Karl Marx’s analysis of capitalism provides the key to understanding the environmental catastrophe we’re witnessing, and to gaining a clearer picture of what’s needed to repair our damaged relationship with the Earth.

Marx’s concern with environmental questions grew from his understanding of how humanity is bound to the natural world by a thousand threads. “Man lives from nature”, he wrote in the 1844 Manuscripts, “and he must maintain a continuing dialogue with it if he is not to die. To say that man’s physical and mental life is linked to nature simply means that nature is linked to itself, for man is a part of nature”.

In the same passage, Marx describes nature as humanity’s “inorganic body”. What he means by this, is that when we’re thinking about the things comprised in our existence, we should include, alongside our own bodies, all the objects of nature to which we relate ourselves—those that sustain us in a directly physical, biological sense, and those that nourish us mentally, such as objects of beauty and so on.

If we don’t have access to healthy food, fresh air and water and so on, our physical health will suffer as a result. And the lack of any capacity to enjoy the beauty of nature—through our contact with it in either work or recreation—will affect our mental health.

Every individual must exist in a constant state of interaction with nature to survive, but the particular form this relationship takes can’t be understood in abstraction from the kind of society in which we live. The task for Marx, then, became to explain how and why human society had developed through the course of history, and in particular to understand the destructive dynamics of the capitalist system that was rapidly emerging at the time.

The key to this, for Marx, lay in an analysis of what he called the “social relations of production”—the way in which, in any society, people come together and labour to produce the things we need to survive. To the extent that there is a theory of human nature in Marx, it is this: our essence is to labour collectively to shape the world around us in a way that satisfies our needs.

For most of humanity’s 200-300,000-year history, we have maintained quite a balanced and sustainable relationship to nature. In Australia, for example, Indigenous societies employed sophisticated land management techniques to maintain a healthy and productive landscape for tens of thousands of years before the British invasion of 1788.

And although, wherever human societies have emerged, there has been some impact on the natural environment in which they are situated, it wasn’t really until a few hundred years ago that the scale of the destruction began to become a significant issue. As Marx put it in his notes for Capital, which were later published as the Grundrisse:

“It isn’t the unity of living and active humanity with the natural, inorganic conditions of their metabolic exchange with nature, and hence their appropriation of nature, which requires explanation or is the result of a historic process, but rather the separation between these inorganic conditions of human existence and this active existence, a separation which is completely posited only in the relation of wage labour and capital.”

The term “metabolic rift” was coined by John Bellamy Foster in his book Marx’s Ecology: Materialism and Nature, published in 2000, as a way of bringing together the various elements of Marx’s account of the rupture in relations between human society and the natural world under capitalism.

Although Marx didn’t talk directly about a “metabolic rift”, he frequently used the German word Stoffwechsel, which translates as metabolism (literally “material exchange”). As today, the word in Marx’s time primarily was used in the context of biology and chemistry to describe the circulation and exchange of nutrients, waste and so on in the human body and other living things. But it was also, from the 1850s onwards, increasingly taken up by those, like Marx, trying to understand the functioning of society.

It’s easy to see how the idea of metabolism, or “material exchange”, can be applied in this context. Marx saw human labour as a kind of process of metabolism in which the raw materials of nature are worked up into forms that are useful for human beings. In Capital, Marx described human labour as:

“... first of all, 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. He confronts the materials of nature as a force of nature. He sets in motion the natural forces that belong to his own body, his arms, legs, head and hands, in order to appropriate the materials of nature in a form adapted to his own needs.”

Human labour acts on nature in a way that’s analogous with the action of the human body on the food that we eat. For instance, just like a tree that is transformed into a wooden shack, so, for example, an apple that we eat goes through a series of transformations until it is broken down into nutrients to be absorbed into our cells, along with waste to be excreted and so on.

Marx applied the idea of metabolism not only to the role of labour in shaping the natural world. As well as the metabolic interaction between human society and nature, there is a metabolism within society itself. So in the Grundrisse he writes that the circulation and exchange of commodities within capitalism can also be understood as a kind of metabolism. “Insofar as the process of exchange transfers commodities from hands in which they are non-use-values to hands in which they are use-values, it is a process of social metabolism”, he wrote.

The circulation of the products of labour within a society can be understood by analogy with the circulation of blood within the human body. In a healthy body, the blood transports oxygen, nutrients and so on to where they are needed—keeping the body functioning at full capacity. So too in a healthy society, the exchange of products should function to ensure that everyone is able to live a decent life.

What, then, is the metabolic rift? In the simplest terms, it is a breakdown in the healthy functioning of the metabolic process human society depends on, in both its external aspect—the exchange of material between human society and nature—and its internal aspect—the circulation of material within society.

In pre-class societies, the material exchange that occurs via our labour on the natural world happened in such a way that the two ends of the process—nature and the useful things we produce from it—were related in a more or less direct and transparent way. The raw materials required for the production of basic necessities like food, shelter and so on were mostly sourced from the immediate vicinity of settlements.

In this context, it would be very obvious if the metabolism had broken down in some way—say by an area of land being eroded due to the excessive clearing of trees. And it would be similarly clear if the process of exchange of goods within the community broke down, and the health of one section of the population began to suffer as a result.

With the emergence of class society, when a minority of the population came to live off the surplus produced by others, the link between the natural basis of human society and the lives of those who made the important decisions became more tenuous.

As Marx sees it, however, it’s only with the emergence of capitalism from the seventeenth century onwards that the link is severed completely. Even the wealthiest of feudal lords still had some connection to the land. Their power was bound with a particular estate. As Marx himself put it in a note, “[T]here still exists [under feudalism] the semblance of a more intimate connection between the proprietor and the land than that of mere material wealth. The estate is individualised with its lord: it has his rank, is baronial or ducal with him, has his privileges, his jurisdiction, his political position etc. It appears as the inorganic body of its lord”.

If the feudal lord failed to manage the land sustainably, if he logged all the forests, poisoned the waterways and so on, he would undermine not only the source of his material wealth, but his identity and being as a lord.

The alienation of the land—its reduction to the status of property that can be bought and sold—is what for Marx constitutes the foundation stone of the capitalist system. The wealth and power of the capitalist class doesn’t depend on their possession of this or that particular piece of property, but rather on their control over capital. Capital can include physical property, such as farmland, machinery, factories, offices and so on, but it is by its very nature fluid and transferable. If a capitalist buys up some land and then destroys it, they can simply take the profits they’ve made from it and move their money elsewhere.

At the same time as it completely severs any semblance of connection with the land among the ruling class, capitalism also severs it among workers. The peasants under feudalism had a direct and transparent dependence on the land for their subsistence. But with this came a degree of independence that isn’t afforded to workers under capitalism. The peasants had to give up a portion of their produce to the lord, but outside of that they were relatively free to labour as it best suited them. And no matter how unfree they were in a political sense, their capacity to sustain themselves was at least guaranteed by their direct access to the land and their possession of the tools necessary to work it.

For capitalism to be put on firm footing, this direct relationship of the peasants to the land had to be severed. They were, over a number of centuries, forcibly “freed” from the land in order that they could be “free” to be employed in the rapidly expanding capitalist industries. Workers, for Marx, are defined by their lack of ownership of the means of production. They are no longer dependent on the land for their subsistence, but rather on the preparedness of a capitalist to give them a job and pay them a wage.

Even if they might still maintain a more or less direct relationship with nature in their work, they have no control over or stake in this at all. Their dependence is on the wage they receive, rather than on, for example, the continuing productivity of the land on which they work.

Many workers under capitalism are, of course, concerned with the destruction of the environment. But unlike with the peasantry under feudalism, whose need to maintain a sustainable relationship with the natural world is clear and immediate, the question of environmental protection under capitalism doesn’t appear, on the surface, to relate to our immediate material needs at all.

This combination of factors—the capitalist class not having any real incentive to protect the environment, and the working class having no control over it—lies at the heart of capitalism’s unique destructiveness. The “logic” of capitalism is one in which maintaining the health of society’s metabolism—either externally in its relationship with nature, or internally in its distribution of goods among the population—only features to the extent that it assists the accumulation of wealth by the ruling class.

The one thing the capitalist class cares about above all else is profit. No matter what the consequences, whether on the natural environment, human health or anything else, if business owners can continue to expand their pool of capital, they will see it as a success. And, due to their lack of means of production, and their dependence on selling their labouring capacities to a capitalist in exchange for a wage, workers have been harnessed to the same destructive wagon.

To understand the idea of the metabolic rift better, it will help to provide some examples. For Marx and Engels, writing when capitalism was still only in its infancy, the increasing split between the country and the rapidly growing cities illustrated the point most clearly. In volume 3 of Capital Marx explained that capitalism:

“reduces the agricultural population to an ever-decreasing minimum and confronts it with an ever-growing industrial population crammed together in large towns; in this way it produces conditions that provoke an irreparable rift in the interdependent process of social metabolism, a metabolism prescribed by the natural laws of life itself. The result of this is the squandering of the vitality of the soil, which is carried by trade far beyond the bounds of a single country”.

Prior to the emergence of capitalism, the productive life of society was more dispersed through a patchwork of villages and towns. There was no clear divide between the city and the country as there is today. One of the consequences of this was that the nutrients that went into agricultural production could easily be recycled back into the soil from human, animal and plant waste.

Once capitalism’s drive to profit kicked in, however, the imperative was to centralise production to increase efficiency and reduce the costs of labour and so on. Industry became more and more concentrated in urban centres. The waste from this human mass, instead of being returned to the soil, was simply dumped into rivers or the sea. As well as making cities like London unbearably smelly and disease ridden, this dynamic also led to declining soil fertility, which worsened as the nineteenth century progressed.

Farmers became desperate to find alternative sources of nutrients to regenerate the soil. The first to go were the bones from historic battlefields like Waterloo. Then, following the discovery that guano—more commonly known as bird shit—contained high levels of nitrogen and phosphorus crucial for crop growth, there was a global scramble to secure supplies of this precious resource. In 1856, the US passed the Guano Island Act by which it annexed and occupied more than 100 islands known to be rich in guano.

So the disruption of one aspect of the metabolism between human society and nature led immediately to disruption in other areas. With the focus on short-term profits, the idea that you would build a system to recycle waste from the cities back into the agricultural areas didn’t even enter the frame. Why would you invest in a scheme like that when you could make money from importing guano from distant Pacific islands? Marx summed up the situation, again in the third volume of Capital, arguing that “the moral of history ... is that rational agriculture is incompatible with the capitalist system”.

Looking at the situation today, it’s hard to argue with this. Massive amounts of labour and resources are spent artificially maintaining the nutrient levels of soils, and more and more forests and other crucial ecosystems are swallowed up in the constant drive to expand agricultural production. Meanwhile most of the nutrient-rich waste produced in our cities continues to be thrown away.

Perhaps the best example of the metabolic rift is climate change. The centrality of fossil fuels to capitalism is, for a start, related to the drive to liberate capital accumulation entirely from any natural constraints. Fossil fuels had the advantage, over other nineteenth century sources of energy, of being easily transportable, and being able to be switched and used at will. This meant production could take place 24 hours a day, independently of climatic conditions or any other external factor, and could be geographically located wherever it was most advantageous to the factory owners.

This is one of the main developments that drove the rapid expansion of cities. Instead of having to set up in regional areas, where local traditions of working-class solidarity could be hard to break, industry could be clustered together in one place, forcing masses of workers to relocate and creating huge pools of unorganised labour that could be exploited at will.

Even putting aside the question of global warming, which of course didn’t figure in Marx’s time, fossil fuels might, in a society with a healthy external and internal metabolism, have been rejected because of their many other damaging aspects. But with the emergence of capitalism, the only goal that came to matter was the accumulation of wealth in the hands of the bosses. And there has perhaps never been a commodity so profitable for the capitalist class as fossil fuels.

Today, the metabolic rift that underlies the climate crisis is even clearer. Scientists have known about the damaging consequences of the burning of fossil fuels for 50 years. And we have long had the technology to begin a transition to alternative sources of power such as wind and solar. Despite this, and despite the increasingly urgent warnings of scientists over the last decades, global emissions are higher than ever, and millions around the world are already suffering from an increasing frequency of extreme weather, droughts, bushfires and so on.

What explains the failure to act? A big part of it is that those with their hands on the levers of power are the people who are reaping all the benefits from the continued use of fossil fuels, while those who are feeling the most effects of climate change have the least power to do anything about it.

Never has there existed a class of people so cut off from nature as the capitalists and their political servants. Why would we expect them to care much about the damage they are causing when their immense wealth can act as a shield against many of the consequences of their actions?

There is perhaps no better expression of the physical and spiritual chasm that has opened up between today’s capitalists and the natural world on which their wealth ultimately depends, than the fad—personified in Elon Musk—for the colonisation of space. It’s telling that the idea of building a new civilisation on Mars is so popular with these people. They have so little sense of their connection to or care for the natural world that the idea of an interplanetary escape seems more realistic and attractive than any real effort to fix the problems we have on Earth.

How did Marx foresee the healing of the rift between human society and nature? That this rift is grounded in the fundamental economic structure of society means, obviously, that a bit of tinkering here and there won’t be enough. Marx was unambiguous on this point: to heal our relationship with the Earth, we need revolution. At the heart of this revolution will be the destruction of the system of private property, in which the natural environment is reduced to the status of a commodity to be bought and sold. The healing of the metabolic rift begins with the return of the land, and the means of production required to work on it, into the hands of the working class.

Marx’s vision of socialism was of a society centred on the collective, democratic control by workers of the process of production, and of the distribution of goods. Translating this into the language of metabolism, we might say: the conscious, democratic control over society’s internal and external metabolism, a control which would enable us quickly to identify problems and to adjust our practice accordingly.

In a socialist society, for example, the barriers to a global shift away from fossil fuels would disappear. There would be no entrenched economic interests fighting tooth and nail to protect their profits. We could have a genuine discussion and debate about the best way forward, informed by the latest science, instead of the mess of misinformation and corporate propaganda that we’re bombarded with today. And we would be able to mobilise immense new resources that in capitalism are tied to useless or destructive industries such as the military, advertising, policing, high-end housing and so on.

Instead of everything being geared towards the generation of ever greater profits, we would be thinking about what’s good for society. And for Marx, a healthy metabolism—which ensures both a sustainable exchange of material between human society and nature, and the circulation of goods to provide everyone with a decent life—was the key to a healthy society. Marx summed up his view of the relationship between human society and nature as follows:

“From the standpoint of a higher economic form of society, private ownership of the globe by single individuals will appear quite as absurd as private ownership of one man by another. Even an entire society, a nation or all simultaneously existing societies taken together are not owners of the Earth, they are simply its possessors, its beneficiaries, and have to bequeath it in an improved state to succeeding generations, as good heads of households.”

In Marx’s time, the rift between human society and nature was still in its early stages. Today, it has deepened and widened to the point where it threatens global catastrophe. But there is nothing inevitable about the slide towards environmental collapse. Most people gain nothing from the capitalist status quo. Together, we can bring down this rotten system and build a socialist society in its place.