Closing the geologic carbon cycle.

Estimates of sedimentary organic carbon burial fluxes based on inventory and isotope mass balance methods have been divergent. A new calculation of the isotope mass balance using a revised assessment of the inputs to the ocean-atmosphere system resolves the apparent discrepancy. Inputs include weathering of carbonate and old kerogen, geogenic methane oxidation, and volcanic and metamorphic degassing. Volcanic and metamorphic degassing comprise ≈23% of the total C input. Inputs from isotopically light OCpetro and CH4-geo drive the mean δ13C of the input to =-8.0 ± 1.9‰, notably lower than the commonly assumed volcanic degassing value. The isotope mass balance model yields a modern burial flux =15.9 ± 6.6 Tmol y-1. The impact of the mid-Miocene Climatic Optimum isotope anomaly is an integrated excess deposition ≈ 4.3 × 106 Tmol between 18 and 11 Ma, which is both longer and larger than estimates for the total degassing by the Columbia River Basalt eruptions, implying a complex carbon system response to large eruptive events. Monte Carlo evaluation finds that late Cenozoic net growth of the carbonate reservoir is very likely while net growth of the Corg reservoir is less certain but more likely than not. At present, subduction does not appear to keep up with net sedimentation and the overall masses of sedimentary carbonate and organic carbon are likely increasing. Growth in the sedimentary Corg reservoir implies oxidation of the surface environment and likely increases in atmospheric pO2.

Enhanced weathering in the US Corn Belt delivers carbon removal with agronomic benefits.

Terrestrial enhanced weathering (EW) of silicate rocks, such as crushed basalt, on farmlands is a promising scalable atmospheric carbon dioxide removal (CDR) strategy that urgently requires performance assessment with commercial farming practices. We report findings from a large-scale replicated EW field trial across a typical maize-soybean rotation on an experimental farm in the heart of the United Sates Corn Belt over 4 y (2016 to 2020). We show an average combined loss of major cations (Ca2+ and Mg2+) from crushed basalt applied each fall over 4 y (50 t ha-1 y-1) gave a conservative time-integrated cumulative CDR potential of 10.5 ± 3.8 t CO2 ha-1. Maize and soybean yields increased significantly (P < 0.05) by 12 to 16% with EW following improved soil fertility, decreased soil acidification, and upregulation of root nutrient transport genes. Yield enhancements with EW were achieved with significantly (P < 0.05) increased key micro- and macronutrient concentrations (including potassium, magnesium, manganese, phosphorus, and zinc), thus improving or maintaining crop nutritional status. We observed no significant increase in the content of trace metals in grains of maize or soybean or soil exchangeable pools relative to controls. Our findings suggest that widespread adoption of EW across farming sectors has the potential to contribute significantly to net-zero greenhouse gas emissions goals while simultaneously improving food and soil security.

Lithium isotopic evidence for enhanced reverse weathering during the Early Triassic warm period.

Elevated temperatures persisted for an anomalously protracted interval following pulsed volcanic carbon release associated with the end-Permian mass extinction, deviating from the expected timescale of climate recovery following a carbon injection event. Here, we present evidence for enhanced reverse weathering-a CO2 source-following the end-Permian mass extinction based on the lithium isotopic composition of marine shales and cherts. We find that the average lithium isotopic composition of Lower Triassic marine shales is significantly elevated relative to that of all other previously measured Phanerozoic marine shales. Notably, the record generated here conflicts with carbonate-based interpretations of the lithium isotopic composition of Early Triassic seawater, forcing a re-evaluation of the existing framework used to interpret lithium isotopes in sedimentary archives. Using a stochastic forward lithium cycle model, we demonstrate that elevated reverse weathering is required to reproduce the lithium isotopic values and trends observed in Lower Triassic marine shales and cherts. Collectively, this work provides direct geochemical evidence for enhanced reverse weathering in the aftermath of Earth's most severe mass extinction.

Climate forcing controls on carbon terrestrial fluxes during shale weathering.

Climate influences near-surface biogeochemical processes and thereby determines the partitioning of carbon dioxide (CO2) in shale, and yet the controls on carbon (C) weathering fluxes remain poorly constrained. Using a dataset that characterizes biogeochemical responses to climate forcing in shale regolith, we implement a numerical model that describes the effects of water infiltration events, gas exchange, and temperature fluctuations on soil respiration and mineral weathering at a seasonal timescale. Our modeling approach allows us to quantitatively disentangle the controls of transient climate forcing and biogeochemical mechanisms on C partitioning. We find that ~3% of soil CO2 (1.02 mol C/m2/y) is exported to the subsurface during large infiltration events. Here, net atmospheric CO2 drawdown primarily occurs during spring snowmelt, governs the aqueous C exports (61%), and exceeds the CO2 flux generated by pyrite and petrogenic organic matter oxidation (~0.2 mol C/m2/y). We show that shale CO2 consumption results from the temporal coupling between soil microbial respiration and carbonate weathering. This coupling is driven by the impacts of hydrologic fluctuations on fresh organic matter availability and CO2 transport to the weathering front. Diffusion-limited transport of gases under transient hydrological conditions exerts an important control on CO2(g) egress patterns and thus must be considered when inferring soil CO2 drawdown from the gas phase composition. Our findings emphasize the importance of seasonal climate forcing in shaping the net contribution of shale weathering to terrestrial C fluxes and suggest that warmer conditions could reduce the potential for shale weathering to act as a CO2 sink.

High rates of rock organic carbon oxidation sustained as Andean sediment transits the Amazon foreland-floodplain.

The oxidation of organic carbon contained within sedimentary rocks ("petrogenic" carbon, or hereafter OCpetro) emits nearly as much CO2 as is released by volcanism, thereby playing a key role in the long-term global C budget. High erosion rates in mountains have been shown to increase OCpetro oxidation. However, these settings also export unweathered material that may continue to react in downstream floodplains. The relative importance of OCpetro oxidation in mountains versus floodplains remains difficult to assess as disparate methods have been used in the different environments. Here, we investigate the sources and fluxes of rhenium (Re) in the Rio Madre de Dios to quantify OCpetro oxidation from the Andes to the Amazon floodplain using a common approach. Dissolved rhenium concentrations (n = 131) range from 0.01 to 63 pmol L-1 and vary depending on lithology and geomorphic setting. We find that >75% of the dissolved Re derives from OCpetro oxidation and that this proportion increases downstream. We estimate that in the Andes, OCpetro oxidation releases 11.2+4.5/-2.8 tC km-2 y-1 of CO2, which corresponds to ~41% of the total OCpetro denudation (sum of oxidized and solid OCpetro). A Re mass balance across the Rio Madre de Dios shows that 46% of OCpetro oxidation takes place in the Andes, 14% in the foreland-lowlands, and 40% in the Andean-fed floodplains. This doubling of OCpetro oxidation flux downstream of the Andes demonstrates that, when present, floodplains can greatly increase OCpetro oxidation and CO2 release.

The rise of New Guinea and the fall of Neogene global temperatures.

The ~2,000-km-long Central Range of New Guinea is a hotspot of modern carbon sequestration due to the chemical weathering of igneous rocks with steep topography in the warm wet tropics. These high mountains formed in a collision between the Australian plate and ophiolite-bearing volcanic arc terranes, but poor resolution of the uplift and exhumation history has precluded assessments of the impact on global climate change. Here, we develop a palinspastic reconstruction of the Central Range orogen with existing surface geological constraints and seismic data to generate time-temperature paths and estimate volumes of eroded material. New (U-Th)/He thermochronology data reveal rapid uplift and regional denudation between 10 and 6 Mya. Erosion fluxes from the palinspastic reconstruction, calibrated for time with the thermochronological data, were used as input to a coupled global climate and weathering model. This model estimates 0.6 to 1.2 °C of cooling associated with the Late Miocene rise of New Guinea due to increased silicate weathering alone, and this CO2 sink continues to the present. Our data and modeling experiments support the hypothesis that tropical arc-continent collision and the rise of New Guinea contributed to Neogene cooling due to increased silicate weathering.

Exploring the synergy of enhanced weathering and Bacillus subtilis: A promising strategy for sustainable agriculture.

Climate change is one of the most urgent environmental challenges that humanity faces. In addition to the reduction of greenhouse gas emissions, safe and robust carbon dioxide removal (CDR) technologies that capture atmospheric CO2 and ensure long-term sequestration are required. Among CDR technologies, enhanced silicate weathering (ESW) has been suggested as a promising option. While ESW has been demonstrated to depend strongly on pH, water, and temperature, recent studies suggest that biota may accelerate mineral weathering rates. Bacillus subtilis is a plant growth-promoting rhizobacterium that can facilitate weathering to obtain mineral nutrients. It is a promising agricultural biofertilizer, as it helps plants acquire nutrients and protects them from environmental stresses. Given that croplands are optimal implementation fields for ESW, any synergy between ESW and B. subtilis can hold great potential for further practice. B. subtilis was reported to enhance weathering under laboratory conditions, but there is a lack of data for soil applications. In a soil-mesocosm experiment, we examined the effect of B. subtilis on basalt weathering. B. subtilis-basalt interaction stimulated basalt weathering and increased soil extractable Fe. The combined application displayed higher CDR potential compared to basalt-only application (3.7 vs. 2.3 tons CO2 ha-1) taking solid and liquid cation pools into account. However, the cumulative CO2 efflux decreased by approximately 2 tons CO2 ha-1 with basalt-only treatment, while the combined application did not affect the CO2 efflux. We found limited mobilization of cations to the liquid phase as most were retained in the soil. Additionally, we found substantial mobilization of basalt-originated Mg, Fe, and Al to oxide- and organic-bound soil fractions. We, therefore, conclude that basalt addition showed relatively low inorganic CDR potential but a high capacity for SOM stabilization. The outcomes indicated the importance of weathering rate-GHG emission integration and the high potential of SOM stabilization in ESW studies.

Enhanced rock weathering increased soil phosphorus availability and altered root phosphorus-acquisition strategies.

Enhanced rock weathering (ERW) has been proposed as a measure to enhance the carbon (C)-sequestration potential and fertility of soils. The effects of this practice on the soil phosphorus (P) pools and the general mechanisms affecting microbial P cycling, as well as plant P uptake are not well understood. Here, the impact of ERW on soil P availability and microbial P cycling functional groups and root P-acquisition traits were explored through a 2-year wollastonite field addition experiment in a tropical rubber plantation. The results show that ERW significantly increased soil microbial carbon-use efficiency and total P concentrations and indirectly increased soil P availability by enhancing organic P mobilization and mineralization of rhizosheath carboxylates and phosphatase, respectively. Also, ERW stimulated the activities of P-solubilizing (gcd, ppa and ppx) and mineralizing enzymes (phoADN and phnAPHLFXIM), thus contributing to the inorganic P solubilization and organic P mineralization. Accompanying the increase in soil P availability, the P-acquisition strategy of the rubber fine roots changed from do-it-yourself acquisition by roots to dependence on mycorrhizal collaboration and the release of root exudates. In addition, the direct effects of ERW on root P-acquisition traits (such as root diameter, specific root length, and mycorrhizal colonization rate) may also be related to changes in the pattern of belowground carbon investments in plants. Our study provides a new insight that ERW increases carbon-sequestration potential and P availability in tropical forests and profoundly affects belowground plant resource-use strategies.

Stabilisation of soil organic matter with rock dust partially counteracted by plants.

Soil application of Ca- and Mg-rich silicates can capture and store atmospheric carbon dioxide as inorganic carbon but could also have the potential to stabilise soil organic matter (SOM). Synergies between these two processes have not been investigated. Here, we apply finely ground silicate rock mining residues (basalt and granite blend) to a loamy sand in a pot trial at a rate of 4% (equivalent to 50 t ha-1 ) and investigate the effects of a wheat plant and two watering regimes on soil carbon sequestration over the course of 6 months. Rock dust addition increased soil pH, electric conductivity, inorganic carbon content and soil-exchangeable Ca and Mg contents, as expected for weathering. However, it decreased exchangeable levels of micronutrients Mn and Zn, likely related to the elevated soil pH. Importantly, it increased mineral-associated organic matter by 22% due to the supply of secondary minerals and associated sites for SOM sorption. Additionally, in the nonplanted treatments, rock supply of Ca and Mg increased soil microaggregation that subsequently stabilised labile particulate organic matter as organic matter occluded in aggregates by 46%. Plants, however, reduced soil-exchangeable Mg and Ca contents and hence counteracted the silicate rock effect on microaggregates and carbon within. We suggest this cation loss might be attributed to plant exudates released to solubilise micronutrients and hence neutralise plant deficiencies. The effect of enhanced silicate rock weathering on SOM stabilisation could substantially boost its carbon sequestration potential.

Enhanced silicate weathering accelerates forest carbon sequestration by stimulating the soil mineral carbon pump.

Enhanced silicate rock weathering (ERW) is an emerging strategy for carbon dioxide removal (CDR) from the atmosphere to mitigate anthropogenic climate change. ERW aims at promoting soil inorganic carbon sequestration by accelerating geochemical weathering processes. Theoretically, ERW may also impact soil organic carbon (SOC), the largest carbon pool in terrestrial ecosystems, but experimental evidence for this is largely lacking. Here, we conducted a 2-year field experiment in tropical rubber plantations in the southeast of China to evaluate the effects of wollastonite powder additions (0, 0.25, and 0.5 kg m-2) on both soil organic and inorganic carbon at 0-10 cm depth. We found that ERW significantly increased the concentration of SOC and HCO3 -, but the increases in SOC were four and eight times higher than that of HCO3 - with low- and high-level wollastonite applications. ERW had positive effects on the accrual of organic carbon in mineral-associated organic matter (MAOM) and macroaggregate fractions, but not on particulate organic matter. Path analysis suggested that ERW increased MAOM mainly by increasing the release of Ca, Si, and Fe, and to a lesser extent by stimulating root growth and microbial-derived carbon inputs. Our study indicates that ERW with wollastonite can promote SOC sequestration in stable MOAM in surface soils through both the soil mineral carbon pump and microbial carbon pump. These effects may have been larger than the inorganic CDR during our experiment. We argue it is essential to account for the responses of SOC in the assessments of CDR by ERW.

Social determinants of health and obstetric outcomes: A report and recommendations of the workshop of the Society for Maternal-Fetal Medicine.

This article is a report of a 2-day workshop, entitled "Social determinants of health and obstetric outcomes," held during the Society for Maternal-Fetal Medicine 2022 Annual Pregnancy Meeting. Participants' fields of expertise included obstetrics, pediatrics, epidemiology, health services, health equity, community-based research, and systems biology. The Commonwealth Foundation and the Alliance of Innovation on Maternal Health cosponsored the workshop and the Society for Women's Health Research provided additional support. The workshop included presentations and small group discussions, and its goals were to accomplish the following.

Racial/ethnic disparities in chronic wounds: Perspectives on linking upstream factors to health outcomes.

This review explores the complex relationship between social determinants of health and the biology of chronic wounds associated with diabetes mellitus, with an emphasis on racial/ethnic disparities. Chronic wounds pose significant healthcare challenges, often leading to severe complications for millions of people in the United States, and disproportionally affect African American, Hispanic, and Native American individuals. Social determinants of health, including economic stability, access to healthcare, education, and environmental conditions, likely influence stress, weathering, and nutrition, collectively shaping vulnerability to chronic diseases, such as obesity and DM, and an elevated risk of chronic wounds and subsequent lower extremity amputations. Here, we review these issues and discuss the urgent need for further research focusing on understanding the mechanisms underlying racial/ethnic disparities in chronic wounds, particularly social deprivation, weathering, and nutrition, to inform interventions to address these disparities.

Prioritizing Non-Carbon Dioxide Removal Mitigation Strategies Could Reduce the Negative Impacts Associated with Large-Scale Reliance on Negative Emissions.

Carbon dioxide removal (CDR) is necessary for reaching net zero emissions, with studies showing potential deployment at multi-GtCO2 scale by 2050. However, excessive reliance on future CDR entails serious risks, including delayed emissions cuts, lock-in of fossil infrastructure, and threats to sustainability from increased resource competition. This study highlights an alternative pathway─prioritizing near-term non-CDR mitigation and minimizing CDR dependence. We impose a 1 GtCO2 limit on global novel CDR deployment by 2050, forcing aggressive early emissions reductions compared to 8-22 GtCO2 in higher CDR scenarios. Our results reveal that this low CDR pathway significantly decreases fossil fuel use, greenhouse gas (GHG) emissions, and air pollutants compared to higher CDR pathways. Driving rapid energy transitions eases pressures on land (including food cropland), water, and fertilizer resources required for energy and negative emissions. However, these sustainability gains come with higher mitigation costs from greater near-term low/zero-carbon technology deployment for decarbonization. Overall, this work provides strong evidence for maximizing non-CDR strategies such as renewables, electrification, carbon neutral/negative fuels, and efficiency now rather than betting on uncertain future CDR scaling. Ambitious near-term mitigation in this decade is essential to prevent lock-in and offer the best chance of successful deep decarbonization. Our constrained CDR scenario offers a robust pathway to achieving net zero emissions with limited sustainability impacts.

Enhanced Rock Weathering for Carbon Removal-Monitoring and Mitigating Potential Environmental Impacts on Agricultural Land.

Terrestrial enhanced rock weathering (ERW) is the application of pulverized silicate rock to soils for the purposes of carbon removal and improved soil health. Although a geochemical modeling framework for ERW in soils is emerging, there is a scarcity of experimental and field trial data exploring potential environmental impacts, risks, and monitoring strategies associated with this practice. This paper identifies potential negative consequences and positive cobenefits of ERW scale-up and suggests mitigation and monitoring strategies. To do so, we examined literature on not only ERW but also industry, agriculture, ecosystem science, water chemistry, and human health. From this work, we develop recommendations for future research, infrastructure, and policy needs. We also recommend target metrics, risk mitigation strategies, and best practices for monitoring that will permit early detection and prevention of negative environmental impacts.

Iron Chelation in Soil: Scalable Biotechnology for Accelerating Carbon Dioxide Removal by Enhanced Rock Weathering.

Enhanced rock weathering (EW) is an emerging atmospheric carbon dioxide removal (CDR) strategy being scaled up by the commercial sector. Here, we combine multiomics analyses of belowground microbiomes, laboratory-based dissolution studies, and incubation investigations of soils from field EW trials to build the case for manipulating iron chelators in soil to increase EW efficiency and lower costs. Microbial siderophores are high-affinity, highly selective iron (Fe) chelators that enhance the uptake of Fe from soil minerals into cells. Applying RNA-seq metatranscriptomics and shotgun metagenomics to soils and basalt grains from EW field trials revealed that microbial communities on basalt grains significantly upregulate siderophore biosynthesis gene expression relative to microbiomes of the surrounding soil. Separate in vitro laboratory incubation studies showed that micromolar solutions of siderophores and high-affinity synthetic chelator (ethylenediamine-N,N'-bis-2-hydroxyphenylacetic acid, EDDHA) accelerate EW to increase CDR rates. Building on these findings, we develop a potential biotechnology pathway for accelerating EW using the synthetic Fe-chelator EDDHA that is commonly used in agronomy to alleviate the Fe deficiency in high pH soils. Incubation of EW field trial soils with potassium-EDDHA solutions increased potential CDR rates by up to 2.5-fold by promoting the abiotic dissolution of basalt and upregulating microbial siderophore production to further accelerate weathering reactions. Moreover, EDDHA may alleviate potential Fe limitation of crops due to rising soil pH with EW over time. Initial cost-benefit analysis suggests potassium-EDDHA could lower EW-CDR costs by up to U.S. $77 t CO2 ha-1 to improve EW's competitiveness relative to other CDR strategies.

Tracking Dynamic Chemical Reactivity Networks with High-Resolution Mass Spectrometry: A Case of Microplastic-Derived Dissolved Organic Carbon.

Chemical degradation testing often involves monitoring the loss of a chemical or the evolution of a single diagnostic product through time. Here, we demonstrate a novel approach to tracing complex degradation networks using mass-spectrometry-based methods and open cheminformatics tools. Ester- and ether-based thermoplastic polyurethane (TPU_Ester and TPU_Ether) microplastics (350 µm) and microplastics-derived dissolved organic carbon (MP-DOC) were photoweathered in a simulated marine environment and subsequently analyzed by liquid chromatography coupled to high-resolution mass spectrometry. We formula-annotated 1342 and 2344 unique features in the MP-DOC of TPU_Ester and TPU_Ether, respectively. From these, we extracted 199 and 568 plausible parent-transformation product pairs via matching of features (a) with complementary increasing and decreasing trends (Spearman's correlation coefficient between normalized intensity and time), (b) spectral similarities of at least three accurate mass MS2 fragments, and (c) at least 3 ppm agreement between the theoretical and measured change in m/z between the parent-transformation product formula. Molecular network analysis revealed that both chain scission and cross-linking reactions occur dynamically rather than degradation proceeding in a monotonic progression to smaller or more oxygenated structures. Network nodes with the highest degree of centrality were tentatively identified using in silico fragmentation and can be prioritized for toxicity screening or other physicochemical properties of interest. This work has important implications for chemical transformation tracking in complex mixtures and may someday enable improved elucidation of environmental transformation rules (i.e., structure-reactivity relationships) and fate modeling.

The Mining Industry's Role in Enhanced Weathering and Mineralization for CO2 Removal.

Enhanced weathering and mineralization (EWM) aim to remove carbon dioxide (CO2) from the atmosphere by accelerating the reaction of this greenhouse gas with alkaline minerals. This suite of geochemical negative emissions technologies has the potential to achieve CO2 removal rates of >1 gigatonne per year, yet will require gigatonnes of suitable rock. As a supplier of rock powder, the mining industry will be at the epicenter of the global implementation of EWM. Certain alkaline mine wastes sequester CO2 under conventional mining conditions, which should be quantified across the industry. Furthermore, mines are ideal locations for testing acceleration strategies since tailings impoundments are contained and highly monitored. While some environmentally benign mine wastes may be repurposed for off-site use─reducing costs and risks associated with their storage─numerous new mines will be needed to supply rock powders to reach the gigatonne scale. Large-scale EWM pilots with mining companies are required to progress technology readiness, including carbon verification approaches. With its knowledge of geological formations and ore processing, the mining industry can play an essential role in extracting the most reactive rocks with the greatest CO2 removal capacities, creating supply chains, and participating in life-cycle assessments. The motivations for mining companies to develop EWM include reputational benefits and carbon offsets needed to achieve carbon neutrality.

Enhanced Nesquehonite Formation and Stability in the Presence of Dissolved Silica.

One possible carbon dioxide sequestration strategy is via the carbonation of dissolved Mg2+ obtained through olivine ((Mg,Fe)2SiO4) dissolution. However, silica is also produced during the breakdown of olivine. This component may have a detrimental effect on the yield of Mg-carbonate as Mg2+ incorporation into complex Mg silicate phases would limit CO2 uptake by this system. Yet this potential competition is currently not considered. Here, we use crystal growth experiments at temperatures applicable for potential coastal applications to test the effect of silica on the formation of the hydrated Mg-carbonate phase nesquehonite (MgCO3·3H2O). Solution chemistry analysis coupled with phase identification demonstrates that the presence of silica in the solution can actually assist the formation of nesquehonite and increase its yield by as much as 60 times. Our findings suggest that the presence of silica changes interfacial stabilities, lowering the energetic barrier for nesquehonite nucleation. In addition, in situ attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) transformation experiments demonstrated that nesquehonite precipitating in a solution containing a high concentration of dissolved silica exhibits enhanced stability against its transformation into hydromagnesite. These findings will help to better constrain what we expect for applications of olivine during carbon remediation strategies as well as assist yields for industrial applications that use Mg-based cement as building materials to facilitate a CO2-neutral or negative footprint.

Forecasting Photo-Dissolution for Future Oil Spills at Sea: Effects of Oil Properties and Composition.

Photo-dissolution, the photochemical production of water-soluble species from oil, can transfer oil-derived dissolved organic carbon (DOC) from floating surface slicks to the underlying seawater. Photo-dissolution was likely a quantitatively relevant fate process for the Macondo crude oil spilled during the 2010 Deepwater Horizon spill, but the importance of photo-dissolution for other oils is poorly constrained. This study evaluated the photo-dissolution reactivities (apparent quantum yields) and modeled rates for oils with diverse physical properties and chemical compositions, including an ultra low sulfur fuel oil (ULSFO). Photo-dissolution from UV (310 nm) light was strongly positively correlated with the fraction of small, gas-oil range compounds (

Anthropogenic effects on soils in the eastern Tibetan Plateau revealed by geochemical elemental characteristics.

The Tibetan Plateau (TP) constitutes a fragile and sensitive ecological environment, which is vulnerable to global climate change and human activities. To investigate the anthropogenic effects on the TP's environmental system is valuable for guiding human responses and adaptations to future environmental changes. In this study, we detailedly analyzed the geochemical elements of four representative soil sections developed on loess from Ganzi, Jinchuan, Aba, and Chuanzhusi in the eastern TP. The chemical elemental profiles distinctly indicated the presence of typical anthropogenic elements (Cu, Zn, Ni, Cr, Pb, Mn, and Fe), underscoring the substantial influence of human activities on TP soil, and showing spatial variance. Our results indicate that anthropogenic impacts were relatively low at Aba and Ganzi, resulting in a deficit of anthropogenic elements at the surface layer. Whereas at Jinchuan and Chuanzhusi, relatively intense anthropogenic impacts have led to the enrichment of anthropogenic elements in the topsoil. We infer that agricultural activities, increased traffic, and expansion of tourism activities were the major factors affecting the anthropogenic elements of TP soils. Our study highlights the impact of human activities on soil geochemical processes in the Tibetan Plateau.