CoChat
Sign Up
Cited by 105CO2 Sequestration and Geologic InteractionsSoil Carbon and Nitrogen DynamicsSoil and Environmental Studies

Rapid Removal of Atmospheric CO2 by Urban Soils

Open access
Washbourne, Carla-Leanne, Lopez-Capel, Elisa, Renforth, Phil, Ascough, Philippa L., Manning, David A. C.·2015·Environmental Science & Technology
DOI 10.1021/es505476d
Open this paper in CoChat — free accountOpen PDF

Abstract

The measured calcium carbonate content of soils to a depth of 100 mm at a large urban development site has increased over 18 months at a rate that corresponds to the sequestration of 85 t of CO2/ha (8.5 kg of CO2 m–2) annually. This is a consequence of rapid weathering of calcium silicate and hydroxide minerals derived from the demolition of concrete structures, which releases Ca that combines with CO2 ultimately derived from the atmosphere, precipitating as calcite. Stable isotope data confirm an atmospheric origin for carbonate carbon, and 14C dating indicates the predominance of modern carbon in the pedogenic calcite. Trial pits show that carbonation extends to depths of ≥1 m. Work at other sites shows that the occurrence of pedogenic carbonates is widespread in artificially created urban soils containing Ca and Mg silicate minerals. Appropriate management of fewer than 12000 ha of urban land to maximize calcite precipitation has the potential to remove 1 million t of CO2 from the atmosphere annually. The maximal global potential is estimated to be approximately 700–1200 Mt of CO2 per year (representing 2.0–3.7% of total emissions from fossil fuel combustion) based on current rates of production of industry-derived Ca- and Mg-bearing materials.

AI snapshot

Written from the paper’s full text.

TL;DR

At a 10 ha urban redevelopment site, soil CaCO₃ content to 100 mm increased over 18 months, equivalent to 85 t CO₂/ha (8.5 kg CO₂ m⁻²) sequestered annually via weathering of demolition-derived calcium silicates/hydroxides and precipitation of calcite. Stable and radiogenic isotopes indicate modern atmospheric carbon, and the authors estimate management of fewer than 12,000 ha of UK urban soils could remove 1 Mt CO₂/year, with global potential of 700–1200 Mt CO₂/year.

Key findings

  • Surface soil (0–100 mm) CaCO₃ increased from 22.0 to 39.0 wt% over 18 months; soil inorganic C stock to 100 mm rose from 44 to 79 t C/ha; the estimated precipitation rate was 192 t CaCO₃/ha annually, equivalent to 85 t CO₂/ha (8.5 kg CO₂ m⁻²) annually or 23 t C/ha annually.
  • Stable isotope data (δ¹⁸O −10.0 to −13.8‰; δ¹³C −6.5 to −14.6‰ V-PDB) and ¹⁴C measurements (30.4 ± 0.1% and 80.7 ± 0.4% modern carbon in two samples) confirm an atmospheric/modern origin; mixing suggests a mean of 50% hydroxylation-derived carbonate. Trial pits show carbonation to depths ≥1 m, with average 15.9 ± 9.7 wt% CaCO₃ for approximately 0–3 m.
  • Weathering of artificial silicates showed 20% SiO₂ loss, equivalent to 10⁻¹²·⁷ mol Si cm⁻² s⁻¹ or 16,000 t Si km⁻² a⁻¹, two orders of magnitude faster than the greatest natural catchment weathering rates.
  • Management of fewer than 12,000 ha of urban land could remove 1 Mt CO₂ annually; global potential is estimated at approximately 700–1200 Mt CO₂/year (2.0–3.7% of fossil fuel combustion emissions) based on current production rates of industry-derived Ca- and Mg-bearing materials.

Methods

  • Newcastle Science Central, a 10 ha urban development site with demolition-derived made ground. Surface samples were collected at 72 points on September 16, 2010, and 23 of these were resampled on March 13, 2012, located to 25 mm accuracy by GPS; samples were 0–100 mm depth, 0.5–1.0 kg, sieved to <2 mm on-site, then air-dried, crushed, and sieved to <63 μm. Seven trial pits were excavated to up to 3 m and sampled at approximately 0.5 m intervals.
  • Bulk carbonate was determined for 95 samples (72 in 2010, 23 in 2012) using an Eijkelkamp calcimeter (BS 7755-3.10:1995); inorganic C was determined by Leco CS-244; stable C/O isotopes were measured for 18 samples by IRMS; ¹⁴C was measured on two 2010 samples by AMS; XRF was conducted on 14 samples, XRD on 4, and TG-DSC-QMS on 6.
  • Statistical comparison used Shapiro-Wilk and Wilcoxon Signed Rank Test (significance 0.000) to test the CaCO₃ increase between sampling dates.

Limitations

  • Stated: the starting CaCO₃ composition is not known but assumed small and non-zero; portlandite content was not quantified; the observed rate is likely to change with time, but post-2012 changes could not be measured because of construction activity; extrapolation to 0.5 m assumes a mean CaCO₃ content of 20 ± 12.3 wt% and that 50% of carbonate is newly formed; the global estimate is based on current production rates of industry-derived Ca- and Mg-bearing materials.
  • Stated: Science Central is a single 10 ha site, though described as typical of modern development practice; observed variability is attributed to heterogeneous material composition and site-specific properties such as drainage.
  • Evident from the text: only 23 surface points were resampled and only two samples were ¹⁴C-dated; the isotope mixing end-members and the 50% hydroxylation proportion are model assumptions; no direct CO₂ flux measurement is reported.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1021/es505476d

Cites

46 of 46 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 41 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    14C dating indicates a predominance of modern carbon in the pedogenic calcite at Science Central.

    “Stable isotope data confirm an atmospheric origin for carbonate carbon, and 14 C dating indicates the predominance of modern carbon in the pedogenic calcite.”
    Quote in the paperSubstantial claim
  • Findingown data

    At Science Central, the measured calcium carbonate content of soils to 100 mm depth increased over 18 months at a rate corresponding to sequestration of 85 t CO2/ha (8.5 kg CO2 m-2) annually.

    “The measured calcium carbonate content of soils to a depth of 100 mm at a large urban development site has increased over 18 months at a rate that corresponds to the sequestration of 85 t of CO 2 /ha (8.5 kg of CO 2 m -2 ) annually.”
    Quote in the paperSubstantial claim
  • Findingown data

    Overall, the CaCO3 content to 100 mm depth over 18 months (2010-2012) increases from 22.0 to 39.0 wt%.

    “Overall, the CaCO 3 content to 100 mm depth over 18 months (2010-2012) increases from 22.0 to 39.0 wt %.”
    Quote in the paperSubstantial claim
  • Findingown data

    14C measurements suggest that a significant proportion of the C present in carbonates originates from the modern atmosphere (i.e., nonlithogenic sources).

    “14 C measurements (two samples selected from the extremes of the observed range of the δ 13 C data) suggest that a significant proportion of the C present in carbonates originates from the modern atmosphere (i.e., nonlithogenic sources).”
    Quote in the paperSubstantial claim
  • Findingown data

    The rate of increase inferred from the observed change at Science Central exceeds estimates for soil carbon increases in rural land use [e.g., 3.63 t of C ha-1 year-1 through establishment of new woodlands].

    “The rate of increase inferred from the observed change at Science Central exceeds estimates for soil carbon increases in rural land use [e.g., 3.63 t of C ha -1 year -1 (0.363 kg of C m -2 year -1 ) through establishment (for example) of new woodlands].36”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [36] Cantarello, 2011, Potential effects of future land-use change on regional carbon stocks in the UK, Environ. Sci. Policy source

      Not checked in the free run.

  • The quote only partly states this claim. 2
  • May combine two claims. 23
  • Classified as probably not a substantial claim. 12

  • The quote only partly states this claim.

    Findingown data

    Stable isotope data confirm an atmospheric origin for carbonate carbon at Science Central.

    “Stable isotope data confirm an atmospheric origin for carbonate carbon, and 14 C dating indicates the predominance of modern carbon in the pedogenic calcite.”
    Quote in the paperSubstantial claim

  • The quote only partly states this claim.

    Findingown data

    Trial pits show that carbonation extends to depths of at least 1 m at Science Central.

    “Trial pits show that carbonation extends to depths of ≥1 m.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    TG-DSC-QMS and XRD analysis confirm the presence of calcite as the dominant calcium carbonate mineral and demonstrate the presence of portlandite.

    “Thermogravimetry-differential scanning calorimetry coupled with quadrupole mass spectrometry (TG-DSC-QMS) and Xray diffraction (XRD) analysis (Figures S1 and S2 of the Supporting Information) confirm the presence of calcite as the dominant calcium carbonate mineral and demonstrate the presence of portlandite [Ca(OH) 2 ].”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingcitation

    The measured silicate weathering rate is several orders of magnitude slower than dissolution rates for hydrated cement minerals determined through laboratory experiments but is 2 orders of magnitude faster than the greatest weathering rates for natural catchments.

    “This is several orders of magnitude slower than dissolution rates for hydrated cement minerals determined through laboratory experiments (10 -8.0 mol of Ca cm -2 s -1 ) 17 but is 2 orders of magnitude faster than the greatest weathering rates for natural catchments (e.g., a global average of 24 t km -2 year -1 , 33 or 100s t km -2 year -1 for tropical volcanic arcs).39,40”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [17] Washbourne, 2012, Investigating carbonate formation in urban soils as a method for capture and storage of atmospheric carbon, Sci. Total Environ. source

      Not checked in the free run.

    • cites [33] Macleod, 1991, The mechanism of carbonate growth on concrete structures, as elucidated by carbon and oxygen isotope analyses, Chem. Geol.

      Not checked in the free run.

    • cites [39] Gaillardet, 1999, Global silicate weathering and CO2 consumption rates deduced from the chemistry of large rivers, Chem. Geol. source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Trial pit samples to approximately 1 m depth have CaCO3 contents varying from 0.0 to 97.3 wt%, with an average value of 19.1 wt% excluding a single outlier.

    “Trial pit samples to approximately 1 m depth have CaCO 3 contents varying from 0.0 to 97.3 wt %, with an average value of 19.1 wt % excluding a single outlier (97.3 wt % CaCO 3 ), which likely corresponds to inclusion of limestone aggregate (Figure 2A; variability with depth is due to changes in ground conditions).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    The observed loss of 20% of the SiO2 content is equivalent to a weathering rate of 10^-12.7 mol of Si cm-2 s-1 or 16000 t of Si km-2 a-1.

    “The observed loss of 20% of the SiO 2 content is equivalent to a weathering rate of 10 -12.7 mol of Si cm -2 s -1 (normalized to a nominal mineral surface area of 1 m 2 g -1 , conservatively estimated from particle size distribution 17 and assuming 1 Mt of material on-site 22 ) or 16000 t of Si km -2 a -1 (when normalized to the site area).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [17] Washbourne, 2012, Investigating carbonate formation in urban soils as a method for capture and storage of atmospheric carbon, Sci. Total Environ. source

      Not checked in the free run.

    • cites [22] Newcastle Science Central. www.newcastlesciencecentral.com).

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    The range of the entire sample data is 5.3-43.0 wt% CaCO3 in 2010 and 26.5-61.4 wt% CaCO3 in 2012.

    “The range of the entire sample data is 5.3-43.0wt % CaCO 3 in 2010 and for the repeat samples 26.5-61.4wt % CaCO 3 in 2012.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The measured soil inorganic carbon stock to 100 mm depth increased from 44 to 79 t of C ha-1 in 18 months, approaching values similar to those reported for organic carbon in arable land [84 t of C ha-1].

    “The measured soil inorganic carbon stock to 100 mm depth increased from 44 to 79 t of C ha -1 (0.0044-0.0079 t of C m -2 ) in 18 months, approaching values similar to those reported for organic carbon in arable land [84 t of C ha -1 (0.0085 t of C m -2 )].35”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [35] Smith, 2000, Revised estimates of the carbon mitigation potential of UK agricultural land, Soil Use Manage. source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Leco analysis reported an average inorganic carbon content of 4.1 ± 1.2 wt%, corresponding to a CaCO3 concentration of 38.9 ± 15.6 wt%.

    “Leco analysis reported an average inorganic carbon content of 4.1 ± 1.2 wt % (range, 3.0-7.1 wt %; SEM, ±0.48 wt %), corresponding to a CaCO 3 concentration of 38.9 ± 15.6 wt % (range, 25.2-59.1 wt %; equivalent analytical precision, ±4.0 wt %).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Between the two sampling dates, the mean δ13C values change from -9.9 to -12.6‰ and δ18O from -10.7 to -12.6‰.

    “Between the two sampling dates, the mean δ 13 C values change from -9.9 to -12.6‰ and δ 18 O from -10.7 to -12.6‰.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    A value of 30.4 ± 0.1% Modern Carbon was found for a sample with a δ13C of -3.13‰ (B15) and 80.7 ± 0.4% Modern Carbon for a sample with a δ13C of -13.55‰ (J11).

    “A value of 30.4 ± 0.1% Modern Carbon was found for a sample with a δ 13 C of -3.13‰ (B15) and 80.7 ± 0.4% Modern Carbon for a sample with a δ 13 C of -13.55‰ (J11; points are indicated in Figure 3).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    CaCO3 content does not vary with depth in a consistent manner across the site; trial pit data generally show little variation with depth to ≥1.5 m.

    “CaCO 3 content does not vary with depth in a consistent manner across the site; nevertheless, the trial pit data generally show little variation with depth to ≥1.5 m.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Study design and conductown data

    The 2010 and 2012 surface soil samples were collected from the same locations with high precision (within 25 mm) using GPS.

    “Surface soils (0-100 mm) were sampled systematically on two occasions 18 months apart, with very precise location (within 25 mm).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Study design and conductreasoning

    The observed rate of carbon capture at Science Central may change with time, and changes at the site could not be measured after 2012 because of construction activity.

    “It is likely that the observed rate will change with time, but it is not possible to measure changes at the site since 2012 because of more recent construction activity.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Limited information is available for the formation of pedogenic carbonates in U.K. soils.

    “Limited information is available for the formation of pedogenic carbonates in U.K. soils, with Rawlins 10 estimating the total inorganic carbon stock of soil (0-30 cm depth) to be 186 Mt of C, around 5.5% of the estimated total soil carbon stock (organic and inorganic) across the U.K.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [10] Rawlins, 2011, The importance of inorganic carbon in soil carbon databases and stock estimates: A case study from England, Soil Use Manage. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    Management of urban soils constitutes a promising and relatively inexpensive process for removing CO2 from the atmosphere.

    “The results of this study suggest that the management of urban soils constitutes a promising and relatively inexpensive process for removing CO 2 from the atmosphere.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    On the basis of mixing between lithogenic and pedogenic carbonate formed at high pH, proportions of each component vary from 42 to 80% lithogenic and from 58 to 20% hydroxylation (mean hydroxylation of 50%).

    “Thus, on the basis of mixing between lithogenic and pedogenic carbonate formed at high pH, proportions of each component vary from 42 to 80% lithogenic and from 58 to 20% hydroxylation (mean hydroxylation of 50%).”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The mixing line for stable isotopes assumes a lithogenic end member δ18O of -0.0‰ and δ13C of -0.0‰, and a hydroxylation end member δ18O of -20.5‰ (assuming meteoric water δ18O of -7.8‰ vs SMOW) and δ13C of -25.3‰.
    • The authors state this as an assumption: Photosynthetic inputs to newly formed soil carbonate at Science Central are negligible.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Similar observations have been found at other sites, where the rate of CO2 removal has been estimated on the basis of the assumption that calcium carbonate content in soil was zero at the time of demolition or soil formation.

    “Similar observations have been found at other sites, where the rate of CO 2 removal has been estimated on the basis of the assumption that calcium carbonate content in soil was zero at the time of demolition 9 or soil formation.14”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [9] Renforth, 2009, Carbonate precipitation in artificial soils as a sink for atmospheric carbon dioxide, Appl. Geochem. source

      Not checked in the free run.

    • cites [14] Manning, 2013, Carbonate precipitation in artificial soils produced from basaltic quarry fines and composts: An opportunity for passive carbon sequestration, Int. J. Greenhouse Gas Control source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductown data

    The extrapolation to 0.5 m depth in Figure 4 is based on trial pit data showing consistent CaCO3 contents to that depth.

    “Figure 4 summarizes CO 2 removal, extrapolating to 0.5 m depth on the basis of the consistent CaCO 3 contents to that depth from trial pit samples (see Figure 2A)”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The contemporary mean CaCO3 content used for extrapolation is 20 ± 12.3 wt%.
    • The authors state this as an assumption: The proportion of carbonate newly formed through hydroxylation is 50% overall.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    The portlandite content of hydrated cement is typically around 15% (∼5% in concrete).

    “The portlandite content of the samples was not quantified but is typically around 15% in hydrated cement (∼5% in concrete).37”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [37] Scrivener, 2004, Quantitative study of Portland cement hydration by X-ray diffraction/Rietveld analysis and independent methods, Cem. Concr. Res. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    Enhanced SiO2 removal is consistent with the high pH of this anthropogenic soil and may explain the elevated weathering rate measured from rivers draining urbanized catchments.

    “Enhanced SiO 2 removal is consistent with the high pH of this anthropogenic soil and may explain the elevated weathering rate measured from rivers draining urbanized catchments.41”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [41] Moosdorf, 2011, Atmospheric CO2 consumption by chemical weathering in North America, Geochim. Cosmochim. Acta source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Precipitation of carbonate minerals as a consequence of silicate weathering contributes to stabilization of atmospheric CO2 over geological time periods and to formation of pedogenic carbonates in natural and artificial soils over shorter time scales.

    “The precipitation of carbonate minerals as a consequence of silicate weathering contributes to the stabilization of atmospheric CO 2 over geological time periods 4,7 and also contributes to the formation of pedogenic carbonates in both natural 8 and artificial soils 9 over much shorter time scales.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [4] Berner, 1983, The carbonate-silicate geochemical cycle and its effect on atmospheric carbon dioxide over the past 100 million years, Am. J. Sci. source

      Not checked in the free run.

    • cites [7] Berner, 2001, GEOCARB III: A revised model of atmospheric CO2 over Phanerozoic time, Am. J. Sci. source

      Not checked in the free run.

    • cites [8] Nettleton, 1991 source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    The data in Figure 3 represent mixtures of CaCO3 derived from geological (lithogenic) sources and carbonate that originates from hydroxylation of CO2 at high pH, forming a linear plot representing mixing between lithogenic and pedogenic carbonates.

    “The data shown in Figure 3 represent mixtures of CaCO 3 derived from geological (lithogenic) sources (such as limestone aggregate in construction materials) and carbonate that originates from hydroxylation of CO 2 at high pH, 9 forming a linear plot representing mixing between lithogenic and pedogenic carbonates.9”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [9] Renforth, 2009, Carbonate precipitation in artificial soils as a sink for atmospheric carbon dioxide, Appl. Geochem. source

      Not checked in the free run.

    • The authors state this as an assumption: The mixing line for stable isotopes assumes a lithogenic end member δ18O of -0.0‰ and δ13C of -0.0‰, and a hydroxylation end member δ18O of -20.5‰ (assuming meteoric water δ18O of -7.8‰ vs SMOW) and δ13C of -25.3‰.
    • The authors state this as an assumption: Photosynthetic inputs to newly formed soil carbonate at Science Central are negligible.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    Calcimeter and Leco analysis give closely corresponding soil CaCO3 contents.

    “Two methods of determination, calcimeter and Leco analysis (total carbon-organic carbon), give closely corresponding soil CaCO 3 contents.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Hydroxylation occurs at high pH (>11.5), in environments corresponding to those dominated by weathering of artificial minerals in construction materials, as at Science Central.

    “Hydroxylation occurs at high pH (>11.5), 26 in environments corresponding to those dominated by the weathering of artificial minerals in construction materials, as at Science Central.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [26] Dietzel, 1992, Chemical and 13C/12C- and 18O/16O-isotope evolution of alkaline drainage waters and the precipitation of calcite, Appl. Geochem. source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationcitation

    Carbonation appears to decrease with depth, likely due to isolation of materials from the atmosphere; therefore, management that increases atmospheric exposure is likely to increase carbonation rates throughout the site.

    “Carbonation appears to decrease with depth, likely due to the isolation of materials from the atmosphere; therefore, management that increases atmospheric exposure (e.g., through appropriate planting that takes CO 2 to depth via plant root systems and associated metabolism) is likely to increase carbonation rates throughout the site.14,45,46”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [14] Manning, 2013, Carbonate precipitation in artificial soils produced from basaltic quarry fines and composts: An opportunity for passive carbon sequestration, Int. J. Greenhouse Gas Control source

      Not checked in the free run.

    • cites [45] Wilson, 2014, Offsetting of CO2 emissions by air capture in mine tailings at the Mount Keith Nickel Mine, Western Australia: Rates, controls and prospects for carbon neutral mining, Int. J. Greenhouse Gas Control source

      Not checked in the free run.

    • cites [46] Power, 2014, Strategizing carbon-neutral mines: A case for pilot projects, Minerals source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based). May combine two claims.

    Interpretationnone given

    Science Central represents a single 10 ha site but is typical of modern development practice that involves on-site crushing of materials and the retention of crusher fines on-site as part of the soil.

    “Science Central represents a single 10 ha site but is typical of modern development practice that involves on-site crushing of materials and the retention of crusher “fines” on-site as part of the soil.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable).

    Interpretationcitation

    Globally, appropriate management of land as part of the development or reconstruction of sites where concrete structures have been demolished or destroyed should be considered as a way of partly compensating for emissions associated with the loss of CO2 from firing carbonate raw materials (around 50% of the total CO2 emissions of a kiln).

    “Globally, appropriate management of land as part of the development or reconstruction of sites where concrete structures have been demolished or destroyed should be considered as a way of partly compensating for emissions associated with the loss of CO 2 from firing carbonate raw materials (around 50% of the total CO 2 emissions of a kiln).48”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [48] Van Oss, 2003, Cement Manufacture and the Environment. Part II: Environmental Challenges and Opportunities, J. Ind. Ecol. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Approximately 3 × 10^9 t of cement is produced annually, emitting approximately 1.5 × 10^9 t of CO2 from chemical decarbonation.

    “Approximately 3 × 10 9 t of cement is produced annually, emitting approximately 1.5 × 10 9 t of CO 2 from chemical decarbonation.49”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [49] Renforth, 2011, Silicate production and availability for mineral carbonation, Environ. Sci. Technol. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationnone given

    In the long term, a proportion of the calcite may dissolve, contributing to bicarbonate in groundwater and surface water.

    “In the long term, a proportion of the calcite may dissolve, contributing to bicarbonate in groundwater and surface water (fluxes similar to those from outcropping natural carbonate-cemented sandstones).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    Given the average building lifespan is around 50 years, this material could become available by midcentury, representing a substantial carbon capture opportunity for the industry.

    “Given the average building lifespan is around 50 years, this material could become available by midcentury, representing a substantial carbon capture opportunity for the industry.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Calcite precipitation has also been observed in artificial soils prepared by blending natural calcium silicate rocks with compost.

    “Although reported here for urban soils with artificial mineral inputs, calcite precipitation has also been observed in artificial soils prepared by blending natural calcium silicate rocks with compost.14”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [14] Manning, 2013, Carbonate precipitation in artificial soils produced from basaltic quarry fines and composts: An opportunity for passive carbon sequestration, Int. J. Greenhouse Gas Control source

      Not checked in the free run.

32 of 32

  • The authors state this as an assumption.

    The starting CaCO3 composition of the material at Science Central is small but non-zero.

    “The starting composition of the material with respect to CaCO 3 is not known but can be assumed to be small (but non-zero) because of the possible inclusion of limestone aggregate or concrete carbonation occurring over the life of the now demolished structures.”

  • The authors state this as an assumption.

    The mixing line for stable isotopes assumes a lithogenic end member δ18O of -0.0‰ and δ13C of -0.0‰, and a hydroxylation end member δ18O of -20.5‰ (assuming meteoric water δ18O of -7.8‰ vs SMOW) and δ13C of -25.3‰.

    “A mixing line is superimposed on the data, 17 which assumes a lithogenic end member value for δ 18 O of -0.0‰, a δ 13 C of -0.0‰, and a hydroxylation (high-pH) end member δ 18 O of -20.5‰ (assuming a meteoric water δ 18 O of -7.8‰ vs SMOW) and a δ 13 C of -25.3‰ 9,17,26,28,30,31”

  • The authors state this as an assumption.

    Photosynthetic inputs to newly formed soil carbonate at Science Central are negligible.

    “As the soils investigated in this study have little plant cover, and the observed range of δ 18 O and δ 13 C extends to more negative values, it is assumed that photosynthetic inputs to newly formed soil carbonate are negligible.”

  • The authors state this as an assumption.

    The contemporary mean CaCO3 content used for extrapolation is 20 ± 12.3 wt%.

    “assuming a contemporary mean CaCO 3 content of 20 ± 12.3 wt % (mean CaCO 3 content from trial pits to 0.5 m and surface samples of 19.5 wt %)”

  • The authors state this as an assumption.

    The proportion of carbonate newly formed through hydroxylation is 50% overall.

    “assuming that the proportion of carbonate newly formed (shortly prior to or since demolition) through hydroxylation is 50% overall.”

  • The authors state this as an assumption.

    Ti is immobile during weathering.

    “once normalized to TiO 2 (assuming Ti to be immobile during weathering), 38”
6 of 6

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Some wastes containing more reactive minerals are sufficiently reactive to passively draw down CO2 from ambient air, as evidenced by mine tailings and demolition wastes.

    “In fact, some wastes containing more reactive minerals are sufficiently reactive to passively draw down CO2 from the ambient air, as evidenced by mine tailings [8,9] and demolition wastes [10].”

    From Carbon Mineralization with North American PGM Mine Tailings—Characterization and Reactivity Analysis (2021) · cites this paper as [10]

  • Although chemically similar to basalt, artificial calcium-rich silicates contain minerals that dissolve several orders of magnitude faster, react rapidly with CO2 in soils under ambient conditions, and are produced in fine particle sizes that facilitate accelerated weathering.

    “Although chemically similar to basalt, these artificial calcium-rich silicates contain minerals that dissolve several orders of magnitude faster, react rapidly with CO2 in soils under ambient conditions 40 , and are produced in fine particle sizes that facilitate accelerated weathering 41 .”

    From Potential for large-scale CO2 removal via enhanced rock weathering with croplands (2020) · cites this paper as [40]

  • SSP2 potentially represents the largest material production pathway, as other SSPs forecast lower consumption or economic growth producing 30-50% less material globally.

    “SSP2 potentially represents the largest material production pathway, as other SSPs forecast lower consumption or economic growth producing 30-50% less material globally.”

    From Potential for large-scale CO2 removal via enhanced rock weathering with croplands (2020) · cites this paper as [40]

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

Each contradiction between two passages listed here was confirmed by an independent check.

  • Radiocarbon sample falls outside the stated δ13C range

    Minor

    The reported δ13C value of −3.13‰ for sample B15 is outside the stated range of −6.5 to −14.6‰ for the site's samples.

1 of 1

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Related

Authors
Washbourne, C.-L., Lopez-Capel, E., Renforth, P., Ascough, P. L., & Manning, D. A. C.
Affiliations
  • Newcastle University (GB)
  • Newcastle University , , ,
  • Cardiff University (GB)
  • Scottish Universities Environmental Research Centre (GB)
Corresponding author
Manning, David A. C.
ORCID
Venue
Environmental Science & Technology
Publisher
American Chemical Society (ACS)
Published
2015-04-02
Volume
49
Issue
9
Pages
5434-5440
ISSN
  • 0013-936X (ISSN-L)
  • 1520-5851
DOI
10.1021/es505476d
OpenAlex
W2069685370
Semantic Scholar
50006f2a21e5e61d911253525a2f0e0133b9a06d
Cited by
105
References
46
Citations by year
2026: 6 · 2025: 8 · 2024: 11 · 2023: 12 · 2022: 17 · 2021: 15 · 2020: 12 · 2019: 12 · 2018: 3 · 2017: 7 · 2016: 2
FWCI
2.88
Type
journal article
Language
en
Open access
Licence
Locations
  • Environmental Science & Technology (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • ORCA Online Research @Cardiff (Cardiff University) (acceptedVersion)
  • ENLIGHTEN (Jurnal Bimbingan dan Konseling Islam) (acceptedVersion)
  • UCL Discovery (University College London) (submittedVersion)
Funders
  • Engineering and Physical Sciences Research Council (EP/I002154/1, EP/K034952/1)
  • Natural Environment Research Council (NA)
Topics
  • Physical Sciences › Environmental Science › Environmental Engineering › CO2 Sequestration and Geologic Interactions
  • Life Sciences › Agricultural and Biological Sciences › Soil Science › Soil Carbon and Nitrogen Dynamics
  • Life Sciences › Agricultural and Biological Sciences › Soil Science › Soil and Environmental Studies
Keywords
urban soils, CO2 sequestration, calcite precipitation, pedogenic carbonates, calcium carbonate, demolition waste, atmospheric CO2 removal, stable carbon isotopes, radiocarbon dating, carbonation, urban land management, fossil fuel emissions
MeSH terms
Atmosphere, Calcium Carbonate, Carbon Dioxide, Carbon Radioisotopes, Cities, England, Fossil Fuels, Minerals, Soil, Calcium Compounds, Silicates, Carbon Sequestration

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-10.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-10.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review