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

In the paper

“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).”

In the paper

“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).”

In the paper

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

In the paper

“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.”

In the paper

“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.”

In the paper

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

In the paper

“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).”

In the paper

“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 .”

What the sources say

• Not checked yetcites [23] Fuss, S. et al. Negative emissions—Part 2: Costs, potentials and side effects. Environ. Res. Lett. 13, 063002 (2018). source

In the paper

“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).”

In the paper

“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).”

What the sources say

• Not checked yetcites [21][22][23]

In the paper

“with potential for ancillary benefits by limiting coastal zone acidification and improving food and soil security”

In the paper

“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.”

In the paper

“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.”

In the paper

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

In the paper

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

In the paper

“The results show close correspondence between models across all three flow regimes.”

In the paper

“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.”

In the paper

“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.”

In the paper

“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.”

In the paper

“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.”

In the paper

“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.”

In the paper

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

In the paper

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

What the sources say

• Not checked yetcites [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).

In the paper

“Results for the 2°C energy policy scenario are very similar.”

In the paper

“Only labradorite (green line) in these basalts exhibits noticeable effects.”

In the paper

“ERW has potential co-benefits for improved food and soil security and reduced ocean acidification [2][3][4] .”

What the sources say

• Not checked yetcites [2][3][4]

In the paper

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

In the paper

“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).”

In the paper

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

In the paper

“Thus, rapid deployment at large scale appears feasible within decades, with important ancillary benefits including mitigation of ocean acidification [15][16][17][18] .”

What the sources say

• Not checked yetcites [15][16][17][18]

In the paper

“However, efficacy of CO2 removal, sink saturation, and permanency of storage with these approaches, separately and interactively, are uncertain 11,23 .”

What the sources say

• Not checked yetcites [11] The Royal Society Greenhouse Gas Removal Technologies (The Royal Society, 2018).
• Not checked yetcites [23] Fuss, S. et al. Negative emissions—Part 2: Costs, potentials and side effects. Environ. Res. Lett. 13, 063002 (2018). source

In the paper

“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.”

What the sources say

• Not checked yetcites [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 yetcites [32] Das, S. et al. Cropping with slag to address soil, environment, and food security. Front. Microbiol. 10, 1320 (2019). source

In the paper

“although projections of rapid technological change 5 suggest a lower requirement of 2-2.5 Gt CO2 yr -1”

What the sources say

• Not checked yetcites [5] Mercure, J.-F. et al. Macroeconomic impact of stranded fossil fuel assests. Nat. Clim. Chang. 8, 588–593 (2018). source

In the paper

“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 .”

What the sources say

• Not checked yetcites [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

In the paper

“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.”

What the sources say

• Not checked yetcites [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

In the paper

“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] .”

What the sources say

• Not checked yetcites [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 yetcites [2][3][4]

In the paper

“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.”

What the sources say

• Not checked yetcites [27] Mayer, A. et al. The potential of agricultural land management to contribute to lower global surface temperature. Sci. Adv. 4, eaaq0932 (2018). source

In the paper

“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.”

What the sources say

• Not checked yetcites [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

In the paper

“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.”

What the sources say

• Not checked yetcites [2][3][4][13][14][15][16][17]

In the paper

“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.”

What the sources say

• Not checked yetcites [6] Le Quéré, C. et al. Global carbon budget 2018. Earth Syst. Sci. Data 10, 2141–2194 (2018).

In the paper

“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.”

In the paper

“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 .”

What the sources say

• Not checked yetcites [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

In the paper

“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.”

In the paper

“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.”

What the sources say

• Not checked yetcites [21][22][23]

In the paper

“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.”

In the paper

“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 .”

What the sources say

• Not checked yetcites [50] Cui, Z. et al. Pursuing sustainable productivity with millions of smallholder farmers. Nature 555, 363–366 (2018). source

In the paper

“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 .”

What the sources say

• Not checked yetcites [48] United Nations Global Land Outlook 1st edn (United Nations Convention to Combat Desertification, 2017).

In the paper

“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 .”

What the sources say

• Not checked yetcites [32] Das, S. et al. Cropping with slag to address soil, environment, and food security. Front. Microbiol. 10, 1320 (2019). source
• Not checked yetcites [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 yetcites [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 yetcites [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

In the paper

“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.”

In the paper

“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 .”

What the sources say

• Not checked yetcites [49] Smith, M. R. & Myers, S. S. Impact of anthropogenic CO2 emissions on global human nutrition. Nat. Clim. Chang. 8, 834–839 (2018). source

In the paper

“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 .”

What the sources say

• Not checked yetcites [38] Renforth, P. The negative emission potential of alkaline materials. Nat. Commun. 10, 1401 (2019). source

In the paper

“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.”

In the paper

“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 .”

What the sources say

• Not checked yetcites [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 yetcites [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

In the paper

“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.”

In the paper

“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 .”

What the sources say

• Not checked yetcites [40] Washbourne, C.-L. et al. Rapid removal of atmospheric CO2 in urban soils. Environ. Sci. Technol. 49, 5434–5440 (2015). source
• Not checked yetcites [41] Lekakh, S. N. et al. Kinetics of aqueous leaching and carbonization of steelmaking slag. Metallurg. Mater. Trans. B 39, 125–134 (2008). source

In the paper

“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).”

What the sources say

• Not checked yetcites [6] Le Quéré, C. et al. Global carbon budget 2018. Earth Syst. Sci. Data 10, 2141–2194 (2018).

In the paper

“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 .”

What the sources say

• Not checked yetcites [51] Pidgeon, N. F. & Spence, E. Perceptions of enhanced weathering as a biological negative emissions option. Biol. Lett. 13, 20170024 (2017). source

In the paper

“At this early stage of research and development, costs are uncertain and in need of demonstration projects 7,11,12 .”

What the sources say

• Not checked yetcites [7] United Nations Environment Programme The Emissions Gap Report 2018 (United Nations Environment Programme, 2018).
• Not checked yetcites [11] The Royal Society Greenhouse Gas Removal Technologies (The Royal Society, 2018).
• Not checked yetcites [12] Pacala, S. et al. Negative Emissions Technologies And Reliable Sequestration (National Academy of Sciences, 2018).

In the paper

“The ancillary benefits of ERW may aid its early use and relieve such concern.”

In the paper

“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 .”

What the sources say

• Not checked yetcites [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 yetcites [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

In the paper

“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 .”

What the sources say

• Not checked yetcites [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

In the paper

“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.”

What the sources say

• Not checked yetcites [72] Brantley, S. L. & Mellott, N. P. Surface area and porosity of primary silicate minerals. Am. Mineral. 85, 1767–1783 (2000). source

In the paper

“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.”

In the paper

“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.”

In the paper

“Possible CO2 degassing due to changes in surface water chemistry during transport in large river systems 74 is not considered.”

What the sources say

• Not checked yetcites [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

In the paper

“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.”

In the paper

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

In the paper

“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 .”

What the sources say

• Not checked yetcites [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 yetcites [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 yetcites [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

In the paper

“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.”

In the paper

“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.”

What the sources say

• Not checked yetcites [11] The Royal Society Greenhouse Gas Removal Technologies (The Royal Society, 2018).
• Not checked yetcites [23] Fuss, S. et al. Negative emissions—Part 2: Costs, potentials and side effects. Environ. Res. Lett. 13, 063002 (2018). source

In the paper

“Their high risks of economic damage 53 and social disruption provide impetus for creative co-design of agricultural and climate policies.”

What the sources say

• Not checked yetcites [53] Ricke, K., Drout, L., Caldeira, K. & Tavoni, M. Country-level social cost of carbon. Nat. Clim. Chang. 8, 895–900 (2018). source

In the paper

“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 .”

What the sources say

• Not checked yetcites [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

In the paper

“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.”

In the paper

“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.”

In the paper

“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).”

What the sources say

• Not checked yetcites [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

In the paper

“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 .”

What the sources say

• Not checked yetcites [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 yetcites [47] Chen, J. Rapid urbanization in China: a real challenge to soil protection and food security. Catena 69, 1–15 (2007). source
• Not checked yetcites [48] United Nations Global Land Outlook 1st edn (United Nations Convention to Combat Desertification, 2017).
• Not checked yetcites [49] Smith, M. R. & Myers, S. S. Impact of anthropogenic CO2 emissions on global human nutrition. Nat. Clim. Chang. 8, 834–839 (2018). source

In the paper

“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.”

In the paper

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

In the paper

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

In the paper

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

In the paper

“The exceptions are Sb and Se.”

In the paper

“For comparison, basaltic glass powder with a diameter of 40 -120µm has a lambda 50 of ~92.”

What the sources say

• Not checked yetcites [50] Cui, Z. et al. Pursuing sustainable productivity with millions of smallholder farmers. Nature 555, 363–366 (2018). source

In the paper

“However, these are less concentrated in the unmixed cement waste 59 .”

What the sources say

• Not checked yetcites [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

In the paper

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

In the paper

“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.”