The technological and economic prospects for CO2 utilization and removal

In the paper

“Geological storage, when executed correctly, is considered to be more permanent 22 than storage in the biosphere, which is shorter and subject to human and natural disturbances 23 such as wildfires and pests, as well as changes in climate 24 .”

What the sources say

• Supported

  The Introduction reports that realistically well-regulated geological storage has a 50% probability of retaining more than 98% of injected CO2 over 10,000 years. This supports the long-term security of properly executed geological storage attributed to citation 22; the biosphere disturbances are attached to other citations. (LLM, conf=0.90)

  cites [22] Alcalde, J. et al. Estimating geological CO2 storage security to deliver on climate mitigation. Nat. Commun. 9, 2201 (2018). source
• ?Not checked — no full text of the sourcecites [23] Baccini, A. et al. Tropical forests are a net carbon source based on aboveground measurements of gain and loss. Science 358, 230–234 (2017). source
• ?Not checked — no full text of the sourcecites [24] Allen, C. D. et al. A global overview of drought and heat-induced tree mortality reveals emerging climate change risks for forests. For. Ecol. Manage. 259, 660–684 (2010). source

In the paper

“The production of plastics and other products creates a demand for so-called 'socioeconomic carbon' 19 (around 2.4 Gt CO 2 yr -1 , of which around two-thirds is wood products) that could be met in part through CO 2 utilization.”

What the sources say

• Partly supported

  The Results report 650 MtC yr⁻¹ flowing into socioeconomic stocks in 2008, equivalent to about 2.4 Gt CO₂ yr⁻¹. They put wood products at 58% of those inflows, rather than around two-thirds. The paper does not assess whether CO₂ utilization could meet this demand. (LLM, conf=0.88)

  cites [19] Lauk, C., Haberl, H., Erb, K.-H., Gingrich, S. & Krausmann, F. Global socioeconomic carbon stocks in long-lived products 1900–2008. Environ. Res. Lett. 7, 034023 (2012). sourceExperimental — accuracy not yet measured

In the paper

“However, even 'closed' pathways do not offer completely permanent storage over geological timescales (more than 100,000 years 25 ), which gives rise to intergenerational ethical questions 26 .”

What the sources say

• Partly supported

  The 'Climate impact of storage timescales' section defines geological-timescale permanent storage as securing carbon for more than 100,000 years, supporting the cited timescale. It does not say that even 'closed' pathways fail to provide storage over that period; it instead describes such storage as permanent. The intergenerational-ethics point has a separate citation in the citing sentence. (LLM, conf=0.84)

  cites [25] Scott, V., Haszeldine, R. S., Tett, S. F. B. & Oschlies, A. Fossil fuels in a trillion tonne world. Nat. Clim. Change 5, 419 (2015). sourceExperimental — accuracy not yet measured
• ?Not checked — no full text of the sourcecites [26] Gardiner, S. M. A perfect moral storm: climate change, intergenerational ethics and the problem of moral corruption. Environ. Values 15, 397–413 (2006). source

In the paper

“The total stock of carbon accumulated in products (such as wood products, bitumen, plastic and cereals) has been estimated at 42 Gt CO 2 in 2008, of which 25 Gt CO 2 is in wood products 19 .”

What the sources say

• Supported

  The Abstract reports 11.5 GtC in global socioeconomic stocks in 2008, with wood accounting for 60%. Converting carbon mass to CO₂ mass gives approximately 42 Gt CO₂ in total and 25 Gt CO₂ in wood. The Methods and data section includes wood products, bitumen, plastic and cereals in the assessment. (LLM, conf=0.93)

  cites [19] Lauk, C., Haberl, H., Erb, K.-H., Gingrich, S. & Krausmann, F. Global socioeconomic carbon stocks in long-lived products 1900–2008. Environ. Res. Lett. 7, 034023 (2012). source

In the paper

“If soil carbon uptake could be increased by 0.4% per year, this would contribute to achieving net zero emissions-as per the '4 per mille' initiative 17 -but this is challenging 18 .”

What the sources say

• Supported

  The Introduction describes the 4 per mille initiative as aspiring to increase global soil organic matter stocks by 0.4% per year to compensate for anthropogenic greenhouse-gas emissions. The Conclusions call the goal ambitious and estimate that applying it across agricultural areas could offset about 30% of global greenhouse-gas emissions, supporting the claim that it could contribute to net zero but would be challenging. (LLM, conf=0.91)

  cites [17] Minasny, B. et al. Soil carbon 4 per mille. Geoderma 292, 59–86 (2017). source
• Partly supported

  The Discussion (page unavailable) describes biophysical and economic barriers to deploying negative-emissions technologies, supporting the general point that carbon removal is challenging. But the paper says it does not evaluate soil-carbon storage, so it does not establish the specific difficulty of increasing soil carbon uptake by 0.4% per year. The ‘4 per mille’ proposition is attached to citation 17, not this source. (LLM, conf=0.82)

  cites [18] Smith, P. et al. Biophysical and economic limits to negative CO2 emissions. Nat. Clim. Change 6, 42–50 (2016). This paper quantifies potential global impacts of various negative emissions technologies in the context of biophysical resource constraints. sourceExperimental — accuracy not yet measured

In the paper

“Up to 16 Gt CO 2 was sequestered in human infrastructure as mineralized carbonates in cement between 1930 and 2013, with current rates 20,21 estimated to be around 1 Gt CO 2 yr -1 .”

What the sources say

• Supported

  Section 4.3 estimates worldwide cement-material uptake from 1930 to 2013 at 4.50 GtC, equivalent to about 16.5 Gt CO₂. Section 4.2 reports 245.15 million tons of carbon uptake in 2013, equivalent to about 0.9 Gt CO₂ per year. Both figures support the citing sentence’s rounded estimates. (LLM, conf=0.89)

  cites [20] Xi, F. et al. Substantial global carbon uptake by cement carbonation. Nat. Geosci. 9, 880–883 (2016). source
• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [21] Maries, A., Tyrer, M. & Provis, J. L. Sequestration of CO2 emissions from cement manufacture. In Proc. 37th Cement and Concrete Science Conference (eds Bai, Y. et al.) (Institute of Materials, Minerals and Mining, 2017).

In the paper

“Currently, the largest-scale chemical utilization pathway is that of urea production.140 Mt CO 2 yr -1 is utilized to produce 200 Mt yr -1 of urea 33 .”

What the sources say

• Partly supported

  Section 2.1 (Urea production; page not provided) identifies urea production as a widely implemented CO₂-utilization pathway and reports more than 190 Mt of urea produced annually, broadly consistent with 200 Mt. But it reports 112–120 Mt of CO₂ used annually, not 140 Mt; it does not establish that urea is the largest-scale chemical utilization pathway. (LLM, conf=0.88)

  cites [33] Jarvis, S. M. & Samsatli, S. Technologies and infrastructures underpinning future CO2 value chains: A comprehensive review and comparative analysis. Renew. Sustain. Energy Rev. 85, 46–68 (2018). sourceExperimental — accuracy not yet measured

In the paper

“Enhanced weathering offers a removal potential of 2 to 4 Gt CO 2 yr -1 at costs 28 of around $200 per tonne of CO 2 .”

What the sources say

• Partly supported

  Section 3.4 gives a removal potential of 2–4 GtCO₂ per year, but specifies that it is from 2050 and excludes biological storage. It gives a cost range of US$50–200 per tonne, so the claimed ‘around $200’ presents the upper end as though it were the general cost. No page number is provided in our copy. (LLM, conf=0.86)

  cites [28] Fuss, S. et al. Negative emissions—Part 2: Costs, potentials and side effects. Environ. Res. Lett. 13, 063002 (2018). This paper estimates—through a large scoping review—that afforestation and reforestation, BECCS, biochar, enhanced weathering, DACCS and soil carbon sequestration all have multi-gigatonne sequestration potentials in 2050, and that costs vary widely. sourceExperimental — accuracy not yet measured

In the paper

“The utilization of CO 2 in wood products will occur in addition to the direct removal of CO 2 by forests under certain highly specific circumstances; sustainable harvesting can maintain carbon stocks in forests while providing a source of renewable biomass 58,59 .”

What the sources say

• ?Not checked — no full text of the sourcecites [58] Pingoud, K., Ekholm, T., Sievänen, R., Huuskonen, S. & Hynynen, J. Trade-offs between forest carbon stocks and harvests in a steady state – a multi-criteria analysis. J. Environ. Manage. 210, 96–103 (2018). source
• Supported

  The paper’s Forest management section says that when wood removals do not exceed net growth, forest carbon remains stable across the managed landscape. Its Life cycle forest, product & integrated processing energy carbon pools section says harvested wood extends forest carbon storage into products. This supports the claim under sustainable-management conditions; individual stands can temporarily lose carbon at harvest. (LLM, conf=0.90)

  cites [59] Lippke, B. et al. Life cycle impacts of forest management and wood utilization on carbon mitigation: knowns and unknowns. Carbon Manage. 2, 303–333 (2011). source

In the paper

“Up to 3 tonnes of CO 2 emissions may be avoided for every 1 tonne of CO 2 used in polycarbonate polyols 2 , even though no CO 2 is removed from atmosphere.”

What the sources say

• Supported

  The Conclusions report that up to three kg CO₂-equivalent emissions are avoided per kg CO₂ incorporated into polyols, while the polyols are not a net greenhouse-gas sink. Section 2.2 identifies the CO₂ source as captured power-plant flue gas, not atmospheric removal. The three-to-one figure applies to polyols with 30 wt% CO₂. (LLM, conf=0.91)

  cites [2] von der Assen, N. & Bardow, A. Life cycle assessment of polyols for polyurethane production using CO2 as feedstock: insights from an industrial case study. Green Chem. 16, 3272–3280 (2014). source

In the paper

“Similarly, a robust finding in the literature on integrated-assessment modelling is that the electricity sector should be decarbonized first, which then facilitates decarbonization in other, more difficult sectors 77 .”

What the sources say

• Supported

  The Energy supply section reports that electricity offers large, low-cost emissions reductions and becomes virtually carbon-free by 2050 in the stringent modelled pathways. The Demand-side transformation section explains that rapid power-supply decarbonization makes electrification of end uses an increasingly powerful mitigation option, while noting that electrification is harder in sectors such as transport. Together, these passages support the claimed sequencing and its role in decarbonizing other sectors. (LLM, conf=0.86)

  cites [77] Luderer, G. et al. Residual fossil CO2 emissions in 1.5–2 °C pathways. Nat. Clim. Change 8, 626–633 (2018). source

In the paper

“Given the rapid rate at which human societies are urbanizing 82 , there is an urgent one-time opportunity to deploy new building materialsincluding wood, as discussed below-that utilize and store CO 2 and displace emissions-intensive Portland cement.”

What the sources say

• Supported

  The citation is attached to the rapid rate of urbanization, not the subsequent proposal to use wood or replace cement. The Abstract forecasts that urban land cover could nearly triple by 2030, and the Discussion says 65% of urban land in 2030 would have become urban during the preceding three decades. (LLM, conf=0.93)

  cites [82] Seto, K. C., Güneralp, B. & Hutyra, L. R. Global forecasts of urban expansion to 2030 and direct impacts on biodiversity and carbon pools. Proc. Natl Acad. Sci. USA 109, 16083–16088 (2012). source

In the paper

“Catalytic processes can be optimized to increase CO 2 emission reductions or to reduce energy consumption 81 .”

What the sources say

• Supported

  The Introduction says advances in catalyst efficiency can yield gains in energy consumption and CO2 emissions for particular fuel-production and conversion processes. Section 4.2 identifies processes where improving catalyst efficiency can reduce total energy use or CO2 emissions, supporting the claim's qualified 'can.' (LLM, conf=0.92)

  cites [81] Xiao, T. et al. The Catalyst Selectivity Index (CSI): a framework and metric to assess the impact of catalyst efficiency enhancements upon energy and CO2 footprints. Top. Catal. 58, 682–695 (2015). source

In the paper

“Production of 'green' hydrogen-by the electrolysis of water-has real potential, and the ultimate choice of technology for the generation of hydrogen will depend on the rates of cost reduction 69 , among other factors.”

What the sources say

• Partly supported

  The “AWE Cost Literature Overview” (page unavailable) describes potential future cost decreases from technological development and learning, supporting the relevance of cost reduction to water electrolysis. The paper analyzes alkaline water electrolysis, however, and does not say that the ultimate choice among hydrogen-generation technologies will depend on their rates of cost reduction. (LLM, conf=0.84)

  cites [69] Kuckshinrichs, W., Ketelaer, T. & Koj, J. C. Economic analysis of improved alkaline water electrolysis. Front. Energy Res. 5, 1 (2017). sourceExperimental — accuracy not yet measured

In the paper

“A better understanding of soil carbon dynamics and improved phenotypic and genotypic plant selection will also help 85 .”

What the sources say

• Partly supported

  The Conclusion (page unavailable) calls for better estimates and understanding of soil organic carbon dynamics. The cited paper does not address improved phenotypic or genotypic plant selection, so that part of the claim is unsupported. (LLM, conf=0.86)

  cites [85] Scharlemann, J. P. W., Tanner, E. V. J., Hiederer, R. & Kapos, V. Global soil carbon: understanding and managing the largest terrestrial carbon pool. Carbon Manage. 5, 81–91 (2014). sourceExperimental — accuracy not yet measured

In the paper

“Specification, quality and safety measures for these products are approaching comparability to many concrete structures 88 , and current manufacturing scale-up suggests that this may be a market with strong growth prospects.”

What the sources say

• Partly supported

  The citation follows the claim about specifications, quality and safety, not the later market-growth inference. Section 5.3 (page unavailable) describes grading, product standards and improved properties of engineered timber; Section 7 says common European standards enable larger timber buildings. But Section 8.1 identifies distinct fire-safety challenges, and the paper does not establish that these measures are approaching comparability with those for concrete structures. (LLM, conf=0.83)

  cites [88] Ramage, M. H. et al. The wood from the trees: The use of timber in construction. Renew. Sustain. Energy Rev. 68, 333–359 (2017). sourceExperimental — accuracy not yet measured

In the paper

“Some carbon capture and utilization (CCU) processes achieve carbon dioxide removal (CDR) from the atmosphere, and some involve CCS.”

In the paper

“CO 2 can be transformed efficiently into a range of chemicals, but only a few of the technologies are economically viable and scalable.”

In the paper

“However, only 2%-3% of this photosynthetic carbon remains on land (12 Gt CO 2 yr -1 ), and only for decades; the remainder is re-emitted by plant and soil respiration.”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [16] IPCC Climate Change 2014: Mitigation of Climate Change (eds. Edenhofer, O. et al.) (Cambridge Univ. Press, 2014).

In the paper

“Within days of being applied as fertilizer, the carbon in urea is released to the atmosphere.”

In the paper

“The US Department of Energy's target for the cost of hydrogen production-$2 per kg of H 2 -is roughly equivalent to $2 per gasoline-gallon equivalent, and would require carbon-free electricity to cost less than $0.03 kWh -1 (accounting for kinetics and other losses to the enthalpy of electrolysis-based hydrogen production, around 40 kWh per kg H 2 ) 40 .”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [40] Secretary of Energy Advisory Board. Letter Report: Task Force on RD&D Strategy for CO 2 Utilization and/or Negative Emissions at the Gigatonne Scale. (US Department of Energy, 2016).

In the paper

“A CO 2 -to-methanol plant operates in Iceland, and various power-togas plants operate worldwide.”

In the paper

“The estimated utilization potential for CO 2 in chemicals is around 0.3 to 0.6 Gt CO 2 yr -1 in 2050, and the interquartile range of breakeven costs obtained from the scoping review is -$80 to $320 per tonne of CO 2 .”

In the paper

“CO 2 utilization pathways in concrete building materials are estimated to remove, utilize and store between 0.1 and 1.4 Gt CO 2 yr -1 over the long term-with the CO 2 sequestered well beyond the lifespan of the infrastructure itself”

In the paper

“The breakeven costs per tonne of CO 2 utilized that we estimate here are low and are frequently negative.”

In the paper

“The microalgae pathway has complex production economics and the estimated CO 2 utilization potential for microalgae in 2050 ranges from 0.2 to 0.9 Gt CO 2 yr -1 , with a breakeven cost interquartile range from the scoping review of $230 to $920 per tonne of CO 2 .”

In the paper

“Biochar is currently at a low TRL and has associated uncertainties.”

In the paper

“| Microalgae | 2,680 | 1,000 | +170% | Likely to be more expensive | Insufficient consensus |”

In the paper

“Figures 1 and 3 suggest that land-based biological processes offer a large opportunity to utilize, remove and store more CO 2 .”

In the paper

“Pathways that involve chemicals, fuels and microalgae might reduce emissions of carbon dioxide but have limited potential for its removal, whereas pathways that involve construction materials can both utilize and remove carbon dioxide.”

In the paper

“rapid cost-reductions could potentially occur if renewable energy-which represents a large proportion of total cost-continues to become cheaper, and if policy stimulates other cost reductions.”

In the paper

“The low end-which is itself considerable-represents very modest penetration into the methane and fuels markets, but it could also be an overestimate if CO 2 -derived products do not become costcompetitive with alternative clean energy vectors such as hydrogen or ammonia, or with direct sequestration.”

In the paper

“All nitrogen-based fertilizers produce N 2 O, a greenhouse gas that is around 300 times more potent than CO 2 over a 100-year time horizon 34 .”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [34] Myhre, G. et al. In Climate Change 2013: The Physical Science Basis (eds Stocker, T. F. et al.) 659–740 (IPCC, Cambridge Univ. Press, 2013).

In the paper

“The long-term use of carbonbased energy carriers in a net zero emissions economy relies upon their production with renewable energy, and upon low-cost, scalable, clean hydrogen production-for example via the electrolysis of water or by novel alternative methods.”

In the paper

“CO 2 utilization does not necessarily reduce emissions and does not necessarily deliver a net climate benefit, once indirect and other effects have been accounted for.”

In the paper

“In the longer term, the CO 2 loop will need to be closed in order to achieve net zero emissions, implying that CO 2 will need to be sourced from the atmosphere, potentially via direct air capture (A) or through land-based uptake by photosynthesis or mineralization (B).”

In the paper

“CCS itself can contribute either to the mitigation of CO 2 (for example, by reducing net emissions from a gas-fired power plant) or to atmospheric removals (for example, by direct air carbon capture and storage, or DACCS); CCS does not necessarily imply CDR.”

In the paper

“Fuels derived from CO 2 are argued to be an attractive option in the decarbonization process 37,38 because they can be deployed within existing transport infrastructure.”

What the sources say

• ?Not checked — no full text of the sourcecites [37] Jiang, Z., Xiao, T., Kuznetsov, V. L. & Edwards, P. P. Turning carbon dioxide into fuel. Philos. Trans. A 368, 3343–3364 (2010). source
• ?Not checked — no full text of the sourcecites [38] Olah, G. A. Beyond oil and gas: the methanol economy. Angew. Chem. Int. Ed. 44, 2636–2639 (2005). source

In the paper

“The other five conventional industrial CO 2 utilization pathways could also perturb the net flows of CO 2 .”

In the paper

“Land-based pathways can increase agricultural output and remove carbon dioxide.”

In the paper

“The high end represents a future in which synfuels have sizeable market shares, due to cost reductions and policy drivers.”

In the paper

“If CO 2 -EOR is to offer net removals, the CO 2 must be captured from the atmosphere, and more carbon must be injected into the well than is extracted.”

In the paper

“Emissions have been reduced, and CO 2 ρ = CO 2 u = CO 2 s > 0, even though CO 2 r = 0.”

In the paper

“Microalgae are a subject of long-standing research interest because of their high CO 2 -fixation efficiencies (up to 10%, compared with 1%-4% for other biomass 45 ), as well as their potential to produce a range of products such as biofuels, high-value carbohydrates and proteins, and plastics 43 .”

What the sources say

• ?Not checked — no full text of the sourcecites [45] Williams, P. J. B. & Laurens, L. M. Microalgae as biodiesel & biomass feedstocks: review & analysis of the biochemistry, energetics & economics. Energy Environ. Sci. 3, 554–590 (2010). source
• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [43] Laurens, L. M. L. State of Technology Review – Algae Bioenergy (IEA Bioenergy, 2017).

In the paper

“Total emissions in this 'utilization' scenario comprise the 1.5 t CO 2 from the consumption of the CO 2 -EOR oil.Emissions reduced is equal to 2.5 -1.5 = 1.0 t CO 2 ρ, which is identical to the CO 2 u, but net CO 2 r = 0 because the CO 2 came from a fossil power plant, rather than from the atmosphere.”

In the paper

“This is particularly relevant for the algal pathways thatrequire photobioreactors 43 and for the fuel synthesis pathways that require electrolysers 44 .”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [43] Laurens, L. M. L. State of Technology Review – Algae Bioenergy (IEA Bioenergy, 2017).
• ?Not checked — no full text of the sourcecites [44] Brynolf, S., Taljegard, M., Grahn, M. & Hansson, J. Electrofuels for the transport sector: A review of production costs. Renew. Sustain. Energy Rev. 81, 1887–1907 (2018). source

In the paper

“At oil prices of approximately $100 bbl -1 , EOR is economically viable if CO 2 can be sourced for between $45 and $60 per tonne of CO 2 49,51 , implying a breakeven cost of CO 2 of -$60 to -$45 per tonne of CO 2 .”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [49] Heidug, W. et al. Storing CO 2 through enhanced oil recovery: combining EOR with CO 2 storage (EOR+) for profit. (International Energy Agency, 2015).
• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [51] Godec, M. L. Global Technology Roadmap for CCS in Industry: Sectoral Assessment CO 2 Enhanced Oil Recovery. (United Nations Industrial Development Organization, 2011).

In the paper

“Assuming that the CO 2 does not return to atmosphere, the CO 2 utilized is equal to the CO 2 emissions stored, that is, CO 2 u = CO 2 s, but whether CO 2 r ≥ 0 depends upon the source of the CO 2 ; if it is from a fossil power station, there is no net removal of CO 2 from the atmosphere.”

In the paper

“It might reduce emissions (CO 2 ρ), or remove CO 2 (CO 2 r) from the atmosphere, and/or store it (CO 2 s).”

In the paper

“Enhanced oil recovery using CO 2 currently accounts for around 5% of the total US crude oil production 48 .”

What the sources say

• ?Not checked — no full text of the sourcecites [48] Dai, Z. et al. CO2 accounting and risk analysis for CO2 sequestration at enhanced oil recovery sites. Environ. Sci. Technol. 50, 7546–7554 (2016). source

In the paper

“However, under our broad definition, there may still be an as-yet-unquantified CO 2 utilization potential associated with the increase in net primary productivity.”

In the paper

“Although there is substantial uncertainty regarding the total quantity of available biomass 55 -particularly in light of concerns over competition for land use with food crops-100 to 300 EJ yr -1 of primary energy equivalent of biomass could be deployed by 2050.”

What the sources say

• ?Not checked — no full text of the sourcecites [55] Slade, R., Bauen, A. & Gross, R. Global bioenergy resources. Nat. Clim. Change 4, 99 (2014). source

In the paper

“These cost estimates (realistically or unrealistically) assume $100 bbl -1 oil prices and are specific to the United States, where the business model is mature.”

In the paper

“New membrane materials that can separate miscible liquidsfor example, methanol and water-will also be important 80 .”

What the sources say

• ?Not checked — no full text of the sourcecites [80] Mahmood, A., Bano, S., Kim, S.-G. & Lee, K.-H. Water–methanol separation characteristics of annealed SA/PVA complex membranes. J. Membr. Sci. 415–416, 360–367 (2012). source

In the paper

“CO 2 -EOR utilizes and, with correct policy, stores CO 2 at scale, but may not yield any net climate benefit and may even be detrimental.”

In the paper

“The cost of DACCS has recently been assessed to be between $600 and $1,000 per tonne of CO 2 for the first-of-a-kind plant, with nth-of-a-kind costs potentially of the order of $200 per tonne of CO 2 79 .”

What the sources say

• ?Not checked — no full text of the sourcecites [79] Keith, D. W., Holmes, G., St., Angelo, D. & Heidel, K. A process for capturing CO2 from the atmosphere. Joule 2, 1573–1594 (2018). source

In the paper

“These curves are constructed using currently available (and often sparse) data in the peer-reviewed literature, or-where data are not available-using approximations, and should be considered as a speculative first pass at envisioning future scenarios.”

In the paper

“For instance, the putative success of CO 2 -fuels may reduce the demand for oil, thus also reducing the potential of CO 2 -EOR.”

In the paper

“Building materials face a challenging route to market penetration owing to regulatory barriers, which may take decades to surmount.”

In the paper

“The chemicals pathways may reduce net emissions by displacing fossil fuel use, but will not contribute to net removal unless they are paired with direct air capture in a net zero world.”

In the paper

“Although market penetration can be facilitated by cost-competitiveness, there is no certainty that the cheapest CO 2 utilization pathways will scale up.”

In the paper

“At present, 'brown' hydrogen is primarilyand most cheaply-generated by reforming methane 68 , which has associated CO 2 emissions.”

What the sources say

• ?Not checked — no full text of the sourcecites [68] Izquierdo, U. et al. Hydrogen production from methane and natural gas steam reforming in conventional and microreactor reaction systems. Int. J. Hydrogen Energy 37, 7026–7033 (2012). source

In the paper

“The curves should not be interpreted as comprehensive assessments of costs, they do not represent nth-ofa-kind costs, and they are incompatible with other sequestration or abatement cost curves.”

In the paper

“Many technologies are in the very early stages of development, and cost optimization via research and development could substantially change these estimates.”

In the paper

“In a decarbonized world, those supply-chain emissions will be close to zero and so the climate benefit from BECCS will be amplified.”

In the paper

“Because they are based on a backward-looking scoping review, our cost estimates for conventional pathways do not capture current unpublished innovations and advances in the industrial arena.”

In the paper

“Land management, biochar and forestry offer only shorterterm storage, face saturation, and risk large-scale flows of CO 2 back to the atmosphere 23 .”

What the sources say

• ?Not checked — no full text of the sourcecites [23] Baccini, A. et al. Tropical forests are a net carbon source based on aboveground measurements of gain and loss. Science 358, 230–234 (2017). source

In the paper

“Although photosynthesis is an inefficient process (the average efficiency is around 0.2% globally 67 )”

What the sources say

• ?Not checked — no full text of the sourcecites [67] Barber, J. Photosynthetic energy conversion: natural and artificial. Chem. Soc. Rev. 38, 185–196 (2009). source

In the paper

“Open pathways, although both theoretically profitable and implementable, often incur additional operating costs-such as implementation, transaction, institutional, and monitoring costs-which can be high 71 .”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [71] Viana, V. M., Grieg-Gran, M., Della Mea, R. & Ribenboim, G. The Costs of REDD: Lessons From Amazonas (International Institute for Environment and Development, 2009).

In the paper

“The uncertainty in future outcomes is relatively large, and very few industries globally involve over 1 Gt yr -1 of material flows.”

In the paper

“CO 2 utilization is not an end in itself, and these pathways solely or even collectively will not provide a key solution to climate change.”

In the paper

“Financing and managing the emergence of a globally important new set of CO 2 utilization industries will probably require clear direction and industrial support from government.”

In the paper

“However, if these can be overcome, its position low on the cost curve in both low and high scenarios suggests that this pathway may have considerable potential.”

In the paper

“An enabling 'net zero' legislative regime-such as that in place in Sweden and the UK and proposed in New Zealand-can provide clarity about the necessary scale of industries that reduce and remove CO 2 , including the pathways examined here.”

In the paper

“Instead, incentives for CO 2 removals and reductions (or penalties for emissions) are justified, and these will support CO 2 utilization in cases in which it is beneficial for the climate.”

In the paper

“creating carbon prices of around $40 to $80 per tonne of CO 2 -increasing over time-to penalize CO 2 emissions 89 and to incentivize verifiable CO 2 emissions reductions and removals from the atmosphere.”

What the sources say

• ?Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

  cites [89] High-Level Commission on Carbon Prices Report of the High-Level Commission on Carbon Prices (World Bank, 2017).