The methodology behind the estimate represents a significant advance in how scientists quantify the physical economy. Rather than extrapolating from sparse national statistics, the team constructed a building-level characterization that records the footprint, height, typology and inferred material composition of individual structures worldwide. By combining machine-learning classification of satellite and geospatial data with engineering relationships that translate a building’s geometry into mass of concrete, steel, masonry, timber and other materials, the researchers could weight each of the 606 million structures much as an accountant weighs each asset on a balance sheet. The result is a high-resolution global map of where material mass physically sits, from the reinforced concrete towers of East Asian megacities to the low-rise masonry neighbourhoods of Europe and the lightweight dwellings of sub-Saharan Africa.

The headline number, 835 gigatonnes, confirms that buildings dominate the material dimension of human civilization. Earlier work, including a landmark study published in the Proceedings of the National Academy of Sciences in 2017, showed that global socioeconomic material stocks rose twenty-three-fold over the twentieth century and that maintaining and expanding those stocks now requires roughly half of all annual resource use. The new building-level inventory sharpens that picture considerably by showing exactly which objects consume those resources. Buildings, it turns out, are the single largest store of anthropogenic materials, outweighing infrastructure, vehicles and machinery combined by a wide margin. Concrete and aggregate dominate the stock, followed by brick, steel and timber, with the mix varying systematically by region, income level and urban form.

What elevates the study beyond a bookkeeping exercise is its demonstration that material stock correlates strongly with urban form, and that urban form is a policy variable. Dense, compact cities with mid-rise and high-rise construction embody far less material per unit of floor area than sprawling, low-density development built with single-family homes. A detached suburban house may require several times more material per square metre of living space than an apartment in a well-engineered residential tower, because it spreads foundations, walls and roofs across a much larger footprint for the same usable area. The researchers show that cities which have grown vertically, whether in East Asia or in dense European cores, deliver housing and commercial space with markedly higher material efficiency than cities that have grown outward. The choice of urban form made today, in other words, is a choice about how many gigatonnes of stone, sand, iron and cement future generations will need to extract.

The inequality dimension of the findings is likely to spark the most debate. High-income countries hold a disproportionately large share of the global building stock relative to their populations, reflecting decades of accumulated construction, larger per-capita floor areas and heavier material specifications. Low-income countries, by contrast, face an enormous unfinished task: providing adequate housing, schools, clinics and workplaces for growing urban populations with building stocks that are materially thin. A household in a wealthy economy may be sheltered by hundreds of tonnes of embodied material, while a household in a low-income country may live within a structure embodying a fraction of that mass. Closing this material gap is a development imperative, yet it collides head-on with planetary limits, because the cement, steel and aluminium industries already account for a substantial share of global carbon dioxide emissions and industrial energy demand.

This tension frames what the study’s authors call efficiency paths. If low-income nations simply replicate the material-intensive development trajectories of the twentieth century, the global building stock could balloon in ways that climate targets cannot absorb. But the building-level database suggests alternatives. Material-efficient urban forms, compact neighbourhoods served by shared infrastructure, mid-rise construction that balances density with buildability, and designs that extend structural lifetimes and enable reuse of components, could deliver comparable human wellbeing with dramatically less new material. Scenario analyses published in Nature Communications in 2021 estimated that material-efficiency strategies in residential buildings alone could save billions of tonnes of resources and significant emissions, and the new global inventory provides the granular baseline needed to identify where those strategies would pay off most.

The technical achievement of characterizing 606 million buildings also matters for how cities are managed. Material stocks are not static; they are slow-motion flows. Every year, part of the stock is demolished and replaced, releasing construction and demolition waste, while new construction draws fresh resources from mines, quarries and forests. Knowing where materials are concentrated, how old they are and what they are made of allows planners to treat the existing city as a reservoir, an urban mine whose steel and concrete can be recovered and reused rather than discarded. It also enables more accurate life-cycle assessment, better forecasts of future demolition waste, and more precise carbon accounting, since the emissions embedded in a city’s buildings can now be estimated structure by structure rather than guessed from national averages.

The study builds on a rapid recent evolution in the field. A 2025 analysis in the Journal of Industrial Ecology produced the first global high-resolution map of building material stocks, and a 2024 study in Engineering used big geodata to reveal spatial patterns of built-environment stocks across and within fifty Chinese cities, showing that material intensity varies not only between countries but dramatically between neighbourhoods of the same city. The new Nature Cities work scales this building-level approach to the entire planet and adds the explicit inequality framing, quantifying the gap between the material abundance of wealthy urban systems and the material scarcity of poorer ones. In doing so, it connects two research communities that have often worked separately: industrial ecologists tracking global resource flows, and urban scientists studying the shape and growth of cities.

The implications reach into international climate negotiations, development finance and urban planning practice alike. For high-income countries, the findings suggest that the priority is not merely reducing new construction but managing an already massive stock efficiently, through renovation, densification, adaptive reuse and circular-economy strategies that keep existing materials in service. For low-income and middle-income countries, the findings argue for infrastructure and housing policies that leapfrog the most material-wasteful development patterns, adopting compact urban forms and efficient construction technologies before car-dependent sprawl and resource-hungry building standards become locked in. The 835 gigatonnes already in the ground cannot be un-built, but the next several hundred tonnes that humanity will inevitably add remain, for now, a choice. The new global inventory of the world’s buildings makes that choice visible, measurable and, for the first time, mappable at the scale of every structure on Earth.

Subject of Research: Global building-level quantification of urban material stocks and inequality

Article Title: Global characterization of building-level weight reveals urban material inequality

Article References: Global characterization of building-level weight reveals urban material inequality. (2026). Nature Cities. https://doi.org/10.1038/s44284-026-00509-w

Image Credits: AI Generated

DOI: 10.1038/s44284-026-00509-w

Keywords: material stocks, built environment, urban inequality, buildings, concrete, material efficiency, urban form, sustainability, cities, resource use, Global, characterization

The study established a framework for understanding urban soil pollution, pointing to how soil can act as both a sink for pollutants and a source of problematics for urban dwellers. Soils are not just passive layers beneath our feet; they interact dynamically with air, water, and living organisms, making them critical to both urban ecosystems and human health. Contaminated soils can lead to the leaching of toxic substances into groundwater, affecting not only environmental quality but also human health directly through food systems and exposure pathways.

Researchers identified several potentially toxic elements (PTEs) of concern, including lead, arsenic, and cadmium, which are often found in urban soils due to industrial activities, vehicle emissions, and improper waste disposal. The cumulative consequences of these elements accumulate not just in soil but permeate the very air and water systems that urban populations depend upon. Such pollution raises questions about regulatory oversight and the implementation of more stringent environmental protection measures.

Alongside PTEs, the presence of polycyclic aromatic hydrocarbons (PAHs) in urban soils marks a significant environmental hazard. These organic compounds, resulting from incomplete combustion of organic material, are notorious for their mutagenic and carcinogenic properties. The urban environment serves as an incubator for these compounds, with common culprits including vehicular emissions, industrial discharges, and even residential heating methods. As their prevalence grows, so too does the need for effective management strategies to mitigate their impact on human health and local ecosystems.

Microplastics have emerged as another critical concern in urban soil studies. The infiltration of plastic particles into soil has escalated with the exponential increase in plastic use and poor waste management practices. These microplastics not only physically alter soil composition but also affect microbial communities, which are vital for nutrient cycling and overall soil health. The review by Çayır et al. highlighted a disconcerting trend: urban soils are becoming increasingly laden with these pervasive pollutants, reflecting broader environmental patterns globally.

Moreover, the review notes the disparities between urban regions within Türkiye, with larger cities like Istanbul and Ankara showing higher concentrations of pollutants compared to less populated areas. This urban-rural divide underscores the nuanced nature of pollution; while larger populations create greater emissions, smaller towns may lack the infrastructure for effective waste management, leading to localized environmental crises.

The findings also resonate with the broader climatological context, drawing attention to how climate change can exacerbate existing soil pollution problems. Increased rainfall and flooding can mobilize contaminants, spreading them over wider areas and threatening water quality. The researchers argued for a synergistic approach to urban planning, where environmental considerations are woven into the fabric of city management and development practices.

Interdisciplinary collaboration is vital to addressing the urban soil crisis. Environmental scientists, urban planners, policy makers, and public health experts must come together to forge cohesive strategies that target pollution at its source. The importance of public awareness cannot be understated; a well-informed citizenry can advocate for change and hold local governments accountable for environmental stewardship.

The review’s conclusions serve as a clarion call for robust policy interventions aimed at preserving urban soil health. Effective soil management strategies, pollution control regulations, and community engagement initiatives can significantly mitigate the current trajectory of urban soil degradation. Integrated management systems that incorporate green infrastructure, sustainable practices, and soil remediation technologies can pave the way for healthier urban environments.

Importantly, the study highlights the role of education in fostering a culture of environmental responsibility and sustainable practices. By investing in soil science education and promoting simple actions that can reduce pollution, stakeholders can create a more informed public that values and protects their local environment.

Finally, as cities in Türkiye stand on the cusp of further development, the insights offered by Çayır et al. not only chart a path for immediate action but also call for a reimagining of what urban landscapes can be. The benefits of investing in clean soil ecosystems extend beyond environmental health, promising better quality of life, increased biodiversity, and sustainable urban growth that harmonizes with nature.

As the world grapples with the implications of urbanization, Türkiye’s challenge and response to urban soil pollution serve as a microcosm of broader global environmental issues. It is imperative that the lessons drawn from this review propel urgently needed changes towards sustainable urban environments. The future of urban living undoubtedly hinges on our ability to manage our soil resources wisely, equipping cities to thrive in harmony with their natural surroundings.

Subject of Research: Urban soil pollution in Türkiye.

Article Title: Urban soil pollution in Türkiye: a review of potentially toxic elements, polycyclic aromatic hydrocarbons, and microplastics in major cities.

Article References: Çayır, G., Rouhani, A., Al Souki, K.S. et al. Urban soil pollution in Türkiye: a review of potentially toxic elements, polycyclic aromatic hydrocarbons, and microplastics in major cities. Environ Monit Assess 197, 1366 (2025). https://doi.org/10.1007/s10661-025-14834-5

Image Credits: AI Generated

DOI: https://doi.org/10.1007/s10661-025-14834-5

Keywords: Urbanization, soil pollution, potentially toxic elements, polycyclic aromatic hydrocarbons, microplastics, Türkiye, environmental health, sustainable urban development.

Nick Haddad, a prominent figure in the realm of ecology, has been recognized for his substantial contributions to conservation science. His work is particularly focused on enhancing biodiversity and formulating strategies to protect vulnerable species, notably butterflies, which are essential to Michigan’s ecosystems. Haddad’s research investigates the interplay between wildlife and their habitats, emphasizing the importance of habitat corridors that facilitate animal movement and survival in the face of urban and agricultural development. The implications of his studies extend beyond Michigan, potentially influencing biodiversity conservation practices globally. His insight into the phenomena of decreasing butterfly populations underscores the urgent need for ecological intervention and sustainable land-use planning.

Gemma Reguera, whose pioneering efforts in environmental microbiology have garnered her recognition as a fellow, focuses on the incredible capabilities of bacteria in remediating pollutants and cleaning up contaminated environments. Reguera’s research takes a closer look at how specific microbial flora can be harnessed to mitigate the effects of pollutants, particularly in relation to radioactive waste and other hazardous materials. Her contributions shed light on the symbiotic relationship between humans and microbes, advocating for the integration of microbiological solutions in environmental policies and cleanup efforts. As climate change and industrialization intensify the environmental crisis, Reguera’s work represents a beacon of hope in the quest for sustainable solutions.

In the realm of health sciences, Laura McCabe has made remarkable strides in understanding the relationship between gut health and bone density. With osteoporosis affecting over 40 million individuals in the United States alone, McCabe’s research addresses a pressing public health issue. Through her investigations, she has unveiled the complex mechanisms through which gut microbiota interact with bone metabolism, particularly in contexts of menopause and certain diseases. McCabe’s work advocates for the gut as a therapeutic target for combating osteoporosis, paving the way for innovative treatment strategies that leverage the intricate links between diet, microbiome, and bone health. Her assertion that gut health can significantly influence bone density could revolutionize approaches to osteoporosis treatment and prevention.

Michael Thoennessen, an eminent figure in nuclear physics, has played a crucial role in advancing our understanding of atomic nuclei and their behavior. His contributions include research that elucidates the properties of neutron-rich isotopes, which are vital for both theoretical and practical applications in nuclear science. Thoennessen’s leadership at the National Superconducting Cyclotron Laboratory has provided invaluable research opportunities for young scientists in the field. His ongoing engagement with the Facility for Rare Isotope Beams not only enhances MSU’s academic stature but also supports a collaborative environment that pushes the boundaries of current scientific knowledge. The recognition he received from AAAS reflects his lasting impact on both his field and the next generation of researchers.

The honors received by Haddad, Reguera, McCabe, and Thoennessen illustrate MSU’s commitment to fostering scientific excellence and addressing the pressing challenges facing society today. This initiative aligns with MSU President Kevin M. Guskiewicz’s vision of promoting research that not only contributes to academic knowledge but also tangibly benefits communities, thereby shaping future knowledge leaders and innovative thinkers. Each of these researchers exemplifies the values of inquiry, resilience, and service that are fundamental to the mission of MSU.

As the American Association for the Advancement of Science continues to celebrate scientific achievements through such recognitions, it underscores the importance of sustained investment in science and engineering. The exemplary work of this cohort of fellows reaffirms the significance of interdisciplinary collaboration in tackling global challenges ranging from environmental conservation to public health. In a world increasingly besieged by uncertainty and change, the contributions of scientists like those from MSU herald a hopeful narrative for the future of scientific inquiry and its application for social good.

The scientific pursuits of these researchers do not exist in a vacuum; they resonate globally, reflecting an urgent call for informed decision-making in policy and practice. As their work progresses, it is essential that their findings reach broader audiences, informing public discourse and influencing policies that ensure a sustainable and healthful future for all. The recognition by the AAAS serves not only as an accolade but as an impetus for further exploration—reminding all scholars of the immense responsibility that comes with scientific discovery and innovation.

The ongoing achievements of these Michigan State University researchers exemplify a model of academic excellence that resonates across disciplines and communities. Their stories are reminders of the power of individual endeavors in propelling collective progress. As they continue their research, the implications of their work will undoubtedly extend beyond academic confines, reaching individuals and societies deeply affected by the challenges they seek to address.

Ultimately, the distinction of being named AAAS fellows is not solely an acknowledgment of past achievements; it denotes a commitment to future endeavors aimed at bettering human existence. The work of Haddad, Reguera, McCabe, and Thoennessen is a testament to the potential of scientific inquiry to inspire change, foster understanding, and cultivate a healthier planet.

Subject of Research: Conservation science, Environmental microbiology, Gut health and bone density, Nuclear physics.

Article Title: Michigan State University Researchers Recognized as AAAS Fellows: A Testament to Scientific Excellence.

News Publication Date: March 27, 2024.

Web References: MSUToday.

References: Not applicable.

Image Credits: Not applicable.

Keywords: Michigan State University, AAAS fellows, ecology, microbiology, osteoporosis, nuclear physics, environmental science, biodiversity, scientific recognition.