Carbon dioxide removal: Difference between revisions

Content deleted Content added

Inline

Revision as of 18:04, 30 May 2022

Carbon dioxide removal (CDR), also known as negative CO₂ emissions, is a process in which carbon dioxide gas (CO₂) is removed from the atmosphere and sequestered for long periods of time.^[1]^[2]^[3] Similarly, greenhouse gas removal (GGR) or negative greenhouse gas emissions is the removal of greenhouse gases (GHGs) from the atmosphere by deliberate human activities, i.e., in addition to the removal that would occur via natural carbon cycle or atmospheric chemistry processes.^[4] In the context of net zero greenhouse gas emissions targets,^[5] CDR is increasingly integrated into climate policy, as a new element of mitigation strategies.^[6] CDR and GGR methods are also known as negative emissions technologies (NET), and may be cheaper than preventing some agricultural greenhouse gas emissions.^[7]

CDR methods include afforestation, agricultural practices that sequester carbon in soils, bio-energy with carbon capture and storage, ocean fertilization, enhanced weathering, and direct air capture when combined with storage.^[2]^[8]^[9] To assess whether net negative emissions are achieved by a particular process, comprehensive life cycle analysis of the process must be performed.

A 2019 consensus report by the US National Academies of Sciences, Engineering, and Medicine (NASEM) concluded that using existing CDR methods at scales that can be safely and economically deployed, there is potential to remove and sequester up to 10 gigatons of carbon dioxide per year.^[7] This would offset greenhouse gas emissions at about a fifth of the rate at which they are being produced.

In 2021 the Intergovernmental Panel on Climate Change (IPCC) said that emission pathways that limit globally averaged warming to 1.5 °C or 2 °C by the year 2100 assume the use of CDR approaches in combination with emission reductions.^[10]^[11]

Definitions

The Intergovernmental Panel on Climate Change defines CDR as:

Anthropogenic activities removing CO₂ from the atmosphere and durably storing it in geological, terrestrial, or ocean reservoirs, or in products. It includes existing and potential anthropogenic enhancement of biological or geochemical sinks and direct air capture and storage, but excludes natural CO₂ uptake not directly caused by human activities.^[1]

The U.S.-based National Academies of Sciences, Engineering, and Medicine uses the term "negative emissions technology" with a similar definition.^[7]

The concept of deliberately reducing the amount of CO₂ in the atmosphere is often mistakenly classified with solar radiation management as a form of climate engineering^{[contradictory]} and assumed to be intrinsically risky.^[7]^{[need quotation to verify]} In fact, CDR addresses the root cause of climate change and is part of strategies to reduce net emissions and manage risks related to elevated atmospheric CO₂ levels.^[2]^[12]

Concepts using similar terminology

CDR can be confused with carbon capture and storage (CCS), a process in which carbon dioxide is collected from point-sources such as gas-fired power plants, whose smokestacks emit CO₂ in a concentrated stream. The CO₂ is then compressed and sequestered or utilized.^[1] When used to sequester the carbon from a gas-fired power plant, CCS reduces emissions from continued use of the point source, but does not reduce the amount of carbon dioxide already in the atmosphere.

Potential for climate change mitigation

The likely need for CDR (carbon dioxide removal) has been publicly expressed by a range of individuals and organizations involved with climate change issues, including IPCC chief Dr. Hoesung Lee,^[13] the UNFCCC executive secretary Christiana Figueres,^[14] and the World Watch Institute.^[15] Institutions with major programs focusing on CDR include the Lenfest Center for Sustainable Energy at the Earth Institute, Columbia University,^[16] and the Climate Decision Making Center,^[17] an international collaboration operated out of Carnegie-Mellon University's Department of Engineering and Public Policy.

Using CDR in parallel with other efforts to reduce greenhouse gas emissions, such as deploying renewable energy, is likely to be less expensive and disruptive than using other efforts alone.^[7] A 2019 consensus study report by NASEM assessed the potential of all forms of CDR other than ocean fertilization that could be deployed safely and economically using current technologies, and estimated that they could remove up to 10 gigatons of CO₂ per year if fully deployed worldwide.^[7] This is one-fifth of the 50 gigatons of CO₂ emitted per year by human activities.^[7] In the IPCC's 2018 analysis of ways to limit climate change, all analyzed mitigation pathways that would prevent more than 1.5 °C of warming included CDR measures.^[18]

Some mitigation pathways propose achieving higher rates of CDR through massive deployment of one technology, however these pathways assume that hundreds of millions of hectares of cropland are converted to growing biofuel crops.^[7] Further research in the areas of direct air capture, geologic sequestration of carbon dioxide, and carbon mineralization could potentially yield technological advancements that make higher rates of CDR economically feasible.^[7]

The IPCC's 2018 report said that reliance on large-scale deployment of CDR would be a "major risk" to achieving the goal of less than 1.5 °C of warming, given the uncertainties in how quickly CDR can be deployed at scale.^[18] Strategies for mitigating climate change that rely less on CDR and more on sustainable use of energy carry less of this risk.^[18]^[19] The possibility of large-scale future CDR deployment has been described as a moral hazard, as it could lead to a reduction in near-term efforts to mitigate climate change.^[20]^[7] The 2019 NASEM report concludes:

Any argument to delay mitigation efforts because NETs will provide a backstop drastically misrepresents their current capacities and the likely pace of research progress.^[7]

Methods

Afforestation, reforestation, and forestry management

According to the International Union for Conservation of Nature: "Halting the loss and degradation of natural systems and promoting their restoration have the potential to contribute over one-third of the total climate change mitigation scientists say is required by 2030."^[21]

Forests are vital for human society, animals and plant species. This is because trees keep air clean, regulate the local climate and provide a habitat for numerous species. Trees and plants convert carbon dioxide back into oxygen, using photosynthesis. They are important for regulating CO₂ levels in the air, as they remove and store carbon from the air. Without them, the atmosphere would heat up quickly and destabilise the climate.^[22]

Increased use of wood in construction is being considered.^[23]

Carbon sequestration

Carbon sequestration is the process of storing carbon in a carbon pool.^[24]^: 2248 It plays a crucial role in limiting climate change by reducing the amount of carbon dioxide in the atmosphere. There are two main types of carbon sequestration: biologic (also called biosequestration) and geologic.^[25]

Biologic carbon sequestration is a naturally occurring process as part of the carbon cycle. Humans can enhance it through deliberate actions and use of technology. Carbon dioxide (CO
₂) is naturally captured from the atmosphere through biological, chemical, and physical processes. These processes can be accelerated for example through changes in land use and agricultural practices, called carbon farming. Artificial processes have also been devised to produce similar effects. This approach is called carbon capture and storage. It involves using technology to capture and sequester (store) CO
₂ that is produced from human activities underground or under the sea bed.

Biosequestration

Biosequestration is the capture and storage of the atmospheric greenhouse gas carbon dioxide by continual or enhanced biological processes. This form of carbon sequestration occurs through increased rates of photosynthesis via land-use practices such as reforestation, sustainable forest management, and genetic engineering. The SALK Harnessing Plants Initiative led by Joanne Chory is an example of an enhanced photosynthesis initiative^[26]^[27] Carbon sequestration through biological processes affects the global carbon cycle.

Agricultural practices

Carbon farming is a set of agricultural methods that aim to store carbon in the soil, crop roots, wood and leaves. The technical term for this is carbon sequestration. The overall goal of carbon farming is to create a net loss of carbon from the atmosphere.^[28] This is done by increasing the rate at which carbon is sequestered into soil and plant material. One option is to increase the soil's organic matter content. This can also aid plant growth, improve soil water retention capacity^[29] and reduce fertilizer use.^[30] Sustainable forest management is another tool that is used in carbon farming.^[31] Carbon farming is one component of climate-smart agriculture. It is also one way to remove carbon dioxide from the atmisphere.

Agricultural methods for carbon farming include adjusting how tillage and livestock grazing is done, using organic mulch or compost, working with biochar and terra preta, and changing the crop types. Methods used in forestry include reforestation and bamboo farming.

Carbon farming methods might have additional costs. Some countries have government policies that give financial incentives to farmers to use carbon farming methods.^[32] As of 2016, variants of carbon farming reached hundreds of millions of hectares globally, of the nearly 5 billion hectares (1.2×10¹⁰ acres) of world farmland.^[33] Carbon farming is not without its challenges or disadvantages. This is because some of its methods can affect ecosystem services. For example, carbon farming could cause an increase of land clearing, monocultures and biodiversity loss.^[34] It is important to maximize environmental benefits of carbon farming by keeping in mind ecosystem services at the same time.^[34]

Wetland restoration

Blue carbon is a concept within climate change mitigation that refers to "biologically driven carbon fluxes and storage in marine systems that are amenable to management".^[36]^: 2220 Most commonly, it refers to the role that tidal marshes, mangroves and seagrasses can play in carbon sequestration.^[36]^: 2220 These ecosystems can play an important role for climate change mitigation and ecosystem-based adaptation. However, when blue carbon ecosystems are degraded or lost, they release carbon back to the atmosphere, thereby adding to greenhouse gas emissions.^[36]^: 2220

The methods for blue carbon management fall into the category of "ocean-based biological carbon dioxide removal (CDR) methods".^[37]^: 764 They are a type of biological carbon fixation.

Scientists are looking for ways to further develop the blue carbon potential of ecosystems.^[38] However, the long-term effectiveness of blue carbon as a carbon dioxide removal solution is under debate.^[39]^[38]^[40]

The term deep blue carbon is also in use and refers to storing carbon in the deep ocean waters.^[41]

Bioenergy with carbon capture & storage

Bioenergy with carbon capture and storage (BECCS) is the process of extracting bioenergy from biomass and capturing and storing the carbon, thereby removing it from the atmosphere.^[42] BECCS can theoretically be a "negative emissions technology" (NET),^[43] although its deployment at the scale considered by many governments and industries can "also pose major economic, technological, and social feasibility challenges; threaten food security and human rights; and risk overstepping multiple planetary boundaries, with potentially irreversible consequences".^[44] The carbon in the biomass comes from the greenhouse gas carbon dioxide (CO₂) which is extracted from the atmosphere by the biomass when it grows. Energy ("bioenergy") is extracted in useful forms (electricity, heat, biofuels, etc.) as the biomass is utilized through combustion, fermentation, pyrolysis or other conversion methods.

Some of the carbon in the biomass is converted to CO₂ or biochar which can then be stored by geologic sequestration or land application, respectively, enabling carbon dioxide removal (CDR).^[43]

The potential range of negative emissions from BECCS was estimated to be zero to 22 giga tonnes per year.^[45] As of 2019, five facilities around the world were actively using BECCS technologies and were capturing approximately 1.5 million tonnes per year of CO₂.^[46] Wide deployment of BECCS is constrained by cost and availability of biomass.^[47]^[48]^: 10

Biochar

Biochar is created by the pyrolysis of biomass, and is under investigation as a method of carbon sequestration. Biochar is a charcoal that is used for agricultural purposes which also aids in carbon sequestration, the capture or hold of carbon. It is created using a process called pyrolysis, which is basically the act of high temperature heating biomass in an environment with low oxygen levels. What remains is a material known as char, similar to charcoal but is made through a sustainable process, thus the use of biomass.^[49] Biomass is organic matter produced by living organisms or recently living organisms, most commonly plants or plant based material.^[50] A study done by the UK Biochar Research Center has stated that, on a conservative level, biochar can store 1 gigaton of carbon per year. With greater effort in marketing and acceptance of biochar, the benefit could be the storage of 5–9 gigatons per year of carbon in biochar soils.^[51]^{[better source needed]}

Enhanced weathering

Enhanced weathering is a chemical approach to remove carbon dioxide involving land- or ocean-based techniques. One example of a land-based enhanced weathering technique is in-situ carbonation of silicates. Ultramafic rock, for example, has the potential to store from hundreds to thousands of years' worth of CO₂ emissions, according to estimates.^[52]^[53] Ocean-based techniques involve alkalinity enhancement, such as grinding, dispersing, and dissolving olivine, limestone, silicates, or calcium hydroxide to address ocean acidification and CO₂ sequestration.^[54] One example of a research project on the feasibility of enhanced weathering is the CarbFix project in Iceland.^[55]^[56]^[57]

Direct air capture

Direct air capture (DAC) is the use of chemical or physical processes to extract carbon dioxide directly from the ambient air.^[59] If the extracted CO₂ is then sequestered in safe long-term storage (called direct air carbon capture and sequestration (DACCS)), the overall process will achieve carbon dioxide removal and be a "negative emissions technology" (NET).

The carbon dioxide (CO₂) is captured directly from the ambient air; this is contrast to carbon capture and storage (CCS) which captures CO₂ from point sources, such as a cement factory or a bioenergy plant.^[60] After the capture, DAC generates a concentrated stream of CO₂ for sequestration or utilization or production of carbon-neutral fuel. Carbon dioxide removal is achieved when ambient air makes contact with chemical media, typically an aqueous alkaline solvent^[61] or sorbents.^[62] These chemical media are subsequently stripped of CO₂ through the application of energy (namely heat), resulting in a CO₂ stream that can undergo dehydration and compression, while simultaneously regenerating the chemical media for reuse.

When combined with long-term storage of CO₂, DAC is known as direct air carbon capture and storage (DACCS or DACS^[63]). It would require sustainable energy to power since approximately 400kJ of energy is needed per mole of CO₂ capture. DACCS can act as a carbon dioxide removal mechanism (or a carbon negative technology), although as of 2023^[update] it has yet to be integrated into emissions trading because, at over US$1000,^[64] the cost per tonne of carbon dioxide is many times the carbon price on those markets.^[65]

DAC was suggested in 1999 and is still in development.^[66]^[67] Several commercial plants are planned or in operation in Europe and the US. Large-scale DAC deployment may be accelerated when connected with economical applications or policy incentives.

In contrast to carbon capture and storage (CCS) which captures emissions from a point source such as a factory, DAC reduces the carbon dioxide concentration in the atmosphere as a whole. Thus, CCS is recommended for large and stationary sources of CO₂ rather than distributed and movable ones. On the contrary, DAC has no limitation on sources.^[60]

Magnesium silicate/oxide in cement

Lifecycle amounts are not yet fully understood.^[23]

Issues

Economic issues

The cost of CDR differs substantially depending on the maturity of the technology employed as well as the economics of both voluntary carbon removal markets and the physical output; for example, the pyrolysis of biomass produces biochar that has various commercial applications, including soil regeneration and wastewater treatment.^[68] In 2021 DAC cost from $250 to $600 per ton, compared to $100 for biochar and less than $50 for nature-based solutions, such as reforestation and afforestation.^[69]^[70] The fact that biochar commands a higher price in the carbon removal market than nature-based solutions reflects the fact that it is a more durable sink with carbon being sequestered for hundreds or even thousands of years while nature-based solutions represent a more volatile form of storage, which risks related to forest fires, pests, economic pressures and changing political priorities.^[71] The Oxford Principles for Net Zero Aligned Carbon Offsetting states that to be compatible with the Paris Agreement: “…organizations must commit to gradually increase the percentage of carbon removal offsets they procure with the view of exclusively sourcing carbon removals by mid-century.”^[72] These initiatives along with the development of new industry standards for engineered carbon removal, such as the Puro Standard, will help to support the growth of the carbon removal market.^[73]

In 2021, businessman Elon Musk announced he was donating $100m for a prize for best carbon capture technology.^[74]

Although CDR is not covered by the EU Allowance as of 2021, the European Commission is preparing for carbon removal certification and considering carbon contracts for difference.^[75]^[76] CDR might also in future be added to the UK Emissions Trading Scheme.^[23] As of end 2021 carbon prices for both these cap-and-trade schemes currently based on carbon reductions, as opposed to carbon removals, remained below $100.^[77]^[78]

In April 2022, a private sector aliance led by Stripe with prominent members including Meta, Google and Shopify, revealed a nearly $1 billion dollar fund to reward companies able to permanently capture & store carbon. According to senior Stripe employee Nan Ransohoff, the new fund "is roughly 30 times the carbon-removal market that existed in 2021. But it’s still 1,000 times short of the market we need by 2050.” ^[79]

Removal of other greenhouse gases

Although some researchers have suggested methods for removing methane, others say that nitrous oxide would be a better subject for research due to its longer lifetime in the atmosphere.^[80]

Bibliography

IPCC, 2018: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [V. Masson-Delmotte, P. Zhai, H. O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J. B. R. Matthews, Y. Chen, X. Zhou, M. I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, T. Waterfield (eds.)].
- Report website, chapters I–V
- Summary for policymakers, 32 pp.
- Headline statements, 2 pp.
- Technical summary, 22 pp.
- FAQ, 24 pp.
- Glossary, 24 pp.

References

^ ^a ^b ^c Intergovernmental Panel on Climate Change. "Glossary — Global Warming of 1.5 ºC". Archived from the original on December 22, 2019. Retrieved February 23, 2020.
^ ^a ^b ^c "Geoengineering the climate: science, governance and uncertainty". The Royal Society. 2009. Archived from the original on October 23, 2019. Retrieved September 10, 2011.
^ Minx, Jan C; Lamb, William F; Callaghan, Max W; Fuss, Sabine; Hilaire, Jérôme; Creutzig, Felix; Amann, Thorben; Beringer, Tim; De Oliveira Garcia, Wagner; Hartmann, Jens; Khanna, Tarun; Lenzi, Dominic; Luderer, Gunnar; Nemet, Gregory F; Rogelj, Joeri; Smith, Pete; Vicente Vicente, Jose Luis; Wilcox, Jennifer; Del Mar Zamora Dominguez, Maria (2018). "Negative emissions: Part 1 – research landscape and synthesis" (PDF). Environmental Research Letters. 13 (6): 063001. Bibcode:2018ERL....13f3001M. doi:10.1088/1748-9326/aabf9b. Archived from the original on March 16, 2020. Retrieved September 13, 2019.
^ IPCC, 2021: Annex VII: Glossary [Matthews, J.B.R., V. Möller, R. van Diemen, J.S. Fuglestvedt, V. MassonDelmotte, C. Méndez, S. Semenov, A. Reisinger (eds.)]. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press. In Press. https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Annex_VII.pdf Archived September 5, 2021, at the Wayback Machine
^ Geden, Oliver (May 2016). "An actionable climate target". Nature Geoscience. 9 (5): 340–342. Bibcode:2016NatGe...9..340G. doi:10.1038/ngeo2699. ISSN 1752-0908. Archived from the original on May 25, 2021. Retrieved March 7, 2021.
^ Schenuit, Felix; Colvin, Rebecca; Fridahl, Mathias; McMullin, Barry; Reisinger, Andy; Sanchez, Daniel L.; Smith, Stephen M.; Torvanger, Asbjørn; Wreford, Anita; Geden, Oliver (March 4, 2021). "Carbon Dioxide Removal Policy in the Making: Assessing Developments in 9 OECD Cases". Frontiers in Climate. 3: 638805. doi:10.3389/fclim.2021.638805. ISSN 2624-9553.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k National Academies of Sciences, Engineering (October 24, 2018). Negative Emissions Technologies and Reliable Sequestration: A Research Agenda. ISBN 978-0-309-48452-7. Archived from the original on November 20, 2021. Retrieved February 22, 2020. {{cite book}}: |archive-date= / |archive-url= timestamp mismatch; November 22, 2021 suggested (help)
^ Vergragt, P.J.; Markusson, N.; Karlsson, H. (2011). "Carbon capture and storage, bio-energy with carbon capture and storage, and the escape from the fossil-fuel lock-in". Global Environmental Change. 21 (2): 282–92. doi:10.1016/j.gloenvcha.2011.01.020.
^ Azar, C.; Lindgren, K.; Larson, E.; Möllersten, K. (2006). "Carbon Capture and Storage from Fossil Fuels and Biomass – Costs and Potential Role in Stabilizing the Atmosphere". Climatic Change. 74 (1–3): 47–79. Bibcode:2006ClCh...74...47A. doi:10.1007/s10584-005-3484-7. S2CID 4850415.
^ Page 4-81, IPCC Sixth Assessment Report Working Group 1, 9/8/21, https://www.ipcc.ch/2021/08/09/ar6-wg1-20210809-pr/ Archived August 11, 2021, at the Wayback Machine
^ IPCC15, Ch 2.
^ Obersteiner, M.; Azar, Ch; Kauppi, P.; Möllersten, K.; Moreira, J.; Nilsson, S.; Read, P.; Riahi, K.; Schlamadinger, B.; Yamagata, Y.; Yan, J. (October 26, 2001). "Managing Climate Risk". Science. 294 (5543): 786–787. doi:10.1126/science.294.5543.786b. PMID 11681318. S2CID 34722068.
^ Pidcock, Roz (September 15, 2015). "The Carbon Brief Interview: Dr Hoesung Lee". Carbon Brief. Retrieved May 19, 2022.
^ Harvey, Fiona (June 5, 2011). "Global warming crisis may mean world has to suck greenhouse gases from air". Guardian Online. Archived from the original on November 6, 2018. Retrieved September 10, 2011.
^ Hollo, Tim (January 15, 2009). "Negative emissions needed for a safe climate". Archived from the original on December 15, 2019. Retrieved September 10, 2011.
^ "National Geographic Magazine - NGM.com". Ngm.nationalgeographic.com. April 25, 2013. Archived from the original on March 22, 2018. Retrieved September 22, 2013.
^ "Snatching Carbon Dioxide from the Atmosphere" (PDF). Cdmc.epp.cmu.edu. Archived from the original (PDF) on March 28, 2013. Retrieved September 22, 2013.
^ ^a ^b ^c "SR15 Technical Summary" (PDF). Archived (PDF) from the original on December 20, 2019. Retrieved July 25, 2019.
^ Anderson, K.; Peters, G. (October 14, 2016). "The trouble with negative emissions". Science. 354 (6309): 182–183. Bibcode:2016Sci...354..182A. doi:10.1126/science.aah4567. hdl:11250/2491451. ISSN 0036-8075. PMID 27738161. S2CID 44896189. Archived from the original on November 22, 2021. Retrieved April 28, 2020.
^ IPCC15 & Ch. 2 p. 124.
^ "Forests and climate change". IUCN. November 11, 2017. Archived from the original on October 9, 2020. Retrieved October 7, 2020.
^ "Forest Protection & Climate Change: Why Is It Important?". Climate Transform. May 13, 2021. Archived from the original on June 3, 2021. Retrieved May 31, 2021.
^ ^a ^b ^c "Greenhouse Gas Removals: Summary of Responses to the Call for Evidence" (PDF). Archived (PDF) from the original on October 20, 2021.
^ IPCC (2021). Masson-Delmotte, V.; Zhai, P.; Pirani, A.; Connors, S. L.; et al. (eds.). Climate Change 2021: The Physical Science Basis (PDF). Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press (In Press). Archived (PDF) from the original on June 5, 2022. Retrieved June 3, 2022.
^ "What is carbon sequestration? | U.S. Geological Survey". www.usgs.gov. Archived from the original on February 6, 2023. Retrieved February 6, 2023.
^ Beerling, David (2008). The Emerald Planet: How Plants Changed Earth's History. Oxford University Press. pp. 194–5. ISBN 978-0-19-954814-9.
^ National Academies Of Sciences, Engineering (2019). Negative Emissions Technologies and Reliable Sequestration: A Research Agenda. Washington, D.C.: National Academies of Sciences, Engineering, and Medicine. pp. 45–136. doi:10.17226/25259. ISBN 978-0-309-48452-7. PMID 31120708. S2CID 134196575.
^ Nath, Arun Jyoti; Lal, Rattan; Das, Ashesh Kumar (January 1, 2015). "Managing woody bamboos for carbon farming and carbon trading". Global Ecology and Conservation. 3: 654–663. doi:10.1016/j.gecco.2015.03.002. ISSN 2351-9894.
^ "Carbon Farming | Carbon Cycle Institute". www.carboncycle.org. Archived from the original on May 21, 2021. Retrieved April 27, 2018.
^ Almaraz, Maya; Wong, Michelle Y.; Geoghegan, Emily K.; Houlton, Benjamin Z. (2021). "A review of carbon farming impacts on nitrogen cycling, retention, and loss". Annals of the New York Academy of Sciences. 1505 (1): 102–117. doi:10.1111/nyas.14690. ISSN 0077-8923. S2CID 238202676.
^ Jindal, Rohit; Swallow, Brent; Kerr, John (2008). "Forestry-based carbon sequestration projects in Africa: Potential benefits and challenges". Natural Resources Forum. 32 (2): 116–130. doi:10.1111/j.1477-8947.2008.00176.x. ISSN 1477-8947.
^ Tang, Kai; Kragt, Marit E.; Hailu, Atakelty; Ma, Chunbo (May 1, 2016). "Carbon farming economics: What have we learned?". Journal of Environmental Management. 172: 49–57. doi:10.1016/j.jenvman.2016.02.008. ISSN 0301-4797. PMID 26921565.
^ Burton, David. "How carbon farming can help solve climate change". The Conversation. Retrieved April 27, 2018.
^ ^a ^b Lin, Brenda B.; Macfadyen, Sarina; Renwick, Anna R.; Cunningham, Saul A.; Schellhorn, Nancy A. (October 1, 2013). "Maximizing the Environmental Benefits of Carbon Farming through Ecosystem Service Delivery". BioScience. 63 (10): 793–803. doi:10.1525/bio.2013.63.10.6. ISSN 0006-3568.
^ Huxham, M.; Whitlock, D.; Githaiga, M.; Dencer-Brown, A. (2018). "Carbon in the Coastal Seascape: How Interactions Between Mangrove Forests, Seagrass Meadows and Tidal Marshes Influence Carbon Storage". Current Forestry Reports. 4 (2): 101–110. doi:10.1007/s40725-018-0077-4. S2CID 135243725. Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. Archived 2017-10-16 at the Wayback Machine.
^ ^a ^b ^c IPCC, 2021: Annex VII: Glossary [Matthews, J. B. R., V. Möller, R. van Diemen, J. S. Fuglestvedt, V. Masson-Delmotte, C. Méndez, S. Semenov, A. Reisinger (eds.)]. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 2215–2256, doi:10.1017/9781009157896.022.
^ Canadell, J. G., P. M. S. Monteiro, M. H. Costa, L. Cotrim da Cunha, P. M. Cox, A. V. Eliseev, S. Henson, M. Ishii, S. Jaccard, C. Koven, A. Lohila, P. K. Patra, S. Piao, J. Rogelj, S. Syampungani, S. Zaehle, and K. Zickfeld, 2021: Chapter 5: Global Carbon and other Biogeochemical Cycles and Feedbacks. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 673–816, doi:10.1017/9781009157896.007.
^ ^a ^b Ricart, Aurora M.; Krause-Jensen, Dorte; Hancke, Kasper; Price, Nichole N.; Masqué, Pere; Duarte, Carlos M. (2022). "Sinking seaweed in the deep ocean for carbon neutrality is ahead of science and beyond the ethics". Environmental Research Letters. 17 (8): 081003. Bibcode:2022ERL....17h1003R. doi:10.1088/1748-9326/ac82ff. hdl:10754/679874. S2CID 250973225.
^ Hurd, Catriona L.; Law, Cliff S.; Bach, Lennart T.; Britton, Damon; Hovenden, Mark; Paine, Ellie R.; Raven, John A.; Tamsitt, Veronica; Boyd, Philip W. (2022). "Forensic carbon accounting: Assessing the role of seaweeds for carbon sequestration". Journal of Phycology. 58 (3): 347–363. doi:10.1111/jpy.13249. PMID 35286717. S2CID 247453370.
^ Boyd, Philip W.; Bach, Lennart T.; Hurd, Catriona L.; Paine, Ellie; Raven, John A.; Tamsitt, Veronica (2022). "Potential negative effects of ocean afforestation on offshore ecosystems". Nature Ecology & Evolution. 6 (6): 675–683. doi:10.1038/s41559-022-01722-1. PMID 35449458. S2CID 248322820.
^ "What Is Blue Carbon?". CarbonBetter. November 4, 2022. Retrieved May 20, 2023.
^ Obersteiner, M. (2001). "Managing Climate Risk". Science. 294 (5543): 786–7. doi:10.1126/science.294.5543.786b. PMID 11681318. S2CID 34722068.
^ ^a ^b National Academies of Sciences, Engineering (October 24, 2018). Negative Emissions Technologies and Reliable Sequestration: A Research Agenda. doi:10.17226/25259. ISBN 978-0-309-48452-7. PMID 31120708. S2CID 134196575. Archived from the original on May 25, 2020. Retrieved February 22, 2020.
^ Deprez, Alexandra; Leadley, Paul; Dooley, Kate; Williamson, Phil; Cramer, Wolfgang; Gattuso, Jean-Pierre; Rankovic, Aleksandar; Carlson, Eliot L.; Creutzig, Felix (February 2, 2024). "Sustainability limits needed for CO 2 removal". Science. 383 (6682): 484–486. doi:10.1126/science.adj6171. ISSN 0036-8075. PMID 38301011. S2CID 267365599.
^ Smith, Pete; Porter, John R. (July 2018). "Bioenergy in the IPCC Assessments". GCB Bioenergy. 10 (7): 428–431. Bibcode:2018GCBBi..10..428S. doi:10.1111/gcbb.12514. hdl:2164/10480.
^ "BECCS 2019 perspective" (PDF). Archived (PDF) from the original on March 31, 2020. Retrieved June 11, 2019.
^ Rhodes, James S.; Keith, David W. (2008). "Biomass with capture: Negative emissions within social and environmental constraints: An editorial comment". Climatic Change. 87 (3–4): 321–8. Bibcode:2008ClCh...87..321R. doi:10.1007/s10584-007-9387-4.
^ Fajardy, Mathilde; Köberle, Alexandre; Mac Dowell, Niall; Fantuzzi, Andrea (2019). "BECCS deployment: a reality check" (PDF). Grantham Institute Imperial College London.
^ "What is biochar?". UK Biochar research center. University of Edinburgh Kings Buildings Edinburgh. Archived from the original on October 1, 2019. Retrieved April 25, 2016.
^ "What is Biomass?". Biomass Energy Center. Direct.gov.uk. Archived from the original on October 3, 2016. Retrieved April 25, 2016.
^ "Biochar reducing and removing CO2 while improving soils: A significant sustainable response to climate change" (PDF). UKBRC. UK Biochar research Center. Archived (PDF) from the original on November 5, 2016. Retrieved April 25, 2016.
^ "Maps show rocks ideal for sequestering carbon". The New York Times. Archived from the original on May 16, 2018. Retrieved May 15, 2018.
^ U.S. Department of the Interior. "Mapping the Mineral Resource Base for Mineral Carbon-Dioxide Sequestration in the Conterminous United States" (PDF). U.S. Geological Survey. Data Series 414. Archived (PDF) from the original on July 27, 2020. Retrieved May 15, 2018.
^ "Cloud spraying and hurricane slaying: how ocean geoengineering became the frontier of the climate crisis". The Guardian. June 23, 2021. Archived from the original on June 23, 2021. Retrieved June 23, 2021.
^ "CarbFix Project | Global Carbon Capture and Storage Institute". www.globalccsinstitute.com. Archived from the original on July 3, 2018. Retrieved May 15, 2018.
^ "The CarbFix Project". www.or.is (in Icelandic). August 22, 2017. Archived from the original on May 16, 2018. Retrieved May 15, 2018.
^ "Turning Carbon Dioxide Into Rock, and Burying It". The New York Times. February 9, 2015. ISSN 0362-4331. Archived from the original on May 16, 2018. Retrieved May 15, 2018.
^ "Direct Air Capture / A key technology for net zero" (PDF). International Energy Agency (IEA). April 2022. p. 18. Archived (PDF) from the original on April 10, 2022.
^ European Commission. Directorate General for Research and Innovation; European Commission's Group of Chief Scientific Advisors (2018). Novel carbon capture and utilisation technologies. Publications Office. doi:10.2777/01532.^{[page needed]}
^ ^a ^b Erans, María; Sanz-Pérez, Eloy S.; Hanak, Dawid P.; Clulow, Zeynep; Reiner, David M.; Mutch, Greg A. (2022). "Direct air capture: process technology, techno-economic and socio-political challenges". Energy & Environmental Science. 15 (4): 1360–1405. doi:10.1039/D1EE03523A. hdl:10115/19074. S2CID 247178548.
^ Keith, David W.; Holmes, Geoffrey; St. Angelo, David; Heide, Kenton (June 7, 2018). "A Process for Capturing CO₂ from the Atmosphere". Joule. 2 (8): 1573–1594. doi:10.1016/j.joule.2018.05.006.
^ Beuttler, Christoph; Charles, Louise; Wurzbacher, Jan (November 21, 2019). "The Role of Direct Air Capture in Mitigation of Anthropogenic Greenhouse Gas Emissions". Frontiers in Climate. 1: 10. doi:10.3389/fclim.2019.00010.
^ Quarton, Christopher J.; Samsatli, Sheila (January 1, 2020). "The value of hydrogen and carbon capture, storage and utilisation in decarbonising energy: Insights from integrated value chain optimisation" (PDF). Applied Energy. 257: 113936. Bibcode:2020ApEn..25713936Q. doi:10.1016/j.apenergy.2019.113936. S2CID 208829001.
^ "Carbon-dioxide-removal options are multiplying". The Economist. November 20, 2023.
^ "The many prices of carbon dioxide". The Economist. November 20, 2023.
^ Sanz-Pérez, Eloy S.; Murdock, Christopher R.; Didas, Stephanie A.; Jones, Christopher W. (October 12, 2016). "Direct Capture of carbon dioxide from Ambient Air". Chemical Reviews. 116 (19): 11840–11876. doi:10.1021/acs.chemrev.6b00173. PMID 27560307.
^ "Direct Air Capture (Technology Factsheet)" (PDF). Geoengineering Monitor. May 24, 2018. Archived (PDF) from the original on August 26, 2019. Retrieved August 27, 2019.
^ "How Finland's Puro.earth plans to scale up carbon removal to help the world reach net zero emissions". European CEO. July 1, 2021. Archived from the original on July 1, 2021.
^ Lebling, Katie; McQueen, Noah; Pisciotta, Max; Wilcox, Jennifer (January 6, 2021). "Direct Air Capture: Resource Considerations and Costs for Carbon Removal". Archived from the original on May 13, 2021. Retrieved May 13, 2021. {{cite journal}}: Cite journal requires |journal= (help)
^ Brown, James (February 21, 2021). "New Biochar technology a game changer for carbon capture market". The Land. Archived from the original on February 21, 2021. Retrieved December 10, 2021.
^ Myles, Allen (February 2020). "The Oxford Principles for Net Zero Aligned Carbon Offsetting" (PDF). Archived (PDF) from the original on October 2, 2020. Retrieved December 10, 2020.
^ Myles, Allen (September 2020). "The Oxford Principles for Net Zero Aligned Carbon Offsetting" (PDF). Archived (PDF) from the original on October 2, 2020. Retrieved December 10, 2021.
^ Giles, Jim (February 10, 2020). "Carbon markets get real on removal". Archived from the original on February 15, 2020. Retrieved December 10, 2021.
^ @elonmusk (January 21, 2021). "Am donating $100M towards a prize for best carbon capture technology" (Tweet) – via Twitter.
^ Tamme, Eve; Beck, Larissa Lee (2021). "European Carbon Dioxide Removal Policy: Current Status and Future Opportunities". Frontiers in Climate. 3: 120. doi:10.3389/fclim.2021.682882. ISSN 2624-9553.
^ Elkerbout, Milan; Bryhn, Julie. "Setting the context for an EU policy framework for negative emissions" (PDF). Centre for European Policy Studies. Archived (PDF) from the original on December 10, 2021.
^ Evans, Michael (December 8, 2021). "Spotlight: EU carbon price strengthens to record highs in November". www.spglobal.com. Retrieved December 10, 2021.
^ "Pricing Carbon". The World Bank. Archived from the original on June 2, 2014. Retrieved December 20, 2021.
^ Robinson Meyer (April 23, 2022). "We've Never Seen a Carbon-Removal Plan Like This Before". The Atlantic. Retrieved April 29, 2022.
^ Lackner, Klaus S. (2020). "Practical constraints on atmospheric methane removal". Nature Sustainability. 3 (5): 357. doi:10.1038/s41893-020-0496-7. ISSN 2398-9629.

External links

Deep Dives by Carbon180. Info about carbon removal solutions.

Krupp, Fred; Keohane, Nathaniel; Pooley, Eric (September 25, 2019). "Less Than Zero; Can Carbon-Removal Technologies Curb Climate Change?". Foreign Affairs (March/April 2019): 142–152.
The Road to Ten Gigatons - Carbon Removal Scale Up Challenge Game.

[:0-1] Intergovernmental Panel on Climate Change. "Glossary — Global Warming of 1.5 ºC". Archived from the original on December 22, 2019. Retrieved February 23, 2020.

[RoyalSociety-2] "Geoengineering the climate: science, governance and uncertainty". The Royal Society. 2009. Archived from the original on October 23, 2019. Retrieved September 10, 2011.

[Negative_emissions:_Part_1_–_research_landscape_and_synthesis-3] Minx, Jan C; Lamb, William F; Callaghan, Max W; Fuss, Sabine; Hilaire, Jérôme; Creutzig, Felix; Amann, Thorben; Beringer, Tim; De Oliveira Garcia, Wagner; Hartmann, Jens; Khanna, Tarun; Lenzi, Dominic; Luderer, Gunnar; Nemet, Gregory F; Rogelj, Joeri; Smith, Pete; Vicente Vicente, Jose Luis; Wilcox, Jennifer; Del Mar Zamora Dominguez, Maria (2018). "Negative emissions: Part 1 – research landscape and synthesis" (PDF). Environmental Research Letters. 13 (6): 063001. Bibcode:2018ERL....13f3001M. doi:10.1088/1748-9326/aabf9b. Archived from the original on March 16, 2020. Retrieved September 13, 2019.

[4] IPCC, 2021: Annex VII: Glossary [Matthews, J.B.R., V. Möller, R. van Diemen, J.S. Fuglestvedt, V. MassonDelmotte, C. Méndez, S. Semenov, A. Reisinger (eds.)]. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press. In Press. https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Annex_VII.pdf Archived September 5, 2021, at the Wayback Machine

[5] Geden, Oliver (May 2016). "An actionable climate target". Nature Geoscience. 9 (5): 340–342. Bibcode:2016NatGe...9..340G. doi:10.1038/ngeo2699. ISSN 1752-0908. Archived from the original on May 25, 2021. Retrieved March 7, 2021.

[6] Schenuit, Felix; Colvin, Rebecca; Fridahl, Mathias; McMullin, Barry; Reisinger, Andy; Sanchez, Daniel L.; Smith, Stephen M.; Torvanger, Asbjørn; Wreford, Anita; Geden, Oliver (March 4, 2021). "Carbon Dioxide Removal Policy in the Making: Assessing Developments in 9 OECD Cases". Frontiers in Climate. 3: 638805. doi:10.3389/fclim.2021.638805. ISSN 2624-9553.

[:2-7] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j ^k National Academies of Sciences, Engineering (October 24, 2018). Negative Emissions Technologies and Reliable Sequestration: A Research Agenda. ISBN 978-0-309-48452-7. Archived from the original on November 20, 2021. Retrieved February 22, 2020. {{cite book}}: |archive-date= / |archive-url= timestamp mismatch; November 22, 2021 suggested (help)

[Vergragt-8] Vergragt, P.J.; Markusson, N.; Karlsson, H. (2011). "Carbon capture and storage, bio-energy with carbon capture and storage, and the escape from the fossil-fuel lock-in". Global Environmental Change. 21 (2): 282–92. doi:10.1016/j.gloenvcha.2011.01.020.

[Azar-9] Azar, C.; Lindgren, K.; Larson, E.; Möllersten, K. (2006). "Carbon Capture and Storage from Fossil Fuels and Biomass – Costs and Potential Role in Stabilizing the Atmosphere". Climatic Change. 74 (1–3): 47–79. Bibcode:2006ClCh...74...47A. doi:10.1007/s10584-005-3484-7. S2CID 4850415.

[10] Page 4-81, IPCC Sixth Assessment Report Working Group 1, 9/8/21, https://www.ipcc.ch/2021/08/09/ar6-wg1-20210809-pr/ Archived August 11, 2021, at the Wayback Machine

[FOOTNOTEIPCC15Ch_2-11] IPCC15, Ch 2.

[12] Obersteiner, M.; Azar, Ch; Kauppi, P.; Möllersten, K.; Moreira, J.; Nilsson, S.; Read, P.; Riahi, K.; Schlamadinger, B.; Yamagata, Y.; Yan, J. (October 26, 2001). "Managing Climate Risk". Science. 294 (5543): 786–787. doi:10.1126/science.294.5543.786b. PMID 11681318. S2CID 34722068.

[13] Pidcock, Roz (September 15, 2015). "The Carbon Brief Interview: Dr Hoesung Lee". Carbon Brief. Retrieved May 19, 2022.

[14] Harvey, Fiona (June 5, 2011). "Global warming crisis may mean world has to suck greenhouse gases from air". Guardian Online. Archived from the original on November 6, 2018. Retrieved September 10, 2011.

[15] Hollo, Tim (January 15, 2009). "Negative emissions needed for a safe climate". Archived from the original on December 15, 2019. Retrieved September 10, 2011.

[16] "National Geographic Magazine - NGM.com". Ngm.nationalgeographic.com. April 25, 2013. Archived from the original on March 22, 2018. Retrieved September 22, 2013.

[CDMC-17] "Snatching Carbon Dioxide from the Atmosphere" (PDF). Cdmc.epp.cmu.edu. Archived from the original (PDF) on March 28, 2013. Retrieved September 22, 2013.

[:1-18] "SR15 Technical Summary" (PDF). Archived (PDF) from the original on December 20, 2019. Retrieved July 25, 2019.

[19] Anderson, K.; Peters, G. (October 14, 2016). "The trouble with negative emissions". Science. 354 (6309): 182–183. Bibcode:2016Sci...354..182A. doi:10.1126/science.aah4567. hdl:11250/2491451. ISSN 0036-8075. PMID 27738161. S2CID 44896189. Archived from the original on November 22, 2021. Retrieved April 28, 2020.

[FOOTNOTEIPCC15Ch._2_p._124-20] IPCC15 & Ch. 2 p. 124.

[21] "Forests and climate change". IUCN. November 11, 2017. Archived from the original on October 9, 2020. Retrieved October 7, 2020.

[22] "Forest Protection & Climate Change: Why Is It Important?". Climate Transform. May 13, 2021. Archived from the original on June 3, 2021. Retrieved May 31, 2021.

[:3-23] "Greenhouse Gas Removals: Summary of Responses to the Call for Evidence" (PDF). Archived (PDF) from the original on October 20, 2021.

[Carbon_sequestration_Masson-Delmotte-24] IPCC (2021). Masson-Delmotte, V.; Zhai, P.; Pirani, A.; Connors, S. L.; et al. (eds.). Climate Change 2021: The Physical Science Basis (PDF). Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press (In Press). Archived (PDF) from the original on June 5, 2022. Retrieved June 3, 2022.

[Carbon_sequestration_:8-25] "What is carbon sequestration? | U.S. Geological Survey". www.usgs.gov. Archived from the original on February 6, 2023. Retrieved February 6, 2023.

[Beerling-26] Beerling, David (2008). The Emerald Planet: How Plants Changed Earth's History. Oxford University Press. pp. 194–5. ISBN 978-0-19-954814-9.

[27] National Academies Of Sciences, Engineering (2019). Negative Emissions Technologies and Reliable Sequestration: A Research Agenda. Washington, D.C.: National Academies of Sciences, Engineering, and Medicine. pp. 45–136. doi:10.17226/25259. ISBN 978-0-309-48452-7. PMID 31120708. S2CID 134196575.

[28] Nath, Arun Jyoti; Lal, Rattan; Das, Ashesh Kumar (January 1, 2015). "Managing woody bamboos for carbon farming and carbon trading". Global Ecology and Conservation. 3: 654–663. doi:10.1016/j.gecco.2015.03.002. ISSN 2351-9894.

[Carbon_farming_CCI-2021-29] "Carbon Farming | Carbon Cycle Institute". www.carboncycle.org. Archived from the original on May 21, 2021. Retrieved April 27, 2018.

[30] Almaraz, Maya; Wong, Michelle Y.; Geoghegan, Emily K.; Houlton, Benjamin Z. (2021). "A review of carbon farming impacts on nitrogen cycling, retention, and loss". Annals of the New York Academy of Sciences. 1505 (1): 102–117. doi:10.1111/nyas.14690. ISSN 0077-8923. S2CID 238202676.

[Carbon_farming_Jindal-2008-31] Jindal, Rohit; Swallow, Brent; Kerr, John (2008). "Forestry-based carbon sequestration projects in Africa: Potential benefits and challenges". Natural Resources Forum. 32 (2): 116–130. doi:10.1111/j.1477-8947.2008.00176.x. ISSN 1477-8947.

[Carbon_farming_Tang-2016-32] Tang, Kai; Kragt, Marit E.; Hailu, Atakelty; Ma, Chunbo (May 1, 2016). "Carbon farming economics: What have we learned?". Journal of Environmental Management. 172: 49–57. doi:10.1016/j.jenvman.2016.02.008. ISSN 0301-4797. PMID 26921565.

[Carbon_farming_Burton-2018-33] Burton, David. "How carbon farming can help solve climate change". The Conversation. Retrieved April 27, 2018.

[Carbon_farming_Lin-2013-34] Lin, Brenda B.; Macfadyen, Sarina; Renwick, Anna R.; Cunningham, Saul A.; Schellhorn, Nancy A. (October 1, 2013). "Maximizing the Environmental Benefits of Carbon Farming through Ecosystem Service Delivery". BioScience. 63 (10): 793–803. doi:10.1525/bio.2013.63.10.6. ISSN 0006-3568.

[Blue_carbon_Huxham2018-35] Huxham, M.; Whitlock, D.; Githaiga, M.; Dencer-Brown, A. (2018). "Carbon in the Coastal Seascape: How Interactions Between Mangrove Forests, Seagrass Meadows and Tidal Marshes Influence Carbon Storage". Current Forestry Reports. 4 (2): 101–110. doi:10.1007/s40725-018-0077-4. S2CID 135243725. Material was copied from this source, which is available under a Creative Commons Attribution 4.0 International License. Archived 2017-10-16 at the Wayback Machine.

[Blue_carbon_IPCC_AR6_WGI_Glossary-36] IPCC, 2021: Annex VII: Glossary [Matthews, J. B. R., V. Möller, R. van Diemen, J. S. Fuglestvedt, V. Masson-Delmotte, C. Méndez, S. Semenov, A. Reisinger (eds.)]. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 2215–2256, doi:10.1017/9781009157896.022.

[Blue_carbon_:2-37] Canadell, J. G., P. M. S. Monteiro, M. H. Costa, L. Cotrim da Cunha, P. M. Cox, A. V. Eliseev, S. Henson, M. Ishii, S. Jaccard, C. Koven, A. Lohila, P. K. Patra, S. Piao, J. Rogelj, S. Syampungani, S. Zaehle, and K. Zickfeld, 2021: Chapter 5: Global Carbon and other Biogeochemical Cycles and Feedbacks. In Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S. L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M. I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J. B. R. Matthews, T. K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, pp. 673–816, doi:10.1017/9781009157896.007.

[Blue_carbon_Ricart2022-38] Ricart, Aurora M.; Krause-Jensen, Dorte; Hancke, Kasper; Price, Nichole N.; Masqué, Pere; Duarte, Carlos M. (2022). "Sinking seaweed in the deep ocean for carbon neutrality is ahead of science and beyond the ethics". Environmental Research Letters. 17 (8): 081003. Bibcode:2022ERL....17h1003R. doi:10.1088/1748-9326/ac82ff. hdl:10754/679874. S2CID 250973225.

[39] Hurd, Catriona L.; Law, Cliff S.; Bach, Lennart T.; Britton, Damon; Hovenden, Mark; Paine, Ellie R.; Raven, John A.; Tamsitt, Veronica; Boyd, Philip W. (2022). "Forensic carbon accounting: Assessing the role of seaweeds for carbon sequestration". Journal of Phycology. 58 (3): 347–363. doi:10.1111/jpy.13249. PMID 35286717. S2CID 247453370.

[Blue_carbon_Boyd2022-40] Boyd, Philip W.; Bach, Lennart T.; Hurd, Catriona L.; Paine, Ellie; Raven, John A.; Tamsitt, Veronica (2022). "Potential negative effects of ocean afforestation on offshore ecosystems". Nature Ecology & Evolution. 6 (6): 675–683. doi:10.1038/s41559-022-01722-1. PMID 35449458. S2CID 248322820.

[41] "What Is Blue Carbon?". CarbonBetter. November 4, 2022. Retrieved May 20, 2023.

[Bioenergy_with_carbon_capture_and_storage_Obersteiner2-42] Obersteiner, M. (2001). "Managing Climate Risk". Science. 294 (5543): 786–7. doi:10.1126/science.294.5543.786b. PMID 11681318. S2CID 34722068.

[Bioenergy_with_carbon_capture_and_storage_:3-43] National Academies of Sciences, Engineering (October 24, 2018). Negative Emissions Technologies and Reliable Sequestration: A Research Agenda. doi:10.17226/25259. ISBN 978-0-309-48452-7. PMID 31120708. S2CID 134196575. Archived from the original on May 25, 2020. Retrieved February 22, 2020.

[44] Deprez, Alexandra; Leadley, Paul; Dooley, Kate; Williamson, Phil; Cramer, Wolfgang; Gattuso, Jean-Pierre; Rankovic, Aleksandar; Carlson, Eliot L.; Creutzig, Felix (February 2, 2024). "Sustainability limits needed for CO 2 removal". Science. 383 (6682): 484–486. doi:10.1126/science.adj6171. ISSN 0036-8075. PMID 38301011. S2CID 267365599.

[45] Smith, Pete; Porter, John R. (July 2018). "Bioenergy in the IPCC Assessments". GCB Bioenergy. 10 (7): 428–431. Bibcode:2018GCBBi..10..428S. doi:10.1111/gcbb.12514. hdl:2164/10480.

[46] "BECCS 2019 perspective" (PDF). Archived (PDF) from the original on March 31, 2020. Retrieved June 11, 2019.

[Bioenergy_with_carbon_capture_and_storage_rhodes2-47] Rhodes, James S.; Keith, David W. (2008). "Biomass with capture: Negative emissions within social and environmental constraints: An editorial comment". Climatic Change. 87 (3–4): 321–8. Bibcode:2008ClCh...87..321R. doi:10.1007/s10584-007-9387-4.

[48] Fajardy, Mathilde; Köberle, Alexandre; Mac Dowell, Niall; Fantuzzi, Andrea (2019). "BECCS deployment: a reality check" (PDF). Grantham Institute Imperial College London.

[49] "What is biochar?". UK Biochar research center. University of Edinburgh Kings Buildings Edinburgh. Archived from the original on October 1, 2019. Retrieved April 25, 2016.

[50] "What is Biomass?". Biomass Energy Center. Direct.gov.uk. Archived from the original on October 3, 2016. Retrieved April 25, 2016.

[51] "Biochar reducing and removing CO2 while improving soils: A significant sustainable response to climate change" (PDF). UKBRC. UK Biochar research Center. Archived (PDF) from the original on November 5, 2016. Retrieved April 25, 2016.

[52] "Maps show rocks ideal for sequestering carbon". The New York Times. Archived from the original on May 16, 2018. Retrieved May 15, 2018.

[53] U.S. Department of the Interior. "Mapping the Mineral Resource Base for Mineral Carbon-Dioxide Sequestration in the Conterminous United States" (PDF). U.S. Geological Survey. Data Series 414. Archived (PDF) from the original on July 27, 2020. Retrieved May 15, 2018.

[54] "Cloud spraying and hurricane slaying: how ocean geoengineering became the frontier of the climate crisis". The Guardian. June 23, 2021. Archived from the original on June 23, 2021. Retrieved June 23, 2021.

[55] "CarbFix Project | Global Carbon Capture and Storage Institute". www.globalccsinstitute.com. Archived from the original on July 3, 2018. Retrieved May 15, 2018.

[56] "The CarbFix Project". www.or.is (in Icelandic). August 22, 2017. Archived from the original on May 16, 2018. Retrieved May 15, 2018.

[57] "Turning Carbon Dioxide Into Rock, and Burying It". The New York Times. February 9, 2015. ISSN 0362-4331. Archived from the original on May 16, 2018. Retrieved May 15, 2018.

[IEA_202204-58] "Direct Air Capture / A key technology for net zero" (PDF). International Energy Agency (IEA). April 2022. p. 18. Archived (PDF) from the original on April 10, 2022.

[Direct_air_capture_:4-59] European Commission. Directorate General for Research and Innovation; European Commission's Group of Chief Scientific Advisors (2018). Novel carbon capture and utilisation technologies. Publications Office. doi:10.2777/01532.^{[page needed]}

[Direct_air_capture_Erans_Sanz-Pérez_Hanak_et_al_2022-60] Erans, María; Sanz-Pérez, Eloy S.; Hanak, Dawid P.; Clulow, Zeynep; Reiner, David M.; Mutch, Greg A. (2022). "Direct air capture: process technology, techno-economic and socio-political challenges". Energy & Environmental Science. 15 (4): 1360–1405. doi:10.1039/D1EE03523A. hdl:10115/19074. S2CID 247178548.

[Direct_air_capture_:10-61] Keith, David W.; Holmes, Geoffrey; St. Angelo, David; Heide, Kenton (June 7, 2018). "A Process for Capturing CO₂ from the Atmosphere". Joule. 2 (8): 1573–1594. doi:10.1016/j.joule.2018.05.006.

[62] Beuttler, Christoph; Charles, Louise; Wurzbacher, Jan (November 21, 2019). "The Role of Direct Air Capture in Mitigation of Anthropogenic Greenhouse Gas Emissions". Frontiers in Climate. 1: 10. doi:10.3389/fclim.2019.00010.

[63] Quarton, Christopher J.; Samsatli, Sheila (January 1, 2020). "The value of hydrogen and carbon capture, storage and utilisation in decarbonising energy: Insights from integrated value chain optimisation" (PDF). Applied Energy. 257: 113936. Bibcode:2020ApEn..25713936Q. doi:10.1016/j.apenergy.2019.113936. S2CID 208829001.

[Direct_air_capture_:3-64] "Carbon-dioxide-removal options are multiplying". The Economist. November 20, 2023.

[65] "The many prices of carbon dioxide". The Economist. November 20, 2023.

[Direct_air_capture_ReviewDAC2016-66] Sanz-Pérez, Eloy S.; Murdock, Christopher R.; Didas, Stephanie A.; Jones, Christopher W. (October 12, 2016). "Direct Capture of carbon dioxide from Ambient Air". Chemical Reviews. 116 (19): 11840–11876. doi:10.1021/acs.chemrev.6b00173. PMID 27560307.

[Direct_air_capture_:02-67] "Direct Air Capture (Technology Factsheet)" (PDF). Geoengineering Monitor. May 24, 2018. Archived (PDF) from the original on August 26, 2019. Retrieved August 27, 2019.

[68] "How Finland's Puro.earth plans to scale up carbon removal to help the world reach net zero emissions". European CEO. July 1, 2021. Archived from the original on July 1, 2021.

[69] Lebling, Katie; McQueen, Noah; Pisciotta, Max; Wilcox, Jennifer (January 6, 2021). "Direct Air Capture: Resource Considerations and Costs for Carbon Removal". Archived from the original on May 13, 2021. Retrieved May 13, 2021. {{cite journal}}: Cite journal requires |journal= (help)

[70] Brown, James (February 21, 2021). "New Biochar technology a game changer for carbon capture market". The Land. Archived from the original on February 21, 2021. Retrieved December 10, 2021.

[71] Myles, Allen (February 2020). "The Oxford Principles for Net Zero Aligned Carbon Offsetting" (PDF). Archived (PDF) from the original on October 2, 2020. Retrieved December 10, 2020.

[72] Myles, Allen (September 2020). "The Oxford Principles for Net Zero Aligned Carbon Offsetting" (PDF). Archived (PDF) from the original on October 2, 2020. Retrieved December 10, 2021.

[73] Giles, Jim (February 10, 2020). "Carbon markets get real on removal". Archived from the original on February 15, 2020. Retrieved December 10, 2021.

[74] @elonmusk (January 21, 2021). "Am donating $100M towards a prize for best carbon capture technology" (Tweet) – via Twitter.

[75] Tamme, Eve; Beck, Larissa Lee (2021). "European Carbon Dioxide Removal Policy: Current Status and Future Opportunities". Frontiers in Climate. 3: 120. doi:10.3389/fclim.2021.682882. ISSN 2624-9553.

[76] Elkerbout, Milan; Bryhn, Julie. "Setting the context for an EU policy framework for negative emissions" (PDF). Centre for European Policy Studies. Archived (PDF) from the original on December 10, 2021.

[77] Evans, Michael (December 8, 2021). "Spotlight: EU carbon price strengthens to record highs in November". www.spglobal.com. Retrieved December 10, 2021.

[78] "Pricing Carbon". The World Bank. Archived from the original on June 2, 2014. Retrieved December 20, 2021.

[79] Robinson Meyer (April 23, 2022). "We've Never Seen a Carbon-Removal Plan Like This Before". The Atlantic. Retrieved April 29, 2022.

[80] Lackner, Klaus S. (2020). "Practical constraints on atmospheric methane removal". Nature Sustainability. 3 (5): 357. doi:10.1038/s41893-020-0496-7. ISSN 2398-9629.

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[8]

[9]

[10]

[11]

[12]

[13]

[14]

[15]

[16]

[17]

[18]

[19]

[20]

[21]

[22]

[23]

[24]

[25]

[26]

[27]

[28]

[29]

[30]

[31]

[32]

[33]

[34]

[35]

[36]

[37]

[38]

[39]

[40]

[41]

[42]

[43]

[44]

[45]

[46]

[47]

[48]

[49]

[50]

[51]

[52]

[53]

[54]

[55]

[56]

[57]

[58]

[59]

[60]

[61]

[62]

[63]

[64]

[65]

[66]

[67]

[68]

[69]

[70]

[71]

[72]

[73]

[74]

[75]

[76]

[77]

[78]

[79]

[80]

@@ Line 50: / Line 50: @@
 {{excerpt|Carbon sequestration|paragraphs=1-2|file=no}}
-=== Biosequestration ===
+==== Biosequestration ====
 {{Main|Biosequestration}}
 [[Biosequestration]] is the capture and storage of the atmospheric [[greenhouse gas]] [[carbon dioxide]] by continual or enhanced biological processes. This form of [[carbon sequestration]] occurs through increased rates of [[photosynthesis]] via [[Land use|land-use]] practices such as [[reforestation]], [[Sustainability|sustainable]] [[forest management]], and [[genetic engineering]]. The [[Salk Institute for Biological Studies|SALK]] [[Harnessing Plants Initiative]] led by [[Joanne Chory]] is an example of an [[Biosequestration#Enhanced photosynthesis|enhanced photosynthesis]] initiative<ref name="Beerling">{{cite book|author=Beerling, David|title=The Emerald Planet: How Plants Changed Earth's History|publisher=Oxford University Press|year=2008|isbn=978-0-19-954814-9|pages=194–5|author-link=David Beerling}}</ref><ref>{{Cite book|last1=National Academies Of Sciences|first1=Engineering|title=Negative Emissions Technologies and Reliable Sequestration: A Research Agenda|publisher=National Academies of Sciences, Engineering, and Medicine|year=2019|isbn=978-0-309-48452-7|location=Washington, D.C.|pages=45–136|language=en|doi=10.17226/25259|pmid=31120708|s2cid=134196575}}</ref> Carbon sequestration through [[biological processes]] affects the global [[carbon cycle]].
-===Agricultural practices===
+==== Agricultural practices ====
-{{See also|Climate change and agriculture#Impact of agriculture on climate change}}
+{{See also|Greenhouse gas emissions from agriculture}}
 {{excerpt|Carbon farming}}
-===Wetland restoration===
+==== Wetland restoration ====
 {{excerpt|blue carbon}}
-===Bioenergy with carbon capture & storage===
+==== Bioenergy with carbon capture & storage ====
 {{Excerpt|Bioenergy with carbon capture and storage}}
-===Biochar===
+==== Biochar ====
 {{Main|Biochar}}
@@ Line 70: / Line 70: @@
 [[Biochar]] is a charcoal that is used for agricultural purposes which also aids in [[carbon sequestration]], the capture or hold of carbon.  It is created using a process called pyrolysis, which is basically the act of high temperature heating biomass in an environment with low oxygen levels.  What remains is a material known as char, similar to charcoal but is made through a sustainable process, thus the use of biomass.<ref>{{cite web|title=What is biochar?|url=http://www.biochar.ac.uk/what_is_biochar.php|website=UK Biochar research center|publisher=University of Edinburgh Kings Buildings Edinburgh|access-date=25 April 2016|archive-date=October 1, 2019|archive-url=https://web.archive.org/web/20191001070549/https://www.biochar.ac.uk/what_is_biochar.php|url-status=live}}</ref>  Biomass is organic matter produced by living organisms or recently living organisms, most commonly plants or plant based material.<ref>{{cite web|title=What is Biomass?|url=http://www.biomassenergycentre.org.uk/portal/page?_pageid=76,15049&_dad=portal|website=Biomass Energy Center|publisher=Direct.gov.uk|access-date=25 April 2016|archive-url=https://web.archive.org/web/20161003092000/http://www.biomassenergycentre.org.uk/portal/page?_pageid=76,15049&_dad=portal|archive-date=October 3, 2016|url-status=dead}}</ref> A study done by the UK Biochar Research Center has stated that, on a conservative level, biochar can store 1 gigaton of carbon per year.  With greater effort in marketing and acceptance of biochar, the benefit could be the storage of 5–9 gigatons per year of carbon in biochar soils.<ref>{{cite web|url=http://www.ierm.ed.ac.uk/homes/sshackle/WP2.pdf|title=Biochar reducing and removing CO2 while improving soils: A significant sustainable response to climate change|website=UKBRC|publisher=UK Biochar research Center|access-date=25 April 2016|archive-date=November 5, 2016|archive-url=https://web.archive.org/web/20161105203806/http://www.ierm.ed.ac.uk/homes/sshackle/WP2.pdf|url-status=live}}</ref>{{Better source needed|date=June 2021}}
-===Enhanced weathering===
+==== Enhanced weathering ====
 {{Main|Enhanced weathering}}
 Enhanced weathering is a chemical approach to remove carbon dioxide involving land- or ocean-based techniques. One example of a land-based enhanced weathering technique is in-situ carbonation of silicates. [[Ultramafic rock]], for example, has the potential to store from hundreds to thousands of years' worth of CO<sub>2</sub> emissions, according to estimates.<ref>{{Cite web|url=https://archive.nytimes.com/www.nytimes.com/gwire/2009/03/09/09greenwire-maps-show-rocks-ideal-for-sequestering-carbon-10041.html|title=Maps show rocks ideal for sequestering carbon|website=The New York Times|access-date=2018-05-15|archive-date=May 16, 2018|archive-url=https://web.archive.org/web/20180516103729/https://archive.nytimes.com/www.nytimes.com/gwire/2009/03/09/09greenwire-maps-show-rocks-ideal-for-sequestering-carbon-10041.html|url-status=live}}</ref><ref>{{Cite journal|last=U.S. Department of the Interior|title=Mapping the Mineral Resource Base for Mineral Carbon-Dioxide Sequestration in the Conterminous United States|url=https://pubs.usgs.gov/ds/414/downloads/DS414_text_508.pdf|journal=U.S. Geological Survey|volume=Data Series 414|access-date=May 15, 2018|archive-date=July 27, 2020|archive-url=https://web.archive.org/web/20200727095133/https://pubs.usgs.gov/ds/414/downloads/DS414_text_508.pdf|url-status=live}}</ref> Ocean-based techniques involve alkalinity enhancement, such as grinding, dispersing, and dissolving olivine, limestone, silicates, or calcium hydroxide to address ocean acidification and CO<sub>2</sub> sequestration.<ref>{{Cite web|date=2021-06-23|title=Cloud spraying and hurricane slaying: how ocean geoengineering became the frontier of the climate crisis|url=http://www.theguardian.com/environment/2021/jun/23/cloud-spraying-and-hurricane-slaying-could-geoengineering-fix-the-climate-crisis|access-date=2021-06-23|website=The Guardian|language=en|archive-date=June 23, 2021|archive-url=https://web.archive.org/web/20210623071321/https://www.theguardian.com/environment/2021/jun/23/cloud-spraying-and-hurricane-slaying-could-geoengineering-fix-the-climate-crisis|url-status=live}}</ref> One example of a research project on the feasibility of enhanced weathering is the [[CarbFix]] project in Iceland.<ref>{{Cite web|url=https://www.globalccsinstitute.com/projects/carbfix-sulfix-project|title=CarbFix Project {{!}} Global Carbon Capture and Storage Institute|website=www.globalccsinstitute.com|language=en|access-date=2018-05-15|archive-url=https://web.archive.org/web/20180703133804/https://www.globalccsinstitute.com/projects/carbfix-sulfix-project|archive-date=July 3, 2018|url-status=dead}}</ref><ref>{{Cite news|url=https://www.or.is/english/carbfix/carbfix-project|title=The CarbFix Project|date=2017-08-22|work=www.or.is|access-date=2018-05-15|language=is|archive-date=May 16, 2018|archive-url=https://web.archive.org/web/20180516174158/https://www.or.is/english/carbfix/carbfix-project|url-status=dead}}</ref><ref>{{Cite news|url=https://www.nytimes.com/2015/02/10/science/burying-a-mountain-of-co2.html|title=Turning Carbon Dioxide Into Rock, and Burying It|date=2015-02-09|work=The New York Times|access-date=2018-05-15|language=en-US|issn=0362-4331|archive-date=May 16, 2018|archive-url=https://web.archive.org/web/20180516103143/https://www.nytimes.com/2015/02/10/science/burying-a-mountain-of-co2.html|url-status=live}}</ref>
-===Direct air capture===
+==== Direct air capture ====
 [[File:2010- Direct Air Capture - global - International Energy Agency (IEA) - bar chart.svg|thumb|upright=1.5 | The [[International Energy Agency]] reported growth in [[direct air capture]] global operating capacity.<ref name=IEA_202204>{{cite web |title=Direct Air Capture / A key technology for net zero |url=https://iea.blob.core.windows.net/assets/78633715-15c0-44e1-81df-41123c556d57/DirectAirCapture_Akeytechnologyfornetzero.pdf |website=International Energy Agency (IEA) |archive-url=https://web.archive.org/web/20220410210408/https://iea.blob.core.windows.net/assets/78633715-15c0-44e1-81df-41123c556d57/DirectAirCapture_Akeytechnologyfornetzero.pdf |archive-date=10 April 2022 |page=18 |date=April 2022 |url-status=live }}</ref>]]
 {{Excerpt|Direct air capture}}