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Cited by 700CO2 Sequestration and Geologic InteractionsCarbon Dioxide Capture TechnologiesClimate Change and Geoengineering

Potential for large-scale CO2 removal via enhanced rock weathering with croplands

Open access
Beerling, David J., Kantzas, Euripides P., Lomas, Mark R., Wade, Peter, Eufrasio, Rafael M., Renforth, Phil, Sarkar, Binoy, Andrews, M. Grace +13 more·2020·Nature
DOI 10.1038/s41586-020-2448-9
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Abstract

Enhanced silicate rock weathering (ERW), deployable with croplands, has potential use for atmospheric carbon dioxide (CO 2) removal (CDR), which is now necessary to mitigate anthropogenic climate change 1. ERW also has possible co-benefits for improved food and soil security, and reduced ocean acidification 2-4. Here we use an integrated performance modelling approach to make an initial techno-economic assessment for 2050, quantifying how CDR potential and costs vary among nations in relation to business-as-usual energy policies and policies consistent with limiting future warming to 2 degrees Celsius 5. China, India, the USA and Brazil have great potential to help achieve average global CDR goals of 0.5 to 2 gigatonnes of carbon dioxide (CO 2) per year with extraction costs of approximately US$80-180 per tonne of CO 2. These goals and costs are robust, regardless of future energy policies. Deployment within existing croplands offers opportunities to align agriculture and climate policy. However, success will depend upon overcoming political and social inertia to develop regulatory and incentive frameworks. We discuss the challenges and opportunities of ERW deployment, including the potential for excess industrial silicate materials (basalt mine overburden, concrete, and iron and steel slag) to obviate the need for new mining, as well as uncertainties in soil weathering rates and land-ocean transfer of weathered products.

AI snapshot

Written from the paper’s full text.

TL;DR

Enhanced silicate rock weathering (ERW) on existing croplands could remove 0.5–2 Gt CO₂ yr⁻¹ by 2050, with China, India, the USA and Brazil having the largest potential. Estimated extraction costs of ~$80–180 t⁻¹ CO₂ are robust across business-as-usual and 2°C energy scenarios, but deployment depends on policy, social acceptance and field validation.

Key findings

  • ERW could contribute 0.5–2 Gt CO₂ yr⁻¹ globally by 2050; aggregate CDR of 25–100 Gt CO₂ over five decades would save up to 10% of the remaining ~900 Gt CO₂ budget for limiting warming to below 2°C.
  • The top three ranked countries for CDR potential are China, USA and India; Indonesia and Brazil also have relatively high potential due to extensive agricultural lands and suitable climates, while European countries have an order-of-magnitude lower potential than China, USA and India.
  • Costs vary by nation: USA $160–180 t⁻¹ CO₂, Canada and European nations $160–190 t⁻¹ CO₂, and China, India, Mexico, Indonesia and Brazil $55–120 t⁻¹ CO₂. A carbon price of $100–150 t⁻¹ CO₂ would cover most ERW costs for key nations.
  • ERW could augment 2030 NDCs by ~5–10% for China and the USA, 40% for India, and 100% of Brazil’s pledged 2030 CO₂ emissions plus some fraction of other countries’ emissions; France and Spain up to ~40%, and Poland, Italy and Germany ~10%.

Methods

  • Integrated performance model with sub-national detail for major economies (USA, India, China, Brazil, Europe, plus Indonesia, Canada, Mexico), using a 1-D vertical reactive transport model with steady-state flow and a rock-grain dissolution source term.
  • Baseline application rate of 40 t ha⁻¹ yr⁻¹; two basalt types (fast- and slow-weathering) and two log-normal particle size distributions; optimization of p80 for maximum net CDR; Monte Carlo sampling (n ≈ 100) for fractal-dimension uncertainty; BAU and 2°C energy scenarios for 2050.
  • Cost assessment includes mining, processing, distribution/transport and spreading, using GIS origin-destination rail/road network analysis and country-specific diesel, labour and electricity costs; silicate waste production forecast using SSP2 GDP projections.

Limitations

  • Stated: uncertainties in baseline application rate and basalt mineralogy; extrapolation of laboratory weathering rates to field scale; surface passivation not treated in detail; need for long-term field-scale ERW trials; potential trapping of weathered cations on ion exchange surfaces or in secondary minerals; poorly constrained duration of carbon sequestration and possible CO₂ sink saturation; possible CO₂ degassing in large river systems not considered; no account of wider impacts of ERW supply chains on other markets; recycling penetration for steel not considered beyond current rate.
  • Stated: success depends on overcoming political and social inertia, developing regulatory and incentive frameworks, and wider public acceptance.
  • Evident from the text: the analysis is a techno-economic modelling assessment, not field-validated; the performance model does not explicitly account for secondary clay minerals, which the authors note makes it conservative with respect to basalt dissolution.

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

Integrity signals

Registry

Crossref · 10.1038/s41586-020-2448-9

Cites

81 of 81 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 121 cited sources checked · 0 supported · 0 flagged

  • Findingown data
    § The potential for large-scale CO 2 removal via rock weathering on croplands

    Extraction costs for China, India, the United States and Brazil are ~$80-180 t -1 CO2.

    “China, India, the United States and Brazil have large potential to help achieve average global CDR targets of 0.5 to 2 Gt CO2 yr -1 with extraction costs of ~$80-180 t -1 CO2.”
    Quote in the paperSubstantial claim
  • Findingown data
    § The potential for large-scale CO 2 removal via rock weathering on croplands

    China, India, the United States and Brazil have large potential to help achieve average global CDR targets of 0.5 to 2 Gt CO2 yr -1.

    “China, India, the United States and Brazil have large potential to help achieve average global CDR targets of 0.5 to 2 Gt CO2 yr -1 with extraction costs of ~$80-180 t -1 CO2.”
    Quote in the paperSubstantial claim
  • Findingcitation

    The three top ranked countries with the highest CDR potential are coincidentally the highest fossil fuel CO2 emitters (China, USA and India).

    “Overall, we find the three top ranked countries with the highest CDR potential are coincidentally the highest fossil fuel CO2 emitters (China, USA and India) 6 (Figure 1).”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [6] Le Quéré, C. et al. Global carbon budget 2018. Earth Syst. Sci. Data 10, 2141–2194 (2018).

      Not checked in the free run.

  • Findingown data

    In Europe, ERW could aid significant decarbonisation of France and Spain (up to approximately 40%).

    “In Europe, ERW could aid significant decarbonisation of France and Spain (up to approximately 40%), and to a lesser extent Poland, Italy and Germany (all ~10%) (Figure 2).”
    Quote in the paperSubstantial claim
  • Findingcitation

    ERW has a similar potential to that of other CDR strategies estimated for 2050, including BECCS (0.5-5 Gt CO2 yr -1), DAC (0.5-5), biochar (0.5-2), SOC (0.5-5), and afforestation/reforestation (0.5-3.6).

    “In the context of our CDR targets, ERW has a similar potential to that of other CDR strategies 23 estimated for 2050, including bio-energy with carbon capture and storage (BECCS), widely adopted in IPCC future scenarios (0.5-5 Gt CO2 yr -1 ), direct air carbon capture and storage (DAC) (0.5-5 Gt CO2 yr -1 ), biochar (0.5 to 2 Gt CO2 yr -1 ), soil organic carbon (SOC) sequestration (0.5-5 Gt CO2 yr”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [23] Fuss, S. et al. Negative emissions—Part 2: Costs, potentials and side effects. Environ. Res. Lett. 13, 063002 (2018). source

      Not checked in the free run.

  • May combine two claims. 59
  • Classified as probably not a substantial claim. 34
  • The quote only partly states this claim. 3

  • May combine two claims.

    Findingreasoning

    National median CO2 removal curves typically show CDR capacity rising with increasing cropland area, with carbon removal by silicate soil amendment reaching a plateau or declining in the case of Canada.

    “National median CO2 removal curves typically show CDR capacity rising with increasing cropland area, with carbon removal by silicate soil amendment reaching a plateau or declining in the case of Canada (Figure 1).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Brazil may be able to offset 100% of its pledged 2030 CO2 emissions plus some fraction of those from other countries through ERW.

    “For India, the gain rises to 40% of its current pledged emissions, and Brazil may be able to offset 100% of its pledged 2030 CO2 emissions plus some fraction of those from other countries (Figure 2).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    European countries have an order-of-magnitude lower CDR potential than China, USA, and India, mainly because of lower agricultural land area.

    “European countries have an order-of-magnitude lower CDR potential than China, USA, and India, mainly because of lower agricultural land area.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    Indonesia and Brazil, with CO2 emissions 10-20 times lower than the USA and China, have relatively high CDR potential due to extensive agricultural lands and climates suitable for high silicate rock weathering efficiency.

    “Indonesia and Brazil, with CO2 emissions 10-20 times lower than the USA and China, have relatively high CDR potential due to extensive agricultural lands and climates suitable for high silicate rock weathering efficiency.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    India's total energy production falls by ~40% with a transition to low carbon energy production in the 2°C scenario, lowering energy available for grinding basalt, and thus the potential for increased CDR by ERW.

    “This contrasts with results for India, whose total energy production falls by ~40% with a transition to low carbon energy production in the 2 o C scenario, lowering energy available for grinding basalt, and thus the potential for increased CDR by ERW.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Within our scenarios, the demand for basalt required for ERW rises with an increasing CDR target and scales with agricultural land area.

    “Within our scenarios, the demand for basalt required for ERW rises with an increasing CDR target and scales with agricultural land area (Table 1).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    Using ERW cost as a guide, the per capita annual cost of achieving zero net emissions would be highest for Canada ($3004), the USA ($2780), China ($832) and EU28 nations ($1288).

    “ERW cannot offset all fossil fuel emissions, but using its cost as a guide, the per capita annual cost of achieving zero net emissions, a goal for decarbonisation, would be highest for Canada ($3004), the USA ($2780), China ($832) and EU28 nations ($1288).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingcitation

    Our estimated ERW costs of carbon removal for nations are comparable to estimates summarized for BECCS ($100-200 t-1 CO2), DAC ($100-300 t-1 CO2), and biochar ($30-$120 t-1 CO2), but higher than estimates for SOC sequestration ($0-10 t-1 CO2).

    “Our estimated ERW costs of carbon removal for nations are comparable to estimates summarized for BECCS ($100 to 200 t -1 CO2), DAC ($100-300 t -1 CO2), and biochar ($30-$120 t -1 CO2), but higher than estimates for SOC sequestration ($0-10 t -1 CO2) 23 .”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [23] Fuss, S. et al. Negative emissions—Part 2: Costs, potentials and side effects. Environ. Res. Lett. 13, 063002 (2018). source

      Not checked in the free run.

  • May combine two claims.

    Findingown data

    Bulk silicate production, linked to the construction and demolition sector, is modelled to increase substantially in all four nations, with China and India having combined production by 2060 of ~13 Gt yr-1.

    “Bulk silicate production, linked to the construction and demolition sector, is modelled to increase substantially in all four nations, with China and India having combined production by 2060 of ~13 Gt yr -1 (Figure 4).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Our cost estimates based on current prices fall within the range of prior ERW assessments ($75-250 tCO2-1) while resolving differences among nations.

    “Our cost estimates based on current prices fall within the range of prior ERW assessments ($75-250 tCO2 -1 ) [21][22][23] while resolving differences among nations (Figure 3; Table 1; SI figs.S16-S25; SI tables S13-S14).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [21][22][23]

      Not checked in the free run.

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

    Findingnone given

    ERW has potential for ancillary benefits by limiting coastal zone acidification and improving food and soil security.

    “with potential for ancillary benefits by limiting coastal zone acidification and improving food and soil security”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    Basaltic minerals undergo dissolution at different rates, with some minerals continuing to undergo dissolution and capture CO2 after the first year of application.

    “Basaltic minerals undergo dissolution at different rates, with some minerals continuing to undergo dissolution and capture CO2 after the first year of application.”
    • Also stated in: § Extended · plain
      “Basaltic minerals undergo dissolution at different rates, with some minerals continuing to undergo dissolution and capture CO2 after the first year of application.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    Carbon emissions per unit mass of ground rock depend on particle size, the CO2 emissions per kilowatt-hour of electricity generated from component energy sources, and the carbon costs of sourcing and transporting the silicate materials.

    “Carbon emissions per unit mass of ground rock depend on particle size (Extended Data Fig. 10), the CO2 emissions per kilowatt-hour of electricity generated from component energy sources (fossil fuels, nuclear and renewables), as well as the carbon costs of sourcing and transporting the silicate materials.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingnone given

    Grinding to finer particles requires greater energy and results in higher carbon emissions.

    “Grinding to finer particles requires greater energy and results in higher carbon emissions.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Findingnone given

    ERW estimated costs are comparable to current estimates for the intensive carbon removal technologies, BECCS and DAC.

    “ERW estimated costs are comparable to current estimates for the intensive carbon removal technologies, BECCS and DAC”
    Quote in the paperNot a substantial claim

  • The quote only partly states this claim.

    Findingown data

    The results show close correspondence between the RTM and the calibrated performance model across all three flow regimes for tholeiitic basalt.

    “The results show close correspondence between models across all three flow regimes.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    At the two higher flow rates, shorter residence times result in less solute accumulation within the soil profile and a weaker chemical affinity effect.

    “At the two higher flow rates, shorter residence times result in less solute accumulation within the soil profile and a weaker chemical affinity effect.”
    • Also stated in: § Capital · plain
      “At the two higher flow rates, shorter residence times result in less solute accumulation within the soil profile and a weaker chemical affinity effect.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Weathering inhibition appears negligible over the 1 year duration of soil weathering, other than for laboradorite, with the performance model realistically capturing the effects of chemical affinity.

    “Weathering inhibition appears negligible over the 1 year duration of soil weathering, other than for laboradorite, with the performance model realistically capturing the effects of chemical affinity.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingreasoning

    Labradorite dissolves to completion after 365 days, and the results of the simulations that include and neglect affinity effects converge.

    “Consequently, labradorite dissolves to completion after 365 days, and the results of the simulations that include and neglect affinity effects converge.”
    • Also stated in: § Capital · plain
      “Consequently, labradorite dissolves to completion after 365 days, and the results of the simulations that include and neglect affinity effects converge.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Kfeldspar exerts a minor affinity effect but is present in such low concentrations that its influence on the basalt-porewater system can be considered negligible.

    “Kfeldspar also exerts a minor affinity effect but is present in such low concentrations that its influence on the basalt-porewater system can be considered to be negligible.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingreasoning

    Mining costs calculated using the method were 5.33, 4.44, 3.97, 4.88, 6.79 and 5.42 $ t-1 for China, India, Indonesia, Mexico, Canada and Brazil, respectively, and 7.90, 8.26, 6.76, 8.30 and 7.31 $ t-1 for France, Germany, Poland, Italy and Spain, respectively.

    “Mining costs for China, India, Indonesia, Mexico, Canada and Brazil calculated using the method were 5.33, 4.44, 3.97, 4.88, 6.79 and 5.42 $ t -1 , respectively and for France, Germany, Poland, Italy and Spain 7.90, 8.26, 6.76, 8.30 and 7.31 $ t -1 , respectively.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Under the BAU scenario, CO2 emissions from grinding dominate secondary emissions associated with ERW, except for France where low carbon nuclear power dominates.

    “Under the BAU scenario, CO2 emissions from grinding dominate secondary emissions associated with ERW, except for France where low carbon nuclear power dominates.”
    Quote in the paperNot a substantial claim

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

    Findingcitation

    Rail CO2 emissions were the same for both the business-as-usual (BAU) and 2°C scenarios.

    “Rail CO2 emissions were thus the same for both the business-as-usual (BAU) and 2°C scenarios.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [31] DeLucia, E., Kantola, I., Blanc-Betes, E., Bernacchi, C. & Beerling, D. J. Basalt application for carbon sequestration reduces nitrous oxide fluxes from cropland. Geophys. Res. Abstr. 21, EGU2019–EGU4500 (2019).

      Not checked in the free run.

  • The quote only partly states this claim.

    Findingown data

    Results for the 2°C energy policy scenario are very similar to the business-as-usual scenario.

    “Results for the 2°C energy policy scenario are very similar.”
    Quote in the paperNot a substantial claim

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

    Findingown data

    Only labradorite in these basalts exhibits noticeable effects of the chemical affinity term.

    “Only labradorite (green line) in these basalts exhibits noticeable effects.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation
    § The potential for large-scale CO 2 removal via rock weathering on croplands

    ERW has potential co-benefits for improved food and soil security and reduced ocean acidification.

    “ERW has potential co-benefits for improved food and soil security and reduced ocean acidification [2][3][4] .”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [2][3][4]

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Such effects would further lower adverse impacts of agriculture on climate per unit yield, amplifying the climate mitigation potential of ERW.

    “Such effects would further lower adverse impacts of agriculture on climate per unit yield, amplifying the climate mitigation potential of ERW.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationown data

    These patterns reflect expansion of ERW into climatically unfavourable agricultural land, causing CDR potential to slow relative to the carbon penalty of logistical operations, and the 3% limit in national energy available for grinding.

    “These patterns reflect expansion of ERW into climatically unfavourable agricultural land, causing CDR potential to slow relative to the carbon penalty of logistical operations, and the 3% limit in national energy available for grinding (Extended Data Fig. 2).”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

    Interpretationnone given
    § The potential for large-scale CO 2 removal via rock weathering on croplands

    Deployment with existing croplands offers opportunities to align agriculture and climate policy.

    “Deployment with existing croplands offers opportunities to align agriculture and climate policy.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation
    § The potential for large-scale CO 2 removal via rock weathering on croplands

    Rapid deployment at large scale appears feasible within decades, with important ancillary benefits including mitigation of ocean acidification.

    “Thus, rapid deployment at large scale appears feasible within decades, with important ancillary benefits including mitigation of ocean acidification [15][16][17][18] .”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [15][16][17][18]

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Efficacy of CO2 removal, sink saturation, and permanency of storage with these approaches, separately and interactively, are uncertain.

    “However, efficacy of CO2 removal, sink saturation, and permanency of storage with these approaches, separately and interactively, are uncertain 11,23 .”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [11] The Royal Society Greenhouse Gas Removal Technologies (The Royal Society, 2018).

      Not checked in the free run.

    • cites [23] Fuss, S. et al. Negative emissions—Part 2: Costs, potentials and side effects. Environ. Res. Lett. 13, 063002 (2018). source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Abatement of soil N2O emissions by basalt application to conventionally managed arable and perennial crops, and of N2O and CH4 emissions by application of artificial silicates to rice agriculture, is possible.

    “Abatement of soil N2O emissions by basalt application to conventionally managed arable and perennial crops 31 , and of N2O and CH4 emissions by application of artificial silicates to rice agriculture 32 , is possible.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [31] DeLucia, E., Kantola, I., Blanc-Betes, E., Bernacchi, C. & Beerling, D. J. Basalt application for carbon sequestration reduces nitrous oxide fluxes from cropland. Geophys. Res. Abstr. 21, EGU2019–EGU4500 (2019).

      Not checked in the free run.

    • cites [32] Das, S. et al. Cropping with slag to address soil, environment, and food security. Front. Microbiol. 10, 1320 (2019). source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S1 (asserted), S3 (load-bearing).

    Premisecitation
    § The potential for large-scale CO 2 removal via rock weathering on croplands

    Projections of rapid technological change suggest a lower requirement of 2-2.5 Gt CO2 yr -1.

    “although projections of rapid technological change 5 suggest a lower requirement of 2-2.5 Gt CO2 yr -1”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [5] Mercure, J.-F. et al. Macroeconomic impact of stranded fossil fuel assests. Nat. Clim. Chang. 8, 588–593 (2018). source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Most of the top 10 fossil carbon emitting nations are failing to meet their 2030 NDC pledges, which even if met imply a median warming of 2.6-3.1 °C, exceeding the Paris Agreement.

    “As yet, most of the top 10 fossil carbon emitting nations are failing to meet their 2030 NDC pledges which, even if met, imply a median warming (2.6-3.1 °C) exceeding the Paris agreement 33 .”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [33] Rogelj, J. et al. Paris Agreement climate proposals need a boost to keep warming well below 2 °C. Nature 534, 631–639 (2016). source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    ERW avoids competition for land used in food production, and related increased demands of BECCS for freshwater and polluting fertilizers, with CO2 being treated as a resource for mineral weathering.

    “ERW avoids competition for land used in food production, and related increased demands of BECCS for freshwater and polluting fertilizers 25 , with CO2 being treated as a resource for mineral weathering.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [25] Heck, V., Gerten, D., Lucht, W. & Popp, A. Biomass-based negative emissions difficult to reconcile with planetary boundaries. Nat. Clim. Chang. 8, 151–155 (2018). source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation
    § The potential for large-scale CO 2 removal via rock weathering on croplands

    Basalt is an abundant fast-weathering rock with the required mineral chemistry, and is a prime target for implementing land-based ERW because of its potential co-benefits for crop production and soil health.

    “Basalt, an abundant fast-weathering rock with the required mineral chemistry, is a prime target for implementing land-based ERW because of its potential cobenefits for crop production 18 and soil health [2][3][4] .”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [18] Kelland, M. E. et al. Increased yield and CO2 sequestration potential with the C4 cereal crop Sorghum bicolor cultivated in basaltic rock dust amended agricultural soil. Glob. Change Biol. 26, 3658–3676 (2020). source

      Not checked in the free run.

    • cites [2][3][4]

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    Inorganic carbon sequestration by ERW appears comparable to SOC sequestration (~2.5 Gt CO2 yr -1 by 2100) using agricultural land, but with potentially greater long-term security of C-storage.

    “Inorganic carbon sequestration by ERW appears comparable to SOC sequestration, another proposed CDR strategy (~2.5 Gt CO2 yr -1 by 2100) 27 using agricultural land, but with potentially greater long-term security of C-storage.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [27] Mayer, A. et al. The potential of agricultural land management to contribute to lower global surface temperature. Sci. Adv. 4, eaaq0932 (2018). source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    NDC pledged carbon emission reductions undergo periodic revision in response to trends in greenhouse gas emissions, uptake of low-carbon energy technology, and climate, and hence are not set for 2050.

    “NDC pledged carbon emission reductions undergo periodic revision in response to trends in greenhouse gas emissions, uptake of low-carbon energy technology, and climate 33 and hence are not set for 2050.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [33] Rogelj, J. et al. Paris Agreement climate proposals need a boost to keep warming well below 2 °C. Nature 534, 631–639 (2016). source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation
    § The potential for large-scale CO 2 removal via rock weathering on croplands

    ERW liberates base cations, generating alkalinity such that atmospheric CO2 is converted into dissolved inorganic carbon (principally hydrogen carbonate ions; HCO3-) that is removed via soil drainage waters.

    “ERW liberates base cations, generating alkalinity such that atmospheric CO2 is converted into dissolved inorganic carbon (principally hydrogen carbonate ions; HCO3 -) that is removed via soil drainage waters.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [2][3][4][13][14][15][16][17]

      Not checked in the free run.

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

    Premisecitation

    Cement contributes ~6% to global CO2 emissions.

    “Cement contributes ~6% to global CO2 emissions 6 and ERW may represent a land management option for valorising by-products to capture carbon and improve the sustainability of this worldwide industry.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [6] Le Quéré, C. et al. Global carbon budget 2018. Earth Syst. Sci. Data 10, 2141–2194 (2018).

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationreasoning

    This increases the potential to bring smallholders out of extreme poverty and, in regions with climates suitable for non-irrigated agriculture, restore highly degraded soils not suitable currently for food production.

    “This increases the potential to bring smallholders out of extreme poverty and, in the regions with climates suitable for non-irrigated agriculture, restore highly degraded soils not suitable currently for food production.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation

    These negative effects may be reversible with ERW treatments given fertilization of irrigated rice using either natural and/or artificial silicates replenishing plant available silica pools, increasing yields and soil pH, and decreasing the mobility of potentially toxic trace elements (e.g., arsenic).

    “Yet these negative effects may be reversible with ERW treatments given fertilization of irrigated rice using either natural and/or artificial silicates (e.g., recycled steel slags) replenishing plant available silica pools, increasing yields and soil pH, and decreasing the mobility of potentially toxic trace elements (e.g., arsenic) 46 .”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [46] Ning, D. et al. Impacts of steel-slag-based fertilizer on soil acidity and silicon availability and metals-immobilization in a paddy soil. PLoS One 11, e0168163 (2016). source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based).

    Interpretationnone given

    Understanding the balance between positive and negative outcomes in terms of public acceptance of the inevitable trade-offs between local mining activities versus global sequestered carbon requires empirical testing with stakeholders and the wider public.

    “Understanding the balance between positive and negative outcomes in terms of public acceptance of the inevitable trade-offs between local mining activities versus global sequestered carbon, requires empirical testing with stakeholders and the wider public.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Mining generates a continuous but usually discarded finely powered silicate byproduct utilizable for ERW without embodied CO2 emissions that reduce CDR efficiency, and which has been accumulating worldwide for decades.

    “Mining generates a continuous but usually discarded finely powered silicate byproduct utilizable for ERW without embodied CO2 emissions that reduce CDR efficiency (Extended Data Fig. 6) [21][22][23] , and which has been accumulating worldwide for decades.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [21][22][23]

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationnone given

    Realizing the potential of ERW as a biogeochemical approach to sequester CO2 by altering land management practices depends on the commitment of farmers and governments, implementation of the right policy frameworks, and wider public acceptance.

    “Realizing the potential of ERW as a biogeochemical approach to sequester CO2 by altering land management practices will depend on the commitment of farmers and governments, implementation of the right policy frameworks, and wider public acceptance.”
    Quote in the paperNot a substantial claim

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

    Premisecitation

    Farming practices for increasing sustainable productivity have transformed agriculture across 37 million hectares in China, increasing profits by $12.2 billion over a decade.

    “Farming practices adopted for increasing sustainable productivity, for example, have transformed agriculture across 37 million hectares in China, increasing profits by $12.2 billion over a decade 50 .”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [50] Cui, Z. et al. Pursuing sustainable productivity with millions of smallholder farmers. Nature 555, 363–366 (2018). source

      Not checked in the free run.

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

    Premisecitation

    The current substantial rate of agricultural top-soil depletion requires urgent remedial action, with significant economic costs apparent already in China where degradation of soils supporting wheat, maize and rice production costs an estimated $12 billion annually.

    “The current substantial rate of agricultural top-soil depletion requires urgent remedial action, with significant economic costs apparent already in China where degradation of soils supporting wheat, maize and rice production costs an estimated $12 billion annually 48 .”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [48] United Nations Global Land Outlook 1st edn (United Nations Convention to Combat Desertification, 2017).

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Agricultural production can benefit substantially from increased resource use efficiency, reducing consumption of raw materials and recovering mineral nutrients from silicate byproducts and overburden legacy reserves.

    “Agricultural production can benefit substantially from increased resource use efficiency, reducing consumption of raw materials and recovering mineral nutrients from silicate byproducts 32,42,43 , and overburden legacy reserves 44 .”
    Quote in the paperNot a substantial claim0 of 4 sources checked
    • cites [32] Das, S. et al. Cropping with slag to address soil, environment, and food security. Front. Microbiol. 10, 1320 (2019). source

      Not checked in the free run.

    • cites [42] Haynes, R. J., Belyaeva, O. N. & Kingston, G. Evaluation of industrial waste sources of fertilizer silicon using chemical extractions and plant uptake. J. Plant Nutr. Soil Sci. 176, 238–248 (2013). source

      Not checked in the free run.

    • cites [43] Rodd, A. V. et al. Surface application of cement kiln dust and lime to forage land: effect on forage yield, tissue concentration and accumulation of nutrients. Can. J. Soil Sci. 90, 201–213 (2010). source

      Not checked in the free run.

    • cites [44] Ramos, C.G. et al. Evaluation of soil re-mineralizer from by-product of volcanic rock mining: experimental proof using black oats and maize crops. Nat. Res. Res. 10.1007/s11053–019–09529-x (2019). source

      Not checked in the free run.

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

    Interpretationreasoning

    ERW may represent a land management option for valorising by-products to capture carbon and improve the sustainability of the cement industry.

    “Cement contributes ~6% to global CO2 emissions 6 and ERW may represent a land management option for valorising by-products to capture carbon and improve the sustainability of this worldwide industry.”
    Quote in the paperNot a substantial claim

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

    Interpretationcitation

    Addition of trace amounts of zinc and iron could also improve public health by reversing the effect of rising CO2 levels on the declining nutritional value of food crops.

    “Addition of trace amounts of zinc and iron could also improve public health by reversing the effect of rising CO2 levels on the declining nutritional value of food crops 49 .”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [49] Smith, M. R. & Myers, S. S. Impact of anthropogenic CO2 emissions on global human nutrition. Nat. Clim. Chang. 8, 834–839 (2018). source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    China and India dominate with above-average per capita cement consumption compared to the global average, and substantially larger populations than the USA and Brazil.

    “China and India dominate with above-average per capita cement consumption compared to the global average, and substantially larger populations than the USA and Brazil 38 .”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [38] Renforth, P. The negative emission potential of alkaline materials. Nat. Commun. 10, 1401 (2019). source

      Not checked in the free run.

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

    Interpretationnone given

    Feasibility of mobilizing millions of smallholder communities to adopt ERW practices in China and India depends on demonstrating that soil improvements can reverse yield declines and on government subsidies.

    “Feasibility of mobilizing millions of smallholder communities to adopt ERW practices in China and India will depend on demonstrating soil improvements can reverse yield declines, and on government subsidies.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation

    Targeted amendment of agricultural soils for CO2 removal may have a role in slowing rates of soil loss by up to 45%, with the accelerated weathering of added minerals replacing inorganic nutrients and resultant formation of clays and mineral organic aggregates increasing the cation exchange capacity and water storage capacity of rebuilt soils.

    “Targeted amendment of agricultural soils for CO2 removal may have a role in slowing rates of soil loss by up to 45%, with the accelerated weathering of added minerals replacing inorganic nutrients and resultant formation of clays and mineral organic aggregates increasing the cation exchange capacity and water storage capacity of rebuilt soils 4,20 .”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [4] Beerling, D. J. et al. Farming with crops and rocks to address global climate, food and soil security. Nat. Plants 4, 138–147 (2018). source

      Not checked in the free run.

    • cites [20] Smith, P. et al. Land-based options for greenhouse gas removal and their impacts on ecosystem services and the sustainable development goals. Annu. Rev. Environ. Res. 44, 255–286 (2019). source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable). May combine two claims.

    Interpretationcitation

    A similar outreach programme to that used for sustainable productivity farming could be used throughout Asia, with farmers earning more profits from higher yields while sequestering CO2.

    “With 2.5 billion smallholders farming 60% of the world's arable land, a similar outreach programme could be used throughout Asia, with farmers earning more profits from higher yields while sequestering CO2.”
    Quote in the paperNot a substantial claim
    • Rests on an assumption: There are 2.5 billion smallholders farming 60% of the world's arable land.

  • May combine two claims.

    Premisecitation

    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 .”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [40] Washbourne, C.-L. et al. Rapid removal of atmospheric CO2 in urban soils. Environ. Sci. Technol. 49, 5434–5440 (2015). source

      Not checked in the free run.

    • cites [41] Lekakh, S. N. et al. Kinetics of aqueous leaching and carbonization of steelmaking slag. Metallurg. Mater. Trans. B 39, 125–134 (2008). source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Current fossil fuel emissions per person per year are 16.5 t CO2 (USA), 15.1 t CO2 (Canada), 7.5 t CO2 (China), 7.3 t CO2 (EU28), 2.6 t CO2 (Brazil), 1.8 t CO2 (Indonesia) and 1.7 t CO2 (India).

    “Current fossil fuel emissions per person per year 6 are 16.5 t CO2 (USA), 15.1 t CO2 (Canada), 7.5 t CO2 (China), 7.3 t CO2 (EU28), 2.6 t CO2 (Brazil), 1.8 t CO2 (Indonesia) and 1.7 t CO2 (India).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [6] Le Quéré, C. et al. Global carbon budget 2018. Earth Syst. Sci. Data 10, 2141–2194 (2018).

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Interpretationcitation

    Such testing needs to understand the conditions that society might place upon the development and large-scale deployment of ERW technologies, as part of a wider responsible research and innovation programme.

    “Crucially, such testing needs to understand the conditions that society might place upon the development and large-scale deployment of ERW technologies, as part of a wider responsible research and innovation programme 51 .”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [51] Pidgeon, N. F. & Spence, E. Perceptions of enhanced weathering as a biological negative emissions option. Biol. Lett. 13, 20170024 (2017). source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    At this early stage of research and development, ERW costs are uncertain and in need of demonstration projects.

    “At this early stage of research and development, costs are uncertain and in need of demonstration projects 7,11,12 .”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [7] United Nations Environment Programme The Emissions Gap Report 2018 (United Nations Environment Programme, 2018).

      Not checked in the free run.

    • cites [11] The Royal Society Greenhouse Gas Removal Technologies (The Royal Society, 2018).

      Not checked in the free run.

    • cites [12] Pacala, S. et al. Negative Emissions Technologies And Reliable Sequestration (National Academy of Sciences, 2018).

      Not checked in the free run.

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

    Interpretationreasoning

    The ancillary benefits of ERW may aid its early use and relieve concern about erosion of climate threat perception.

    “The ancillary benefits of ERW may aid its early use and relieve such concern.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    These functions represent the effects of a range of rhizosphere processes that accelerate the physical breakdown and chemical dissolution of minerals, including the activities of nutrient scavenging mycorrhizal fungi that physically disrupt and chemically etch mineral surfaces, and bio-production of low molecular weight organic compounds and chelating agents.

    “These functions represent the effects of a range of rhizosphere processes that accelerate the physical breakdown and chemical dissolution of minerals, including the activities of nutrient scavenging mycorrhizal fungi that physically disrupt and chemically etch mineral surfaces, and bio-production of low molecular weight organic compounds and chelating agents 63,64 .”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [63] Harley, A. D. & Gilkes, R. J. Factors influencing the release of plant nutrient elements from silicate rock powders: a geochemical overview. Nutr. Cycl. Agroecosyst. 56, 11–36 (2000). source

      Not checked in the free run.

    • cites [64] Taylor, L. L. et al. Biological evolution and the long-term carbon cycle: integrating mycorrhizal evolution and function into the current paradigm. Geobiology 7, 171–191 (2009). source

      Not checked in the free run.

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

    Premisecitation

    Nations that may have large ERW potential, including China, the United States and India, are all vulnerable to climate change and resultant sea-level rise.

    “Nations that may have large ERW potential, including China, the United States and India, are all vulnerable to climate change and resultant sea-level rise 34 .”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [34] Clark, P. U. et al. Consequences of twenty-first-century policy for multi-millennial climate and sea-level change. Nat. Clim. Chang. 6, 360–369 (2016). source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The fractal dimension for surface roughness provides a means of consolidating measurements taken at different scales and accounts for uncertainties in grain topography and porosity and mass transfer rates from rock grains to flowing soil water.

    “The fractal dimension effectively provides a means of consolidating measurements taken at different scales and accounts for uncertainties in grain topography and porosity 72 , and mass transfer rates from rock grains to flowing soil water.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [72] Brantley, S. L. & Mellott, N. P. Surface area and porosity of primary silicate minerals. Am. Mineral. 85, 1767–1783 (2000). source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    CDR via pathway 2 sequesters 1 mol of CO2 per mole of Ca2+ and is therefore less efficient than pathway 1.

    “CDR via pathway 2 can occur if dissolved inorganic carbon derived from atmospheric CO2 precipitates as pedogenic carbonate, and sequesters 1 mol of CO2 per mole of Ca 2+ instead of 1.72 mol of CO2 via pathway 2 and is therefore less efficient.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: Weathering products liberated from primary minerals are assumed to subsequently reach the surface ocean via continental runoff.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    The potential for trapping of weathered cations on ion exchange surfaces or within secondary minerals other than carbonates delaying, or even preventing, land-ocean transfer will depend on soil type, climate, hydrological conditions, application rate and management practices.

    “The potential for trapping of weathered cations on ion exchange surfaces or within secondary minerals other than carbonates delaying, or even preventing, land-ocean transfer will depend on soil type, climate, hydrological conditions, application rate and management practices.”
    Quote in the paperNot a substantial claim

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

    Study design and conductnone given

    Possible CO2 degassing due to changes in surface water chemistry during transport in large river systems is not considered.

    “Possible CO2 degassing due to changes in surface water chemistry during transport in large river systems 74 is not considered.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [74] Salisbury, J. E. et al. Seasonal observations of surface waters in two Gulf of Maine estuary-plume systems: relationships between watershed attributes, optical measurements and surface p CO2. Estuar. Coast. Shelf Sci. 77, 245–252 (2008). source

      Not checked in the free run.

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

    Study design and conductnone given

    Our analysis of the techno-economic potential of CDR by ERW is subject to several uncertainties, particularly variation in our baseline application rate and basalt mineralogy.

    “Our analysis of the techno-economic potential of CDR by ERW is subject to several uncertainties, particularly variation in our baseline application rate and basalt mineralogy.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Study design and conductnone given

    We have not considered the penetration of recycling into steel production beyond its current rate.

    “We have not considered the penetration of recycling into steel production beyond its current rate.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation

    Innovative 'climate-smart' farming practices can be designed with ERW to draw down CO2 and other greenhouse gases while recycling nutrients, aiding soil water storage, and supporting crop production.

    “Innovative 'climate-smart' farming practices can be designed with ERW to draw down CO2 and other greenhouse gases while recycling nutrients, aiding soil water storage, and supporting crop production 4,18,20 .”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [4] Beerling, D. J. et al. Farming with crops and rocks to address global climate, food and soil security. Nat. Plants 4, 138–147 (2018). source

      Not checked in the free run.

    • cites [18] Kelland, M. E. et al. Increased yield and CO2 sequestration potential with the C4 cereal crop Sorghum bicolor cultivated in basaltic rock dust amended agricultural soil. Glob. Change Biol. 26, 3658–3676 (2020). source

      Not checked in the free run.

    • cites [20] Smith, P. et al. Land-based options for greenhouse gas removal and their impacts on ecosystem services and the sustainable development goals. Annu. Rev. Environ. Res. 44, 255–286 (2019). source

      Not checked in the free run.

  • The quote only partly states this claim.

    Study design and conductown data

    We addressed the uncertainty from extrapolation of laboratory weathering rates by Monte Carlo analysis of the fractal dimension accounting for uncertainty in the apparent reacting surface area of grains for ERW conducted at large geographical scales.

    “We addressed this by Monte Carlo analysis of the fractal dimension accounting for uncertainty in the apparent reacting surface area of grains for ERW conducted at large geographical scales.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Duration of carbon sequestration rate, and possibility for CO2 sink saturation with ERW on croplands, are both poorly constrained by data, in common with other land-based CDR strategies, and affect cumulative CDR potential in coming decades.

    “Duration of carbon sequestration rate, and possibility for CO2 sink saturation with ERW on croplands, are both poorly constrained by data, in common with other land-based CDR strategies 11,23 , and affect cumulative CDR potential in coming decades.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [11] The Royal Society Greenhouse Gas Removal Technologies (The Royal Society, 2018).

      Not checked in the free run.

    • cites [23] Fuss, S. et al. Negative emissions—Part 2: Costs, potentials and side effects. Environ. Res. Lett. 13, 063002 (2018). source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing).

    Interpretationcitation

    Their high risks of economic damage and social disruption provide impetus for creative co-design of agricultural and climate policies.

    “Their high risks of economic damage 53 and social disruption provide impetus for creative co-design of agricultural and climate policies.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [53] Ricke, K., Drout, L., Caldeira, K. & Tavoni, M. Country-level social cost of carbon. Nat. Clim. Chang. 8, 895–900 (2018). source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    Such practices can help restore deteriorating top-soils that underpin food security for billions of people while maximizing societal co-benefits needed to incentivise deployment.

    “Such practices can help restore deteriorating top-soils that underpin food security for billions of people while maximizing societal co-benefits needed to incentivise deployment 20 .”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [20] Smith, P. et al. Land-based options for greenhouse gas removal and their impacts on ecosystem services and the sustainable development goals. Annu. Rev. Environ. Res. 44, 255–286 (2019). source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationreasoning

    Calculating representative annual CO2 removal rates requires computing average rates derived from repeated basaltic rock dust applications.

    “Thus calculating representative annual CO2 removal rates requires computing average rates derived from repeated basaltic rock dust applications (Extended Data Fig. 7).”
    • Also stated in: § Extended · plain
      “Thus calculating representative annual CO2 removal rates requires computing average rates derived from repeated basaltic rock dust applications.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    CDR via pathway 2 sequesters 1 mol of CO2 per mole of Ca2+ instead of 1.72 mol of CO2 via pathway 1 and is therefore less efficient.

    “CDR via pathway 2 occurs if dissolved inorganic CO2 precipitates as pedogenic carbonate, and sequesters 1 mol of CO2 per mole of Ca 2+ instead of 1.72 mol of CO2 via pathway 1 and is therefore less efficient.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductcitation

    The fractal dimension and its uncertainty are determined from a linear regression analysis performed on measurements from a range of spatial scales (10−10-103 m).

    “The fractal dimension and its uncertainty are determined from a linear regression analysis performed on measurements from a range of spatial scales 3 (10 -10 -10 3 m).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [3] Zhang, G., Kang, J., Wang, T. & Zhu, C. Review and outlook for agromineral research in agriculture and climate change mitigation. Soil Res. 56, 113–122 (2018). source

      Not checked in the free run.

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

    Premisecitation

    Functions are fitted to mesocosm data for three species of agricultural crops (maize, rice and soybean) and four species of mycorrhizal tree saplings.

    “Functions are fitted to mesocosm data for (a) three speies of agricultural crops (maize, rice and soybean) 46,47 , and (b) four species of mycorrhizal tree saplings 48,49 .”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [46] Ning, D. et al. Impacts of steel-slag-based fertilizer on soil acidity and silicon availability and metals-immobilization in a paddy soil. PLoS One 11, e0168163 (2016). source

      Not checked in the free run.

    • cites [47] Chen, J. Rapid urbanization in China: a real challenge to soil protection and food security. Catena 69, 1–15 (2007). source

      Not checked in the free run.

    • cites [48] United Nations Global Land Outlook 1st edn (United Nations Convention to Combat Desertification, 2017).

      Not checked in the free run.

    • cites [49] Smith, M. R. & Myers, S. S. Impact of anthropogenic CO2 emissions on global human nutrition. Nat. Clim. Chang. 8, 834–839 (2018). source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    The extent to which simulated pH increases promote or adversely affect crop production depends on the initial topsoil pH, crop functional traits, weathering rates, climate, flushing rates and fertiliser treatments.

    “The extent to which simulated pH increases promote or adversely affect crop production depends on the initial topsoil pH, crop functional traits, weathering rates, climate, flushing rates and fertiliser treatments.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationnone given

    These functions represent the lumped effects of rhizosphere biological processes accelerating weathering.

    “These functions represent the lumped effects of rhizosphere biological processes accelerating weathering (Section 1.9).”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationreasoning

    The lower price for China, India and Brazil reflects low labour costs while the higher price for France and Germany reflects higher diesel costs.

    “The lower price for China, India and Brazil reflects low labour costs while the higher price for France and Germany reflects higher diesel costs.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S2 (checkable), S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationnone given

    Our costs are indicative of key features of an ERW supply chain and consistent with previous global approaches.

    “Our cost are indicative of key features of an ERW supply chain and consistent with previous global approaches.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: Cost of spreading rock with farming machinery is equivalent to that of spreading lime ($15.18/t).

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

    Premiseown data

    The exceptions to the low leachate elemental concentrations are Sb and Se.

    “The exceptions are Sb and Se.”
    Quote in the paperNot a substantial claim

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

    Premisecitation

    Basaltic glass powder with a diameter of 40-120 μm has a roughness factor (lambda) of ~92.

    “For comparison, basaltic glass powder with a diameter of 40 -120µm has a lambda 50 of ~92.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [50] Cui, Z. et al. Pursuing sustainable productivity with millions of smallholder farmers. Nature 555, 363–366 (2018). source

      Not checked in the free run.

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

    Premisecitation

    Sb and Se are less concentrated in the unmixed cement waste.

    “However, these are less concentrated in the unmixed cement waste 59 .”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [59] Siebert, S. & Doll, P. Quantifying blue and green virtual water contents in global crop production as well as potential production losses without irrigation. J. Hydrol. 384, 198–217 (2010). source

      Not checked in the free run.

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

    Interpretationreasoning

    Uncertainty in the fractal dimension affects weathering rate and consequently, through the optimization, the p80 grid cell vector.

    “Uncertainty in the fractal dimension affects weathering rate and consequently, through the optimization, the p80 grid cell vector.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    The affinity effect on labradorite is greatest during the first 100 days, especially under a low flow rate (200 mm yr -1), because there is little dilution of the weathered products, resulting in higher pore water concentrations exerting a stronger affinity effect.

    “This is greatest during the first 100 days, especially under a low flow rate (200 mm yr -1 top panels) because there is little dilution of the weathered products, resulting in higher pore water concentrations exerting a stronger affinity effect.”
    Quote in the paperNot a substantial claim
85 of 85

  • The paper relies on this without support.

    There are 2.5 billion smallholders farming 60% of the world's arable land.

    “With 2.5 billion smallholders farming 60% of the world's arable land”

  • The paper relies on this without support.

    Surface passivation occurs as weathering proceeds, creating leached layers and relatively stable secondary minerals, which potentially inhibit the mass transfer kinetics of elements from the dissolving surfaces of primary minerals.

    “Surface passivation, a component of chemical inhibition, occurs as weathering proceeds, creating leached layers and relatively stable secondary minerals, which potentially inhibit the mass transfer kinetics of elements from the dissolving surfaces of primary minerals.”

  • The authors state this as an assumption.

    Weathering products liberated from primary minerals are assumed to subsequently reach the surface ocean via continental runoff.

    “Carbon dioxide removal (CDR) results from the mass transport of enhanced weathering products liberated from the primary minerals, which are assumed to subsequently reach the surface ocean via continental runoff, or can be precipitated as secondary carbonate minerals in the terrestrial environment.”

  • The authors state this as an assumption.

    Particles are assumed to be spherical.

    “As particles are assumed to be spherical, we reformulate equation 14 in terms radius rather than mass to give:”

  • The authors state this as an assumption.

    The scrap ratio remains unchanged.

    “The ratio of pig iron to steel production (0.72) was obtained using linear regression of 1960-2014 data, negating the need to explicitly model pig iron displacement from scrap recycling, and assuming the scrap ratio remains unchanged.”
    “assuming the scrap ratio remains unchanged.”

  • The authors state this as an assumption.

    All steel and blast furnace slag is available for reaction with CO2.

    “All steel and blast furnace slag was considered available for reaction with CO2.”
    “All steel and blast furnace slag was considered available for reaction with CO2.”

  • The paper relies on this without support.

    Cement and cement kiln dust have no capacity to be recycled as cement.

    “Cement and cement kiln dust have no capacity to be recycled as cement.”
    “Cement and cement kiln dust have no capacity to be recycled as cement.”

  • The paper relies on this without support.

    In the tropics and subtropics, annual temperature variation is relatively low.

    “In the tropics and subtropics, where perennial crops dominate, annual temperature variation is relatively low.”

  • The paper relies on this without support.

    The soil surface temperature at 5 cm depth of the 8 warmest months for 2050 represents conditions during the main growth period of most crop types found outside the tropics.

    “This value is taken to represent conditions during the main growth period of most crop types found outside the tropics.”

  • The paper relies on this without support.

    Standard calculations of rate of mineral dissolution ignore size differences in reacting particles and simulate the mineral with a surface area that corresponds to the mean diameter of a particle size distribution.

    “Standard calculations of rate of mineral dissolution ignore size differences in reacting particles and simulate the mineral with a surface area that corresponds to the mean diameter of a particle size distribution (psd).”

  • The authors state this as an assumption.

    Land management practices for annual crops return cations released during dissolution, and taken up by crops back to soils via biomass decomposition.

    “We assume land management practices for annual crops return cations released during dissolution, and taken up by crops back to soils via biomass decomposition.”

  • The authors state this as an assumption.

    Cost of spreading rock with farming machinery is equivalent to that of spreading lime ($15.18/t).

    “Cost of spreading rock with farming machinery was considered equivalent to that of spreading lime ($15.18/t).”

  • The authors state this as an assumption.

    A future limit of 3% of total energy production for rock comminution for all nations.

    “We assume a future limit of 3% for all nations, based on the rationale that current rates for developed nations grow from around 2% today in-line with future energy scenarios 33 .”

  • The authors state this as an assumption.

    115 kg of cement kiln dust is produced as a by-product in kilns for every tonne of clinker, and demolition waste follows an average 50-year service life (normally distributed with standard deviation 10 years).

    “We assume 115 kg of cement kiln dust is produced as a by-product in kilns for every tonne of clinker, and have modelled the production of demolition waste following an average 50-year service life (normally distributed with a standard deviation of 10 years) 41 .”

  • The authors state this as an assumption.

    Interstitial waters are in equilibrium with dissolved weathering products, inorganic and organic soil cation exchange surfaces and secondary minerals.

    “Interstitial waters are calculated to be in equilibrium with the dissolved weathering products, inorganic and organic soil cation exchange surfaces and secondary minerals.”

  • The authors state this as an assumption.

    Secondary minerals form and dissolve instantaneously to maintain thermodynamic equilibrium between the fluid and mineral phases.

    “These were calculated to form and dissolve instantaneously to maintain thermodynamic equilibrium between the fluid and mineral phases.”

  • The authors state this as an assumption.

    The soil solution is in equilibrium with atmospheric pO2(g).

    “The soil solution was equilibrated with dissolved O2 and CO2; assuming equilibrium with atmospheric pO2(g) (atm).”
17 of 17

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?

  • Application of crushed calcium- and magnesium-rich silicate rocks to soils (enhanced rock weathering) increases soil alkalinity, converting atmospheric CO2 into dissolved inorganic C transported to the ocean where stored C has a long lifespan.

    “Application of crushed calcium- and magnesium-rich silicate rocks to soils is proposed for large-scale CO2 removal.191 This technology was called enhanced rock weathering, which increases soil alkalinity, and thus atmospheric CO2 can be converted into dissolved inorganic C to be finally transported to the ocean, where the stored C has a long lifespan via land surface runoff.”

    From Technologies and perspectives for achieving carbon neutrality (2021) · cites this paper as [191]

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.

  • Carbon-price range is said to cover costs in all nations despite higher reported costs

    Major

    The projected carbon-price range is $100-150 per tonne, but the paper reports average costs of $160-180 for the USA and $160-190 for Canada and European nations. Those averages are outside the range, contrary to the claim that costs are generally within it in all nations.

  • Optimization uses 2030 electricity production in a 2050 assessment

    Minor

    The optimization constraint specifies projected grid electricity production for 2030, whereas the stated optimization inputs and national energy projections are for 2050.

  • Carbonate pathway is mislabeled as the comparison pathway

    Minor

    The sentence contrasts carbonate formation (pathway 2) with ocean-bound cations but calls the latter pathway 2 as well. The paper elsewhere assigns ocean-bound cations to pathway 1.

  • Water-quality exceptions omit three elements above their listed standards

    Minor

    Table S15 lists aluminium, calcium and potassium concentrations above their respective stated water-quality standards. The accompanying text identifies only Sb and Se as exceptions.

4 of 4

Cites

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Cited by

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Related

Authors
Beerling, D. J., Kantzas, E. P., Lomas, M. R., Wade, P., Eufrasio, R. M., Renforth, P., Sarkar, B., Andrews, M. G., James, R. H., Pearce, C. R., Mercure, J.-F., Pollitt, H., Holden, P. B., Edwards, N. R., Khanna, M., Koh, L., Quegan, S., Pidgeon, N. F., Janssens, I. A., Hansen, J., & Banwart, S. A.
Affiliations
  • Leverhulme Centre for Climate Change Mitigation (GB)
  • University of Sheffield (GB)
  • Heriot-Watt University (GB)
  • Lancaster University (GB)
  • National Oceanography Centre (GB)
  • University of Cambridge (GB)
  • The Open University (GB)
  • University of Illinois Urbana-Champaign (US)
  • Cardiff University (GB)
  • University of Antwerp (BE)
  • Columbia University (US)
  • University of Leeds (GB)
Corresponding author
Beerling, David J.
ORCID
Venue
Nature
Publisher
Springer Science and Business Media LLC
Published
2020-07-08
Volume
583
Issue
7815
Pages
242-248
ISSN
  • 0028-0836 (ISSN-L)
  • 1476-4687
DOI
10.1038/s41586-020-2448-9
OpenAlex
W3041773269
Semantic Scholar
9c00c1ebacb3a72cae19f74c126391c7eb38ebc1
Cited by
700
References
78
Citations by year
2026: 137 · 2025: 144 · 2024: 144 · 2023: 100 · 2022: 94 · 2021: 71 · 2020: 10
FWCI
24.79
Type
journal article
Language
en
Open access
Licence
Locations
  • Nature (publishedVersion)
  • PubMed (publishedVersion)
  • Lancaster EPrints (Lancaster University) (acceptedVersion)
  • ePrints Soton (University of Southampton) (acceptedVersion)
  • White Rose Research Online (University of Leeds, The University of Sheffield, University of York) (acceptedVersion)
  • NERC Open Research Archive (Natural Environment Research Council) (acceptedVersion)
  • Open Research Online - ORO (The Open University) (acceptedVersion)
  • Open Research Exeter (University of Exeter) (acceptedVersion)
  • RePEc: Research Papers in Economics (submittedVersion)
  • Adelaide Research & Scholarship (AR&S) (University of Adelaide) (submittedVersion)
  • Figshare (submittedVersion)
  • ORCA Online Research @Cardiff (Cardiff University) (submittedVersion)
Funders
  • U.S. Department of Energy
  • UK Research and Innovation
  • Leverhulme Trust (RC-2015-029)
  • Royal Academy of Engineering
  • Universiteit Antwerpen
  • Engineering and Physical Sciences Research Council (EP/K007254/1)
  • Natural Environment Research Council (noc010011, NE/P015093/1, NE/P019943/2, NE/S017119/1, NE/P019730/2, NE/P019943/1)
Topics
  • Physical Sciences › Environmental Science › Environmental Engineering › CO2 Sequestration and Geologic Interactions
  • Physical Sciences › Engineering › Mechanical Engineering › Carbon Dioxide Capture Technologies
  • Physical Sciences › Environmental Science › Global and Planetary Change › Climate Change and Geoengineering
Keywords
carbon dioxide removal, cropland, techno-economic analysis, climate change mitigation, 2°C target, energy policy scenarios
MeSH terms
Agriculture, Atmosphere, Brazil, Carbon Dioxide, China, Goals, India, Iron, Mining, Politics, Probability, Steel, Temperature, Time Factors, United States, Silicates, Crops, Agricultural, Geologic Sediments, Global Warming, Environmental Policy

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 ›

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