# Howard T. Odum's contribution to Marxian ecological thought

Raffaele Guarino, Enrique Muñoz-Ulecia

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Raffaele Guarino, Enrique Muñoz-Ulecia. Howard T. Odum's contribution to Marxian ecological thought. Ecological Modelling, 2026, 511, 7p. 10.1016/j.ecolmodel.2025.111376. hal-05365574

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# Howard T. Odum's contribution to Marxian ecological thought

Raffaele Guarino<sup>a, *, ID</sup>, Enrique Muñoz-Ulecia<sup>b, c ID</sup>

## ARTICLE INFO

**Keywords:**

Social metabolism

Energy theory of value

Labour

Metabolic rift

Ecological economics

## ABSTRACT

This article explores Howard T. Odum's contributions to Marxian ecological thought through an analysis of his energy systems theory, its intersections with Marxian critiques of capitalism, and its relevance for contemporary debates on global ecological crisis and inequalities. We first describe how Odum's system ecology and environmental accounting can provide complementary insights to inform a biophysical critique of capitalism, by revealing the hidden energy flows that underpin economic processes. In particular, Odum's concept of emergency and his critique of conventional economics anticipated central debates within ecological economics, notably the need to ground economic analysis in thermodynamic realities and to account for nature's essential, yet often disregarded, contributions to human well-being. Then, we explore the similarities between Odum's emergency valuation of real wealth and Marx labour theory of value. Lastly, we connect Odum's analysis to Marxian ecological theories, particularly the metabolic rift thesis, illustrating how Odum's quantification of energy hierarchies complements Marx's historical-materialist critique of capital's exploitation of socio-economic systems. We argue that integrating Odum's biophysical perspective with Marx's critique of capitalism's exploitative logic provides critical insights into capitalism's systemic reliance on thermodynamic inefficiency and global resource extraction. This convergence between systems ecology and historical materialism can offer valuable tools to rethink sustainability within social and biophysical planetary boundaries.

## 1. Introduction

"Now in the new millennium, changes in the economy and its relationship to environmental resources, growth, and social welfare raise questions about which measures of value are appropriate for public policy." This opening assertion in the work, "An Energy Systems View of Karl Marx's Concepts of Production and Labour Value", (Odum and Scienceman, 2005) underscores the engagement of Howard T. Odum with the broader debate on value, labour and energy within Marxist tradition, highlighting the urgency of redefining these categories in an era of ecological crisis and economic inequality. According to Foster and Holleman (2014), from the 1980s onward, H.T. Odum, alongside Scienceman, critically examined Marx's labour theory of value through an energetic lens. Although from a different scientific tradition, Odum's engagement ran in parallel with key Marxist thinkers such as Arghiri Emmanuel (1972) and Samir Amin (1974; Amin, 1978), whose work laid

the foundations for the theory of ecologically unequal exchange. By quantifying energy flows and transformations, Odum provided a rigorous analysis of the biophysical foundations for the establishment and maintenance of social-ecological systems. In doing so, he exposed the asymmetries embedded in industrial economies between economic value and the "real wealth" as well as the unequal global resource distribution between rural and urban systems (Odum, 1971), also known as core-periphery<fnref n="1" /> dynamics (Corsi et al., 2024). While the contribution of Odum in system thinking and ecology is widely recognized (Patten, 1993; Brown and Ulgiati, 2004) his contribution to Marxian thought has been often marginalized (Foster and Holleman, 2014).

This paper contributes by tracing Odum's engagement with Marxian theory and investigating the potential of a "Marx-Odum dialect" as articulated by Foster and Holleman (2014) to this paper advances an ecological critique of the contemporary socio-ecological crisis. Firstly, it examines Odum's ecological thought, particularly his conceptualization

<footnote><sup>a</sup> International PhD Programme / UNESCO Chair "Environment, Resources and Sustainable Development", Department of Science and Technology, Parthenope University of Naples, Italy</footnote>

<footnote><sup>b</sup> Université de Toulouse, INRAE, INPT, El PURPAN, AGIR, Castanet-Tolosan, France</footnote>

<footnote><sup>c</sup> Departamento de Ciencia Animal, Centro de Investigación y Tecnología Agroalimentaria de Aragón (CITA), Av. Montañana 930, Zaragoza 50059, Spain</footnote>

<footnote>* Corresponding author.</footnote>

<footnote>E-mail address: raffaele.guarino003@studenti.uniparthenope.it (R. Guarino).</footnote>

<footnote n="1">¹ As conceptualized in Wallerstein (1974), Core refers to developed economic centers (overlapping with Global North) and Periphery refers to underdeveloped regions at the margins of world's economic organization (overlapping with Global South).</footnote>
of emergence as a measure of the energy required to sustain both Earth's systems and human society. Second, we describe Odum's theory of wealth and his critique of monetary valuation, engaging with how scholars diverge in their interpretation of Odum's valuation being or not an energy theory of value and exploring the similarities with Marx's labour theory of value. Third, it explores how Odum's framework has been interpreted within eco-Marxist debates, particularly in dialogue with Foster and Holleman (2014) and Hornborg (1998; 2014, 2015). We argue that synthesizing Odum's systems ecology with Marx's historical materialism can help build a biophysically grounded critique of capitalism's exploitative logic while retaining a strong consideration of social relations and power dynamics.

## 2. Howard T. Odum's ecological thought

### 2.1. The energy basis for nature and society

Odum was among the first ecologists to apply systems theory to environmental and economic processes. He conceptualized ecosystems as dynamic networks of energy and material flows, where primary producers like plants transform solar energy into biomass sustaining all higher trophic levels (Odum, 1988). This framework reveals a profound truth: every material form we observe represents the “record” of past energy used up, with its transformation history constituting nothing less than the natural history of life itself (Odum, 1996; 1971). Odum devoted himself to understanding how energy works and how it drives, through possibilities and constraints, the maintenance and development of life. He began investigating how many forms of energy exist, seeking for the original source of all energy forms which he first thought to be solar energy.<fnref n="2" /> Here, through nuclear fusion, the sun converts hydrogen into helium, transforming a minute fraction of mass into electromagnetic energy. This energy originates as high-energy gamma photons that gradually degrade through interactions with solar plasma, emerging as ultraviolet, visible and infrared radiation. Remarkably, only about one two-billionth of the sun's total energy output reaches Earth, yet this tiny fraction sustains nearly all planetary life, serving as the energetic foundation of Earth's socio-ecological systems (Odum and Odum, 1976). Of the solar energy reaching Earth's surface, only a portion falls within the range known as Photosynthetically Active Radiation (PAR), corresponding to wavelengths between approximately 400 and 700 nanometers, which can be directly harnessed by plants for primary production (Odum and Odum, 1976). This continuous solar influx enables the conversion of soil nutrients into chemical energy stored in biomass, allowing the multiplication of the forms of energy through the trophic chain.

However, Odum recognized that the role of solar energy extends far beyond photosynthesis, pointing out that solar energy also contributes to the Earth system in the form of thermal energy, driving atmospheric circulation, climate regulation, and other key ecological processes. Ultimately, all forms of energy can ultimately be converted into heat, which is commonly measured in calories. Heat, representing energy in its most dispersed and low-quality form, results from molecular motion and obeys the second law of thermodynamics by flowing inexorably from warmer to cooler regions (Odum and Barrett, 2005). These thermal dynamics have cascading ecological effects. Temperature gradients drive atmospheric circulation, shaping wind patterns and precipitation cycles that distribute energy on a planetary scale. In marine systems, combined thermal and salinity variations generate ocean currents that regulate upwelling and downwelling processes essential for nutrient cycling (Odum, 1996). Odum also extended his analysis of energy transformations to geological processes, demonstrating how Earth's

internal heat, a combination of residual energy from planetary formation and ongoing radioactive decay, fuels tectonic activity, volcanism, and the formation of geological structures. In the same way, Odum conceptualized the energetic value of natural resources such as water, minerals, and fossil fuels in terms of the past energy transformations “embedded” within them (it refers to all the energy used up in the past, not their current energy content). In doing so, Odum's system thinking emphasized how energy flows and transformations profoundly shape ecological production, where human societies are considered as ecological systems as well.

Odum's focus on energy partly comes from his concern about the complexity of social-ecological systems, which he believed needed a simplified, systemic perspective that allowed to see and understand general processes through a *Macroscope* (Odum, 1996). From this perspective, energy represents not the sufficient explanation of all material phenomena but an essential and unified one. Central to Odum's thought is the concept of energy as the total amount of available energy of one form, typically solar, required, both directly and indirectly, to produce a given good or service (Odum, 1996). Beyond accounting for all the required energy, Odum considered the varying quality of different energy forms, understood as their relative capacity to perform useful work. This led to the concept of an energy hierarchy, where higher-quality energy sources, such as electricity or fossil fuels, can drive more complex processes compared to lower-quality forms like dispersed heat. Through these analytical categories, Odum analyzed social systems as energy systems, unavoidably constrained by the laws of thermodynamics. Therefore, Odum (1971) argued that economic production is not merely a function of labour and capital, as conventional economic models suggest, but is ultimately constrained by the availability, quality, and organization of energy flows within the biosphere.

Odum's pioneering contributions to ecology introduced metabolic analysis as a framework to understand ecosystems as systems of interwined production and consumption processes, where energy and materials involved are complementary but non-linearly linked (Odum, 1971). He emphasized that ecological cycles do not merely repeat themselves but evolve in a spiral-like pattern, where each iteration of production and consumption alters the system structure, leading to increasing complexity or reorganization, while degrading energy quality in accordance with the second law of thermodynamics. Applying this metabolic perspective to economics grounds economic analysis in biophysical reality, pointing out that no energy or material transformation occurs without entropy increase and the generation of waste byproducts. These principles are essential for understanding economic production within the biophysical domain: (i) consumption residues and waste byproducts can be partially reintegrated into ecological cycles in transformed forms (for instance, decomposed organic matter contributes to soil fertility) but this reintegration depends on the system's regenerative capacity and ecological thresholds; (ii) when resource extraction and industrial processes generate waste beyond the assimilative or regenerative capacity of ecosystems, natural metabolic cycles are disrupted, leading to environmental degradation and loss of systemic resilience. Odum (1971) was concerned that the contemporaneous discussions on the mainstream economy often overlooked these biophysical realities, framing resource efficiency in purely technical or market-based terms while ignoring the deeper metabolic constraints imposed by the laws of thermodynamics. In natural ecosystems, decomposers and detritivores play a fundamental role in facilitating the recycling of organic matter, enabling nutrients and energy to be partially reintegrated into productive processes (Odum and Barrett, 2005). By contrast, capitalist industrial economies systematically disrupt these ecological processes, externalizing waste and pollution rather than reintegrating them.

### 2.2. The energetic history of human societies

Central to Odum's conceptualization of emergence is the concept of

<footnote n="2">² Most recent agreements place a tripartite as the original energy sources: sunlight, geothermal energy and the dissipation of gravitational potential. See *Ecological Modelling Volume 339*.</footnote>
“transformity”, a quantitative measure that expresses the amount of solar energy required, directly and indirectly, to generate one unit of a given energy form (Odum, 1988; 1996). This concept presents the existence of an energy hierarchy, where different forms of energy vary not only in quantity but also in quality, e.g. their relative capacity to perform useful work. For example, while diffuse solar radiation constitutes the foundational energy input at the base of this hierarchy, energy forms such as plant biomass, animal energy, human labour, and industrial fuels represent progressively higher transformities. A single joule of coal, for instance, embodies approximately 40,000 solar emjoules, i.e., 40E3 sej/J, reflecting the cumulative energy transformations from lower to higher hierarchical levels (Odum, 1996). Therefore, understanding the energetic foundations of social-ecological systems requires considering both the total amount of energy involved and its quality, expressed through transformity. This framework allows for tracing the hidden energetic history embedded in human labour, technology, and resource use, situating economic activity within the broader constraints of bio-physical reality.

The metabolic perspective enabled Odum to reinterpret ecological and socio-economic systems, but also human culture and religions, as energy hierarchies governed by fundamental thermodynamic principles (Odum, 1977). One of his most influential and debated contributions is the formulation of the Maximum Empower Principle, which he described as an extension of existing thermodynamic laws to complex, self-organizing systems (Odum, 1988, 1996). Building on Lotka's work on energy and biological evolution (Lotka, 1922),<fnref n="3" /> the Principle of Maximum “Empower” posited that systems which maximize empower, the flow of available energy previously transformed and embodied in a system, tend to prevail over alternatives in competitive environments. Unlike simple notions of maximizing energy throughput or efficiency, the Maximum Empower Principle emphasizes the importance of organizing and concentrating energy in forms that support complexity, information storage, and long-term resilience (Brown, 2025). Higher empower reflects the ability of a system to mobilize and sustain energy of higher quality or transformity, enabling it to develop advanced structures and capabilities (Brown and Ulgiati, 2004; Odum, 1996). In this framework, natural selection operates not only at the biological level but also at the level of ecosystems and socio-economic structures, favoring those configurations that optimize the capture, transformation, and use of available energy across scales (Odum and Odum, 2001).

Rooted in biophysical rather than social dynamics, by applying his energy analysis to human history, Odum (1971) traced the history of human economies as successive stages of energy intensification, which resembles Marxist historical materialism, which emphasizes that shifts in productive forces drive socio-economic transformations: (i) hunter-Gatherer societies functioned with low energy intensities, primarily relying on direct solar inputs via plant-based and animal resources; (ii) the agricultural revolution (~10,000 BCE) marked a major energetic shift, concentrating energy flows through domestication and surplus production, but also introduced new ecological vulnerabilities and social hierarchies, and (iii) the industrial revolution (~18th Century) marked a profound transformation in humanity's energy regime, as fossil fuels enabled a drastic intensification of energy flows and productive capacity. This unprecedented concentration and mobilization of high-transformity energy sources exponentially increased energy throughput, facilitating the expansion of socio-economic complexity, technological development, and population growth. In this progression, Odum identified a fundamental contradiction: while economic expansion depends on sustained access to high-quality energy, the overexploitation of renewable resources, unsustainable exploitation of finite resources, and the disruption of natural energy cycles progressively destabilize the ecological systems upon which long-term societal

viability depends. Therefore, industrial production dramatically increased productivity at the cost of ecological destabilization.

# 3. The economic valuation

## 3.1. Real wealth and the energy theory of value

As mentioned in the introductory sentence of this article, Odum was concerned about how to measure value to promote a sustainable management of natural resources (Odum and Scienceman, 2005). He argued that conventional economic metrics, especially monetary valuation, obscure the biophysical foundations that sustain economic processes. Explicitly, Odum (2007) observed how for a long time, resource inputs were not as limiting as labour (proportional to population) and capital (capital assets and the money to build them) but considered unlimited provided by exogenous systems. For this reason, he argued that market prices fail to reflect the ecological and energetic costs involved in transforming energy and materials into economic outputs, because they completely ignore the energy-labour provided by nature. In his view, real wealth should not be defined in monetary terms, but in terms of energy, the total amount of available energy required, directly or indirectly, to make a product or sustain a system (Odum, 1996). For Odum, real wealth derives from the embedded work of nature and society. Through his emergency accounting framework, he introduced a bio-physical perspective that reconceptualized the metabolism of economic-ecological systems.

Building on his conceptualization of energy hierarchies, Odum described industrial economic systems as those which concentrate lower transformity energies, including fossil fuels and mineral resources, into higher ones. While Odum emphasized the energetic basis sustaining socio-economic complexity, subsequent ecological political economy scholars have connected these patterns to global resource appropriation from peripheral regions (Corsi et al., 2024). This concentration of energy, therefore, enables socio-economic complexity but also exacerbates global ecological inequalities, reflecting structural patterns of core-periphery resource appropriation (Hornborg, 2009; Warlenius, 2018). To illustrate the similarities between ecosystems and society, Odum simulated how resource-constrained systems tend to exhibit oscillatory boom-and-bust dynamics (similar to predator-prey models) when driven by growth imperatives (Odum, 1988; 1996). In this model, capitalism functions as an energy-transforming system driven by positive growth rates, which inevitably collides with biophysical limits. Odum described this dynamic as “energy cannibalism”, a process in which different components of the system increasingly compete for diminishing energy resources, undermining long-term stability. This internal competition often mirrors broader patterns of unequal energy and resource exchange between urban and rural areas, and more profoundly, between core and peripheral regions of the global capitalist economy.

Despite these critiques of monetary valuation, it is unclear to what extent Odum advocated for an “energy theory of value”, a debate that continues today. While Odum briefly invoked the term (Odum, 1983, p. 252), he did not systematically develop such a theory. His work oscillates between two complementary but distinct positions: on the one hand, he rejected market willingness-to-pay as an adequate measure of real wealth (Odum and Odum, 1976; Odum and Scienceman, 2005); on the other, he developed emergency accounting to provide a biophysical-based metric capable of comparing the energetic foundations of goods, services, and socio-economic systems (Odum and Arding, 1991; Scienceman, 1992). This ambiguity explains the polarized interpretations within the literature. Some have read emergency accounting as an operationalization of an energy-based theory of value. Others interpret it instead as a diagnostic framework: not a redefinition of value in the Marxian or neoclassical sense, but an accounting device that highlights the structural disconnect between economic valuation and the biophysical processes that sustain it. Emergency does not theorize social

<footnote n="3">³ The analysis of evolution from an energy perspective can also be considered part of Lotka's and Odum's legacies (Brown et al., 2024).</footnote>
relations beyond how value becomes money, wages, profit, or prices, nor
how it is socially distributed. Instead, it offers a biophysical accounting
of the work of nature and society in producing goods and services and
maintaining complex systems.

When representing both money and energy flows in this energy
system diagrams, Odum identified what he termed an inverse relation
between market prices and energy values: money flows toward sellers
or providers, while the actual energy and materials, the biophysical
work performed by ecosystems and human labour, move away from
natural resource bases, often depleting or damaging their capacity to
sustain future production (Odum, 1996; Odum and Scienceman, 2005).
Odum's approach, therefore, allows to identify the asymmetric ex-
change of biophysical resources in market exchanges that are not re-
flected in monetary transactions. From this perspective, capitalist crises
are not merely financial anomalies but expressions of deeper contra-
dictions between the pursuit of endless monetary accumulation and the
thermodynamic constraints that govern ecological systems. In Odum's
later works he advocated for managing the inevitable energy yield
decrease through a 'prosperous way down', guided by pulsing dynamics
and adaptive strategies that leverage existing socio-economic tools,
including aspects of capitalism, to foster resilience during transitions
(Odum and Odum, 2001; Ulgiati, 2004). This framework has been used
to sustain contemporary debates on degrowth (Kallis, 2011).

## 3.2. *The energy basis of the economy in ecological economics*

Odum's environmental accounting is foundational for the heterodox
movement of economists that since the 70s have reclaimed the inter-
nalization of environmental problems in economic models. The
Ecological Economics school recognizes Odum, alongside Georgescu-
Roegen, as precursors of building a biophysical foundation for eco-
nomic analysis grounded in the laws of thermodynamics (Pirgmaier,
2021; Guarino et al., 2023a). In particular, Herman Daly and Robert
Costanza, students respectively of Georgescu-Roegen and Odum,
devoted the first part of their academic career to the analysis of energy
and materials transformation in socio-economic systems (Costanza,
1978; 1979; 1980; 1981; Daly, 1968; Daly, 1978). For instance, Cos-
tanza (1979) analyzed the correlation between the economic output,
assessed through the price mechanism, and what he termed "embodied
energy". Although different, embodied energy recalls the energy
concept of Odum, referring to the direct and indirect energy cost
required to the production of goods and services exchanged in markets
(Costanza, 1980; Brown and Herendeen, 1996). Costanza (1980)
expanded his research question and wondered whether natural re-
sources are external to the economic system and thus independent. That
is, is it possible to consider economic production disregarding energetic
limits? As Costanza (1980) found, the correlation between embodied
energy and economic output demonstrates how this is physically
impossible because, as now is widely recognised (Parrique et al., 2019;
Guarino et al., 2023b), it's impossible to have infinite growth on a planet
of finite resources.

From these foundational contributions, two main currents evolved
within ecological economics concerning the energetic foundations of
economic production and exchange (Pirgmaier, 2021). The Energy Re-
turn on Investment (EROI) community, pioneered by Charles Hall,
which focuses on net energy availability, emphasizing the ratio of en-
ergy extracted to the energy required for its extraction and production
(Hall et al., 1986; Murphy and Hall, 2010; Røpke, 2004). EROI analysis
aims to provide critical insights into the long-term sustainability of
energy-dependent economies, emphasizing how diminishing energy
returns can constrain economic growth and societal complexity (Hall
et al., 2014). The second school, which Pirgmaier (2021) refers to as the
Exergetic Community, posits that exergy serves as a reliable indicator of
available work, incorporating both the quantity and quality of energy
utilized in production (Ayres and Knees, 1969). Exergy is fundamentally
an entropic measure, representing the difference between the energy

available at the start of a process and the residual energy that is no
longer available for work at the end.

Odum's work also influenced broader frameworks such as natural
capital and ecosystem services. By emphasising the biosphere as the
ultimate support system for human economies, he laid the groundwork
for understanding ecosystems as the primary providers of energy, ma-
terials and services that are indispensable to economic processes (Odum,
1971, 1996). Indeed, the ecosystem services valuation and the concept
of natural capital (Costanza and Daly, 1992; Costanza et al., 1997) can
be considered as evolutions of the embodied-energy theory that incor-
porate more socio-economic dimensions (rather than expressing every-
thing in a common unit). Indeed, these frameworks reflect an insight
shared by Odum and Costanza: that the economy is embedded in and
constrained by the energy flows and ecological processes of the
biosphere.

Despite their conceptual differences, these schools often share the
ambition of integrating biophysical assessments of goods and services (e.
g., exergy, EROI or ecosystem services) into economic frameworks,
attempting to reconcile ecological limits with the logic of market-based
valuation. A notable exception is C.A.S. Hall, who has consistently
criticized the growing emphasis on the monetary valuation of ecosystem
processes within ecological economics (Melgar-Melgar and Hall, 2020).
The focus on biophysical metrics have advanced our understanding of
the biophysical constraints to economic growth, but their technical focus
often sidelines the social and political dimensions of ecological crises.
Specifically, Marx's analysis of how energy, labour, and resources are
historically appropriated, distributed, and exploited within relations of
power is frequently marginalized. As a result, these approaches not only
risk depoliticizing debates on sustainability, obscuring the structural
roots of inequality and exploitation behind the social-ecological crisis,
but also diminish the importance of collective and democratic
decision-making in shaping humanity's metabolic relationship with
nature. It has to be mentioned, however, that ecological economics is
committed to value pluralism (monetary, biophysical, relational), and
increasingly suggest their integration for more transparent and
comprehensive decision-making (IPBES, 2022).

## 3.3. *Emergy accounting and labour theory of value: convergences and tensions*

According to Pirgmaier (2021), the distinction between labour and
energy-based approaches to value echoes the classical division between
Ricardo and Smith regarding the labour theory of value. Aligning with
them, Marx also rooted value in labour, but provided a third, distinct
framework that shed light on the antagonistic character of capital
accumulation and labour reproduction. Indeed, like Smith and Ricardo,
Marx regarded labour as the ultimate source of value, specifically, that
exchange value in the capitalist mode of production represents the
embodiment of human labour-time (Napoleoni, 1976). However, Marx's
originality lies in his historical-materialist lens, which enabled him to
grasp that behind the quantitative assessment of labour time lies a his-
torically specific social relation shaping the organisation of labour. For
Marx, this abstraction of labour detaches value from its material roots,
organising economic activity under capitalist relations of production
(through commodification and profit-maximisation) rather than
through the requirements of socio-ecological reproduction (Foster and
Holleman, 2014). His labour theory of value therefore locates value not
in energy inputs per se, but in the abstract commensuration of qualita-
tively different concrete labours through market exchange (Marx,
1992). Crucial here is Marx's distinction between concrete labour (the
actual metabolic interaction between humans and nature) and abstract
labour (the reduction of all labour to a common denominator under
capitalism). This abstraction is not merely conceptual but material,
enacted through commodity exchange, and mediating humanity's
metabolic interchange with nature (Guarino and Yasin, 2025). Marx
(1992) distinguished two categories of value: (i) use-value as the
material utility of a commodity, its ability to satisfy human needs or
wants, grounded in its qualitative properties as a product of concrete
labour; and (ii) exchange-value as the quantitative proportion in which a
commodity trades against others in the market, expressing the abstract
social labour time required for its production under prevailing societal
conditions. This tension lies at the heart of Marx's critique of political
economy.

Historical debates on energy and value offer a bridge between Marx's
analysis and later biophysical approaches. In the late 19th century, S.
Podolinsky attempted to integrate thermodynamic principles into
Marxist political economy, arguing that agricultural labour could be
understood as a process that concentrated solar energy in useful forms.
His pioneering work anticipated aspects of energy economics and
ecological thought. As Martínez-Alier and Naredo (1982) note, Podo-
linsky's proposal sought to reconcile the labour theory of value with
energy accounting, but Marx and Engels responded cautiously, empha-
sising that while energy flows were indispensable to production, value in
capitalism was a social relation grounded in human labour time (see
Foster and Burkett, 2016). Podolinsky's efforts anticipated certain
themes later explored in energy analysis and ecological economics,
particularly the attempt to measure productive processes in energetic
terms. However, both Martínez-Alier and Naredo (1982) and Foster and
Burkett (2016) recognize, his approach also revealed the enduring dif-
ficulty of reconciling biophysical metrics with the social theory of value
at the core of orthodox Marxist political economy.

In this light, Odum's (1996) energy accounting can be seen as
echoing aspects of Podolinsky's original intuition: the search for a uni-
fying metric to capture the material basis of production. For Marx, so-
cially necessary labour time constituted the measure of value under
capitalist conditions; for Odum, energy offers a biophysical analysis
that integrates both human and natural contributions to real wealth
using a common unit (Odum and Odum, 2001). Despite their distinct
epistemologies (Odum's universal systems ecology versus Marx's his-
torical materialism) both frameworks illuminate the disconnection be-
tween capitalist valuation systems and the material-energetic-labour
foundations of economic activity.

Odum's approach highlights how monetary systems obscure the
biophysical work underpinning production, exposing capitalism's ten-
dency to deplete ecosystems by extracting high-quality energy from
peripheral regions, transforming it into market value while eroding
natural productivity. Marx's framework, in contrast, foregrounds the
role of property relations, class structures, and labour organisation in
shaping the human-nature metabolism, showing that ecological crises
are fundamentally social in origin (Foster, 1999; Foster and Holleman,
2014). Nonetheless, both approaches converge on two fundamental di-
mensions of economic production. First, every commodity embodies a
form of work, whether human labour or biophysical energy trans-
formations, forming the real basis of wealth, often concealed by market
abstractions. Second, capitalism's drive toward infinite market expan-
sion systematically disregards the finite energetic, material, and
ecological resources upon which economic activity relies, by treating
value as an abstract, self-replicating logic detached from biophysical
constraints. For Marx, this contradiction manifests as a "metabolic rift"
(Foster, 1999), an irreparable disruption in the regenerative cycles of
socio-ecological reproduction, rooted in capital's dual exploitation of
labour and nature, what he described as the "robbing" of both the
worker and the soil (Marx, 1981, pp. 949-950). Odum's systems ecology
and energy accounting arrive at a parallel diagnosis through a different
path, underscoring the energetic imbalances that accompany economic
expansion.

# 4. The Eco-Marxist debate on Odum

## 4.1. *The metabolic rift through the lenses of Odum's systems ecology*

Odum's energy analysis and Marx's labour theory of value represent

two distinct but intersecting critiques of capitalism's ecological con-
tradictions. While Marx (1981, 1992) revealed how capitalist social
relations distort and exploit nature and labour through the commodity
form, Odum approached the same systemic crisis from the perspective of
energy systems, focusing on the energy-matter throughput that sustains
economic activity. According to Foster and Holleman (2014), Odum's
systems ecology can meaningfully contribute to understanding capital-
ism's ecological crisis, particularly the metabolic rift, and building
Odum-Marx dialects could emerge as a complementary framework of
understanding capital ecological contradiction. They argue that both
frameworks reveal capitalism's systematic contraposition of "real
wealth", whether labour (Marx) or energy (Odum), and the abstract
market-driven economic wealth. Odum's energy analysis provides a
powerful tool to expose the material asymmetries that sustain the cur-
rent mode of production. In particular, Odum's studies demonstrate that
core economies extract "several hundred percent higher" energy per
dollar from peripheries compared to what they invest (Odum 2007,
276-7), an empirical pattern that aligns with Marx's diagnosis of labour
exploitation and the metabolic rift.

The metabolic rift theory describes how capitalism disrupts natural
cycles through the separation of town and country, leading to resource
depletion and ecological degradation. It stems from Justus von Liebig's
mid-19th century critique of industrial agriculture as a robbery system,
which revealed how industrial agriculture severed the nutrient cycle,
with soil nutrients (nitrogen, phosphorus, potassium) being extracted
from rural areas and accumulating as waste in urban centers. For Marx
(1992), this metabolic disruption was not merely a technological or
agronomic failure, but rather the inevitable consequence of capitalism's
social organization, particularly its separation of town and country, and
its treatment of both labour and nature as mere factors of production.
Odum contributed to this understanding by conceptualizing these
metabolic disruptions through the lens of energy systems, developing
methods to quantify the energy flows underlying economic exchanges,
analyzing it as a systemic feature of energy hierarchies: the tendency for
industrialized "sink" regions to draw resources from lower-entropy
"source" regions (Odum 1996; Odum and Odum 2001). Such extrac-
tion implies that these resources are not available for local feedback and
local production. Odum's energy systems perspective thus complements
Marx's analysis by providing measurable, biophysical-based indicators
of unequal exchange, resource extraction, and ecological degradation,
which can lead to increasing inequality over time.

## 4.2. *The risk of a biophysical reductionism*

Odum conceptualization of ecologically unequal exchange has faced
significant critique from Alf Hornborg, a central figure in contemporary
ecological economics scholarship (Corsi et al., 2024). Hornborg (1998;
2014) argues that Odum's energy framework conflates biophysical
flows with economic categories, particularly by framing energy flows
(wrongly equating emergency to energy flows) as "underpaid use values"
confuses physics with economics. A similar critique to that of Marx and
Engels to Podolinsky (see Martínez-Alier and Naredo, 1982 and Foster
and Burkett, 2016). For Hornborg, "use value" is inherently cultural,
tied to what societies deem useful, and not measurable in joules or solar
equivalents. Indeed, he maintains that unequal exchange is not a matter
of undervaluation between monetary values and biophysical (neither
labour time) quantities (Hornborg, 2025). By reducing ecological
exploitation to discrepancies between energy and market prices,
Odum's framework risks legitimizing the very market logic it seeks to
critique (Hornborg, 1998, 2014). Hornborg further criticizes Odum's
energy hierarchies, which position industrial economies as "sinks"
draining resources from peripheries, for neglecting the role of social
power in shaping energy flows. Odum's thermodynamic analysis, he
argues, reduces historical processes like colonialism to universal energy
laws, obscuring how capitalism's social relations (e.g., wage labour,
property regimes) structure exploitation. This "physico-reductionism,"
Hornborg (2014) warns, naturalizes inequalities as inevitable outcomes of entropy rather than products of human agency.

Additionally, Hornborg (2014) argues that Odum's concept of
emergency, akin to Marx's labour theory of value, represents a "meta-
physical" construct leading to two problematic implications: one is that
two identical craft objects should have different emergency values
depending on the efficiency of the craftsman. Another is that the emergency
value of a junk car, having been subjected to years of maintenance,
should be higher than that of a brand new one. For these reasons,
Hornborg advocates abandoning value theories in ecological economics
altogether, thus avoiding the "normative" baggage of value theories that
aim to propose how value should be measured instead of explaining how
society currently assigns value. He argues that ecologically unequal
exchange should be analysed through direct, descriptive metrics such as
material flows or ecological footprints (Hornborg, 2014; 2025). He links
this critique to Georgescu-Roegen's entropy law, emphasizing that
ecological debt, unlike financial debt, is biophysically irreversible and
cannot be compensated through market mechanisms (Hornborg, 2014).
Moreover, he challenges Foster and Holleman's (2014) Marx-Odum
synthesis, warning that framing ecological exploitation as "underpay-
ment" risks legitimizing harmful practices by suggesting that they could
be remedied through price adjustments. Instead, Hornborg attributes
ecological exploitation to the thermodynamic logic of monetized trade
itself, where low-entropy resources (e.g., oil, minerals) are exchanged
for high-entropy money, a dynamic perpetuated by any growth-oriented
system, capitalist or otherwise (Hornborg 1992, 2014).

While we share Hornborg’s concern about naturalizing inequalities,
we believe that the “two problematic implications” of emergency analysis
can be interpreted differently. First, two identical crafts having different
emergency aims to reflect to what extent different production systems are
more or less environmentally sustainable by analyzing the total energy
required as well as its local/imported and renewable/non-renewable
origin. This can help to inform policy-making, as already done by the
use of other assessment tools like life cycle assessment, material flow
analysis or ecological footprint to compare different production systems.
Yet, emergency can be considered “a multi-dimensional environmental
footprint, much more comprehensive than land, carbon or water foot-
prints” given its consideration of the interconnections between “the
environment and the socio-economic system, following the flows of
energy, materials and information among them without disregarding
their cumulative available energy due to the biosphere’s support”
(Munoz-Ulecia et al., 2023). Regarding the second problem, this is a
matter of choosing a proper functional unit (a common mistake in
environmental assessments). In this case, choosing kilometers as a
functional unit will probably reflect how a new car has higher emergency
than a junk car.

5. Discussion and conclusion: towards a critical synthesis of energy, ecology, and power

We can summarize the epistemological divide as a juxtaposition
between a biophysical determinism and a social reductionism. On the
one hand, from Odum's energy systems perspective, global capitalism
can be seen as an "imperial" system of unequal energy exchange that
stems primarily from biophysical and thermodynamic principles (Odum,
1996; Odum and Odum, 2001). In his framework, emergency flows reveal
structural patterns whereby industrialized regions extract disproport-
tionately high levels of embodied energy from peripheral, resource-rich
areas. Crucially, however, Odum interprets these dynamics as systemic
outcomes of thermodynamic imperatives, largely independent of spe-
cific historical, social, or class-based processes. On the other hand, Marx
(1992) located the roots of unequal exchange within historically
contingent social relations of production, particularly the mechanisms
by which capitalism creates "superprofits" through the underpayment of
rural labour, facilitated by workers' partial dependence on
non-capitalist subsistence. While Odum and Scienceman (2005, 41)

observed similar patterns of unequal exchange, they attributed them
primarily to differences in "environmental subsidies", the unpaid energy
inputs from local ecosystems that lower production costs in
resource-rich regions, rather than to relations of exploitation or value
extraction as emphasized in Marxian analysis. This epistemological
contrast reveals that Odum and Marx analyses constitute complemen-
tary causal narratives for the observed dynamics of unequal exchange.

H.T. Odum's legacy offers insights for rethinking how societies interact with ecological limits. His work in systems ecology and environmental accounting emphasised the importance of energy flows and the support of ecosystems to sustain economic activity. By quantifying the available energy embedded in economic production and trade, Odum exposed the significant discrepancy between the monetary valuations of the market and biophysical reality. However, critical debates within ecological economics and political ecology suggest that comprehending social-ecological degradation should go beyond measuring energy flows; it requires addressing the social structures and power relations that drive environmental exploitation. Eco-Marxist perspectives complement Odum's insights by illuminating how the capitalist dynamics of accumulation and profit maximization systematically undermine ecological integrity and accelerate resource depletion. This convergence invites further dialogue between systems ecology and political ecology to continue thinking about sustainability within bio-physical and social planetary boundaries.

Declaration of generative AI and AI-assisted technologies in the
writing process

During the preparation of this work authors used Deepseek in order
to improve the writing. After using this tool/service, authors reviewed
and edited the content as needed and take full responsibility for the
content of the publication.

Funding sources

This research did not receive any specific grant from funding
agencies in the public, commercial, or not-for-profit sectors.

CRediT authorship contribution statement

Raffaele Guarino: Writing – original draft, Resources, Formal analysis, Conceptualization. Enrique Muñoz-Ulecia: Writing – review & editing, Supervision, Conceptualization.

Declaration of competing interest

The authors declare that they have no known competing financial
interests or personal relationships that could have appeared to influence
the work reported in this paper.

Data availability

No data was used for the research described in the article.

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