmosphere, not deforest, not dump plastics into the sea, not farm in a way that will destroy soil, not overuse fertiliser and pesticides, not fatten animals in feedlots and presume not to take what we cannot replenish in a circular economy). The necessity is, as Marx and Engels pointed out, for humanity to manage their environment collectively and rationality.
 A selection of these articles can be readily accessed via . A general search on the site for Paul Hampton
or Paul Vernadsky will yield further articles.
 The evidence that I present is in a number of fields where I claim no special expertise and all could bear further investigation. My comments here are much more to open a debate than an attempt to finish one. In doing this, I will seek to understand Marx’s ideas both in the context of their own time and it the light of more recent environmental science.
 The ideas of metabolism remained a feature of Marxist debate at least until the 1920s, when it fell out of favour with the Stalinist ideologues of the Soviet Union. Its final demise was probably Stalin’s execution of Bukharin in 1938. It did not help that the main non-Stalinist school of Marxist thought, the Frankfurt school, were uninterested in the concept. As far as I am aware, although the concept was occasionally mentioned after the work “metabolism” was used in the new Penguin translations of Capital published from 1976, the first systematic and extended re-introduction of these ideas is in John Bellamy Foster (1999), “Marx's Theory of Metabolic Rift: Classical Foundations for Environmental Sociology” in American Journal of Sociology, 105(2), 366–405; and then more completely in Foster (2000) Marx's Ecology: Materialism and Nature (Charlesbourg, Québec: Monthly Review Press).
 Kohei Saito (2017) Marx's Ecosocialism: Capitalism, Nature, and the Unfinished Critique of Political Economy (New York: Monthly Review Press) p14. Emphasis in original.
 There is a cluster of six uses of this in Karl Marx (1976) Capital: A Critique of Political Economy Volume 1(Harmondsworth: Penguin). pp198, 199, 206, 210, 217, 228. All references to Capital in English are to the Penguin editions.
 Marx (1976), p198-199.
 Saito (2017), pp75-76 (with a slight return at p91) recognises the use of Formwechsel alongside Stoffwechsel but strangely he does not consider its relationship with Marx much more common use of the word metamorphosis. Even more strangely, after this short discussion, Saito does not return to the Form-Stoff distinction (or the dual nature of commodities in general) or include this in his ongoing analysis. Instead, he buries the point in the much longer and very general discussion of metabolism that fills the rest of the chapter.
8 This can be found in the German edition, Karl Marx (1962) Marx-Engels-Werke (MEW) - Band 23 (Das Kapital - Erster Band) (Berlin: Dietz Verlag), p149. The corresponding page in the English edition: Marx (1976), p223.
Elsewhere in volume one of Capital Marx makes exactly the same distinction, stating, “As far as concerns its material content, the movement is C-C, the exchange of one commodity for another, the metabolic interaction of social labour, in whose result the process itself becomes extinguished.” That is, if two commodities as use values are exchanged for consumption, the social process is over as they are consumed. But Marx continues, “C-M. First metamorphosis of the commodity, or sale. The leap taken by value from the body of the commodity into the body of the gold is the commodity's salto mortale [dangerous jump]”. (Ibid., p200). So metabolism is the process through circulation of a commodity, say a pair of shoes, which continues being exchanged until ending in on the feet of its consumer, at which point it is “extinguished” from the point of view of this process. This is facilitated by a process of metamorphoses where the commodity is transformed into money in the act of buying and selling. The same usage can be seen again at ibid. p210.
This is repeated for the circulation of money which as far as it continues in its form as money it is described as being involved in a “metabolic process”. When that money is exchanged for commodities it is involved in “diametrically opposed metamorphoses”. Marx continues, “So the velocity of circulation of money is merely a reflection of the rapidity with which commodities change their forms, the continuous interlocking of the series of metamorphoses, the hurried nature of society's metabolic process, the quick disappearance of commodities from the sphere of circulation, and their equally quick replacement by fresh commodities” Ibid., p217. And again, “Commodities are … sold not in order to buy commodities, but in order to replace their commodity-form by their money-form. Instead of being merely a way of mediating the metabolic process [Stoffwechsel], this change of form becomes an end in itself.” Ibid., p227-228.
 Marx (1976), p283.
 In the German edition: Marx(1962), for example, on p198.
 There are, of course, plenty of ecological writers who extend the idea of metabolism to a system level and others who see separate biological entities forming a symbiotic whole. If this is more than an analogy, I would argue that it is problematic in most cases.
 This perhaps harks back to the earliest experiments on what would later be called metabolism or Stoffwechsel. Santorio Sanctorius (1561-1636) was one of the first in European science to grasp the idea that there were processes of change inside the body. In exploring this he carefully weighed the food he ate, and the piss, sweat and faeces he excreted. But this input-output (exactly what Marx seems to be using metabolism to mean) was not his study, but the means by which Santorius could establish whether something else unseen was going on inside his body. He did find that there was an unexplained drop in his weight which he could not properly explain.
 Marx continues in volume 1 that the labour process is: “an appropriation of what exists in nature for the requirements of man. It is the universal condition for the metabolic interaction [Stoffwechsel] between man and nature, the everlasting nature-imposed condition of human existence, and it is therefore independent of every form of that existence, or rather it is common to all forms of society in which human beings live.” (Marx (1976), p290). Again interesting stuff, but here our interest is that this is metabolism between humanity and nature, it is taking material. The transformation of this material is not part of the metabolic process. Perhaps Marx is seeing this, as with commodities, as having a dual nature. It is interesting that the translator has chosen “metabolic interaction” here rather than metabolism, tending to blur the two German meanings: it the original German it is the “allgemeine Bedingung des Stoffwechsels zwischen Mensch und Nature” (“general condition of the Stoffwechsel between man and nature”) [Cross reference with the German edition Marx (1962), p198]
 Marx never uses the term, although the two words do appear in the same sentence. The term was, as far as I know, coined by Foster. But it is reasonable to suggest that Marx did apply this concept on a few occasions other than the soil nutrient case, including discussing the sustainability of coal and mineral mining.
 Marx (1976), p637.
 There is more material in volume 3 of Capital and the drafts, but it adds no greater clarity to the above picture.
 Jed Kaplan, Kristen Krumhardt and Niklaus Zimmermann (2009) “The prehistoric and preindustrial deforestation of Europe” in Quaternary Science Review Volume 28, Issues 27–28, December 2009, pp3016-3034.
18 Karl Marx and Friedrich Engels (1975) Marx-Engels Collected Works,Vol
5 - 1845-1847 (New York: International Publishers), p40.
 Marx (1976), pp285-286.
 Hans-Peter Blume and Peter Leinweber (2004) “Plaggen Soils: landscape history, properties, and classification” in Journal of Plant Nutrition and Soil Science, 167(3), 319–327.
 Foster (1999), p385.
 William H Brock (1997) Justus von Liebig : the chemical gatekeeper (Cambridge: CUP), chapter 6.
 Saito (2017),pp228-255.
 Salvatore Engel-Di Mauro, (2014) Ecology, Soils, and the Left: An Eco-Social Approach (New York: Palgrave Macmillan), pp140-141.
 Albeit on a shopping list of demands, and at number nine. These probably represented the opinion of the Communist League but there is no evidence that Marx and Engels did not hold these opinions too.
 Friedrich Engels (1987) Collected Works, Vol. 25: Engels: Anti-Dühring, Dialectics of Nature (New York: International Publishers), p278.
 Brian Beach and W. Walker Hanlon (2018) “Coal Smoke and Mortality in an Early Industrial Economy” in The Economic Journal Volume128, Issue615, November 2018
 Jane Jacobs (1961), The Death and Life of Great American Cities (New York: Vintage Books)
 See, for example, Edward Glaeser (2014) Triumph of the City: How Our Greatest Invention Makes Us Richer, Smarter, Greener, Healthier, and Happier (New York: Penguin) pp206ff (section “Dirty Footprints: Comparing Carbon Emissions”). This book has a strong pro (regulated) market approach but contains some sound data and a reasonable, if somewhat skewed, defence of high density urban living form a cultural, economic and environmental viewpoint. Also see Owen, David (2009) Green Metropolis: Why Living Smaller, Living Closer, and Driving Less Are Keys to Sustainability (New York: Riverhead Books).
 See Owen (2009), chapter 1.
 U.S. Energy Information Agency. Energy-Related Carbon Dioxide Emissions by State, 2005-2016
February, 2019. (). The figures here are adapted from tables 4 and 6. [Glaeser gives some very different figures, that a Washington DC household produces around 43 tons per year, but I have checked this back to source and it is a typo, it should be 4.3. This is also not a great figure since its low level reflects that Washington has little industry, agriculture and associated transport costs and I have used a more focused measure.]. There is some debate around the degree to which these headline figures give an accurate picture, for example see Peng Du and Anthony Wood (2018) Downtown High-Rise vs. Suburban Low-Rise Living: A pilot study on urban sustainability (Chicago: Council on Tall Buildings and Urban Habitat). But there seems little doubt that urban living allows for effective public transport, more walking and cycling, fewer cars, communal facilities (be that on a market or collective basis), more energy efficient buildings and so on.
33 OFWAT (2015) "Water 2020: Regulatory framework for wholesale markets and the 2019 price review: Appendix 1" (), p5. That 80% of the food consumed in Britain is imported is another matter, and one that Marx did comment on (following Carey who made the same point very much in line with his protectionist economic policy). Thus around 400% of the faeces resulting from people eating food grown in Britain is returned to the land, with a deficit to countries that are net exporters of food.