Cement and concrete underpin modern societies, yet their true resource demands and the dynamics that govern their efficient use remain poorly understood. Two recent studies suggest that the most powerful levers for change may not lie inside the cement plant at all.
Concrete is the most widely used man-made material on Earth. Each year its production exceeds that of every other material by a wide margin: roughly 20 times that of steel and 40 times that of solid wood products1. The physical foundation of cities, infrastructure and housing on every continent relies on concrete. And yet, when it comes to sustainability, concrete is typically discussed in narrow terms, such as the need to improve cement chemistry, kiln efficiency and process emissions. That focus overlooks both the sheer scale of resources mobilized by the whole concrete cycle and the socio-economic forces that ultimately drive how much concrete societies consume2.
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The growing challenges posed by the urgent need to mitigate climate change, to manage the impacts of rapid urbanization in less developed regions and to renew infrastructure in ageing economies have turned cement production into one of the most prominent hard‑to‑abate sectors. Research and policy have largely responded by focusing on improving production processes3: clinker substitution, use of alternative fuels, electrification of manufacturing and, increasingly, the adoption of carbon capture technologies. These efforts are essential, but they largely treat demand for concrete as fixed or exogenous. Meanwhile, pressures on minerals and resources continue to intensify4, with extraction activities often poorly monitored and weakly governed given the challenging socio-political context in which they take place.
Two recent Analyses in Nature Sustainability invite readers to look at the cement–concrete cycle as a full socio-economic system, rather than just as a chain of industrial processes. The Analysis by Tong Zhang and colleagues examines changes in material efficiency across 184 economies and finds that improvements over time are driven predominantly by demand-side dynamics, including changes in construction intensity (concentration of resources and materials), building lifetimes and the patterns through which societies provide infrastructure, rather than by gains in production efficiency alone. In other words, how societies plan, design and use buildings has a much larger role in improving resource efficiency than any incremental technological progress at the level of cement plants. The other piece, by Sabbie Miller and colleagues, exposes how much of concrete’s footprint is hidden from conventional accounting. By tracing not only the direct mineral, energy and water inputs into concrete production worldwide, but also the losses and inefficiencies along extraction and supply chains, the authors estimate that concrete-related activities mobilized approximately 66 gigatonnes of resources in 2019 alone, more than double previous figures based only on direct inputs. Overburden from mineral extraction, energy conversion losses and water requirements that fall outside standard system boundaries together amount to a substantial, and largely invisible, environmental burden.
The insights from these articles fundamentally alter how society should conceive efficiency and mitigation strategies for concrete. If demand-side drivers dominate improvements in material efficiency, and if total resource use is far greater than currently assumed, then a narrow focus on cleaner production risks missing the most powerful levers for change. Even when producing low-carbon cement, the environmental pressures will be substantial if cement is used in excessive quantities, because of structures not being designed to last long or being developed through inefficient construction practices.
This is where the focus should arguably move next. A shift in perspective is needed. How can society move towards a balance between optimizing production and governing demand, considering multiple factors such as service life of buildings, avoiding overdesign, improving space use efficiency and rethinking renovation over replacement? And what would it take to (better) monitor material and resources, particularly for locally sourced cement aggregates? These can be uncomfortable questions, in part because they reach into planning cultures, professional norms and political choices about how cities and infrastructure are built, or because they cut across different disciplines and ministries.
Concrete will remain indispensable to human development. The question is no longer how to make more of it better, but how to decide when, where and how much concrete is needed, based on monitoring and continuous assessments informed by research. Making its invisible impacts visible is a necessary first step towards a sustainable built environment.
