Intervention – “Sedimentary Justice: A Planetary Politics of Shifting Sediment”

Kate Dawson, Department of Geography and Environment, London School of Economics and Political Science


The geography of the Earth has never been stable. As the deep history of the planet would indicate, Earth has undergone many vast transformations, re-emerging in new states that present evolving potentialities for the (non-)living (Clark and Yusoff 2017). As geologist Jan Zalasiewicz remarks, “the Earth seems to be less one planet, rather a number of different Earths that have succeeded each other in time, each with very different chemical, physical, and biological states” (quoted in Clark and Yusoff 2017: 5). The vast transformations are undergirded by the active strata of the Earth’s core, which by unleashing its energy to the surface, produces new land, destroys other lands, and gives rise to vast new seas. Set in the context of this deep planetary energy are other, and indeed related, processes of land transformation on the face of the planet. Governed by gravity, winds, air, oceans, and rain, earthly sediment is shifted from mountains, rocks, reefs, and coastal cascades, to new homes in rivers, valleys, lakes, and seas, transforming itself and the landscapes it passes through. Indeed, mobility is the central facet of sediment. Less defined by the type or size of material, sediment is solid Earthly material, transported across space. Over time, sediment – ranging from grains of sand, to resounding boulders – settles, compacting into new sedimentary formations, awaiting its destiny as uplifted land in the deep future. These sedimentary cycles keep Earthly materialities shifting and our planetary landscapes dynamic. While complex and place-dependent, this sedimentary dynamism also delivers several services, including the production and ongoing protection of (non-)human habitats, soil formation, the provision of nutrients and minerals to nearby ecosystems, and water resource maintenance. Yet, this dynamism also poses significant challenges to the management of socio-natural environments, in that sedimentary changes grounded in particular localities can generate far-reaching shifts across space and time. This makes sedimentary movements deeply contested processes.

Despite the grand scales at which such sedimentary systems have long operated, humans are now among the biggest of the earth-moving forces. Indeed, estimates indicate that (some) humans are now consuming more than twice the total annual volume of sediment carried by the world’s rivers (UNEP 2019), bespeaking the widely-debated Anthropocene thesis of a geological epoch marked by the forces of (parts of) humanity. Used for concrete construction, land reclamation, glass, and electronics, sediments of the Earth are being shifted across space, near and far, in vast volumes, in a continuous bid to build worlds, share ideas, and imagine new futures. Yet, within this regime of earth-moving, sedimentary accretions remain set in the context of sedimentary losses. The purpose of this Intervention is to open space for thinking across such sedimentary accumulations, gains, losses, and dispossessions in our present geological epoch of unprecedented human-induced earth-moving. Taking sediment as an unstable material process, the Intervention invites reckonings with the socio-natural politics of material mobility, asking that analyses might work through the power relations embedded in the claims over, access to, and security of, sediment. Recognising that there are significant stakes implicated in sedimentary gains and losses, the Intervention asks that we think more closely with the politics of shifting sediment/sediment shifting. Indeed, it asks that we think with the politics that governs sedimentary in/security, engaging with the (dis-)placement dynamics through which sediment emerges, depletes, shifts, and reforms. In support of this endeavour, it offers the notion of sedimentary justice as both a lens through which to unearth existing politics and as a critical tool for imagining future sedimentary relations that allow for conditions of multispecies thriving.

Gains and Losses

According to the Dutch research group, Deltares (2018), since 1985, Earth has acquired 13,565 square kilometres of coastal land – equalling the size of Jamaica. Among the largest of the world’s sedimentary importers is Singapore, who relentlessly devours sand in the name of its ambitiously expanding territory. Indeed, set in the context of a colonial history of land reclamation, Singapore’s has expanded by 22% since 1965, with plans to expand by another 5,600 hectares by 2030 (Faciolince 2020). Singapore is not alone in its expansive practices, however, as land reclamation has become an increasing feature of urban coastal development more broadly. According to Sengupta et al.’s (2018) recent analysis, between the mid-1980s and 2017, an additional 1,249.78 square kilometres of land was reclaimed in the world’s coastal megacities. Shanghai tops the list, reclaiming 587 square kilometres in the same period. The list extends beyond Asia however, with Buenos Aires, Istanbul, Lagos, Mumbai, and Lima also extending their land mass. This practice has informed urban plans across the world, with investors and politicians envisioning vast new urban extensions, marked by high-end living, luxury consumption spaces, and incredible profits for developers. In this vein, sedimentary accumulations in urban coastal zones map neatly onto the accumulation of profits (Jamieson 2021).

Yet, these grand land extensions are set in the context of an accelerating loss of land at the world’s coastal and riverine edges. A significant, and indeed growing, set of sedimentary losses can be understood as the direct impact of sedimentary gains elsewhere. For instance, the expansion of Singapore’s landmass through ongoing rounds of land reclamation has come at a cost of a significant loss of land across South East Asia, in what Jamieson (2021: 288) describes as a “colonial extraction of territory”. Despite various bans on exports from Indonesia, Malaysia, and Cambodia, sand continues to reach the shores of Singapore, through both legal and illegal channels (Global Witness 2010). The documentary Lost World, by Cambodian filmmaker Kalyanee Mam (2018), speaks to this mass sedimentary displacement, in which more than 80 million tons of sand have been extracted from the riverine spaces of Cambodia alone. Indeed, this deeply emotional visual rendition of disappearing land reveals the story of a Cambodian island, from which sand has been dredged – sand destined for the expanding territory of Singapore. Juxtaposing the shifting shores of both urban accumulation and island loss, the film examines the socio-ecological impacts on the disappearing island: mangrove destruction, depleting crab stocks, loss of livelihoods, and the gradual dissipation of the multispecies communities which have long resided there. These are dynamics repeated elsewhere, both far and wide, operating at both regional and global scales, yet also within more local spaces. Indeed, as is widely understood, the extraction of sediment from a coastline or river generates erosion impacts further along the coast or downstream (Jonah et al. 2015; Koehnken and Rintoul 2018).

We can also understand sedimentary loss as a process underpinned by erosion, storm surges, and subsidence, which together are accelerating in a shifting climate. While planetary in scale, the threats of this kind of sedimentary depletion are felt unevenly, with huge swathes of low-lying land facing accelerating conditions of sedimentary insecurity. Indeed, according to research at Climate Central (2014), between 147 and 216 million people reside on “land that will be below sea level or regular flood levels by the end of the century”. As highlighted above, redistributing sediment in the name of expanding territory poses direct threats to the sedimentary systems from which it is sourced, contributing to river bank collapse and erosion. Yet, there are also more complex relationships at play in relation to sedimentary mobility, which might be understood as a set of carbon-climate linkages. Firstly, in addition to the destruction of habitats, the dredging of material from marine systems releases carbon stored in sediment, contributing to carbon dioxide emissions (Slamet et al. 2018). This is a process increasingly observed in the bottom-trawling seafood industry, with scientists pointing to the mass release of blue carbon stored in ocean bed sediment, amounting to volumes equivalent to that emitted by the aviation industry (Sala et al. 2021).

While less publicised, the expanding volumes of sediment dredged from riverine and marine environments in the name of land reclamation, beach nourishment, and aggregate acquisition, would suggest that the release of blue carbon stored in sediment is an issue of significance. Moreover, the direct release of carbon remains in addition to other emissions that come with operating machinery and transporting sediment to and from sites of both production and consumption (Sala et al. 2021). As has been routinely announced, increases in atmospheric carbon dioxide leads to sea level rise and a shifting climate, marked by increased frequency and severity of weather events, like storms and flooding. Thus, sedimentary security, in places most vulnerable to climate change, is increasingly threatened. In this way, through carbon-climate linkages, we can expose the unfolding relationships that tie together spaces of sedimentary accumulation with spaces of sedimentary loss.

The multidimensionality of sedimentary relationships in the carbon-climate link might be further understood through the materiality of concrete. The concrete verticalities of expanding urban worlds can be read as massive material accumulations of sand and gravel: sediment unearthed in one place and enlivened elsewhere. As outlined here, the extraction of sediments, like sand and gravel, in one place, has direct implications for that in-situ sedimentary space – and that dredging releases carbon stored in that materiality. Yet, the sedimentary relationships embedded in concrete are multivalent. Indeed, the production of concrete itself also emits immense volumes of CO2, contributing 8% to total global emissions (Lehne and Preston 2018). In this vein, the carbon-climate linkages re-emerge. As sediment accumulates as concrete structures, in another space and time, sediment is lost. Such links are reminiscent of recent work in this journal (, in which I made a call to see the city as a set of uneven geosocial relations to be grappled, through the prism of sand more specifically (Dawson 2021). Engaging with sediment expands the spatial repertoire of geosocial relations discussed in this paper, thinking through and beyond concrete and the city, to consider the implications embedded in the vast earth-moving practices of our geological present.

Sedimentary Justice

This brief account of shifting sediment points to just a few of the dynamic relationships that undergird sedimentary accumulations and sedimentary losses. While sediment, by nature, is a shifting materiality, the increasing scale at which some humans are moving earth demands attention – in turn, forcing us to unpack the sedimentary processes through which (non-)human habitats and ways of life are under threat, while others emerge as ever-secure. It reminds us that sediment is far from a banal materiality, but rather underpins vast socio-natural landscapes on the planet, upon which we depend upon for existing, and indeed future, thriving. In this respect, sedimentary relations are deeply political and beckon much more thorough analysis. In this brief Intervention, I presented some key relationships that connect sedimentary gains with sedimentary losses. As I have suggested, at times material systems of shifting sediment mean that these losses and gains are directly implicated in each other’s existence. Yet, there are also significant indirect relationships between sedimentary accumulations and the loss of sediment elsewhere – namely, through a complex set of climatic linkages. There are rich set of possibilities for unearthing sedimentary gains and losses, beyond those discussed here. For instance, the relationships between desert greening programmes and expanding desertification elsewhere.

Within the scope of sedimentary relations, questions of justice might appear, at first glance, like a simple exercise in unpicking the dynamics between accumulation and dispossession. However, in other instances, the question of justice emerges as more complicated. Understanding why, for instance, a resident in one community might feel compelled to extract sand from a fragile river system, undermining other livelihoods and lives that depend on that system, requires a lens which can deal with the multifaceted nature of sedimentary gains and losses, set in the context of grounded histories and the inequalities of the global political economy (Lamb et al. 2019). In turn, such a lens might point to the complexity that underpins struggles over sediment, bringing to the fore a more complex notion of justice. Indeed, the benefits of securing a concrete home – which include access to finance, reduced risk of suffering from disease, securing tenure, among others (Beiser 2018) – also complicates the notion of sedimentary accumulations. Moreover, the quality of sediment also has a bearing on questions of justice. For instance, access to quantity and quality of sediment shapes who is able to build safe, secure, and sustainable dwelling environments, with those on low incomes and less able to build with high quality sediment facing greater risk of building collapse and flooding. Sediment is thus implicated in cementing further inequalities into an expanding concrete form (Beiser 2018).

To engage with such complexity, we might begin by asking a series of rudimentary questions:

  • Who/what/where benefits most intensely from sedimentary accumulations?
  • Who/what/where suffers most intensely from sedimentary losses?
  • Whose sedimentary security is made to matter?

By asking these questions, I suggest that we are better able to draw out the very real differences in gains and losses that underpin the vast scales of earth-moving currently underway on our planet. Any attempt to grapple with these questions should draw on an interdisciplinary set of concepts and frameworks, including, but certainly not limited to, environmental justice, (urban) political ecology, land grabbing, the Anthropocene and its critiques, and finally the politics embedded in postcolonial studies.

This Intervention positions sedimentary justice as an entry point through which to unearth the power relations that govern deeply uneven claims over sediment, which, in turn, allow some sedimentary systems to accumulate, while others are made to deplete. It is to this end that I offer sedimentary justice as both a lens through which to excavate the layered politics of access, rights, and security of sediment, as well as to envisage alternative sedimentary relations that bespeak multispecies thriving. In this respect, in a bid to invite reckonings with a sedimentary justice across space and time, I juxtapose two sedimentary landscapes – Greenland and Monrovia, Liberia.

Sedimentary Futures

As ice continues to melt in the Arctic, new supplies of sediment are surfacing. In particular, Greenland’s growing deltas have emerged as a potential future supplier in the face of dwindling global sand resources (Bendixen et al. 2019; Torres et al. 2021). While hypothetical, the turn to Greenland presents a series of questions for sedimentary justice. Should sediment be extracted at all, given that, if transformed into concrete buildings, we face greater – and, indeed, uneven – risks from climate change? If sediment is to be extracted and shifted elsewhere, where should be prioritised? Will sediment flow to sites of capital accumulation, extending city edges in the name of profit? Who, at large, is set to benefit from new supplies of sediment? Whose sediment is already threatened through the same processes which have given rise to Greenland’s emerging sediment?

In the West Point community of Monrovia, Liberia, questions of sedimentary justice are ever on the surface. Home to more than 60,000 of the city’s most marginal inhabitants, West Point sits on a sand dune, jutting out into the Atlantic Ocean. Today, the inhabitants of West Point face a multifaceted set of challenges, including insecure tenure, unemployment, limited sanitation facilities, pollution, depleting fish stocks, and, due to rising sea levels and beach sand mining, a rapidly eroding coastline that threatens the very sands on which the community is built. In this fragile landscape, inhabitants gather sediment from various locations, fashioning sandbags which they hope will lessen the blow of crashing waves. West Point is not alone, as many other coastal communities continue to battle with sediment. Sedimentary justice offers a way of placing these two fragile landscapes – Greenland and West Point – into productive dialogue. Beyond the scope of this Intervention, I hope this juxtaposition invites some new lines of thinking across sedimentary space and time. While complex and emergent, in the end, the notion of sedimentary justice asks that we plan for and work to enliven a more just set of sedimentary futures.


Photo by JB Dodane (@jbdodane) – West Point, Monrovia, 15 July 2013 – (CC BY-NC 2.0).


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