- "The process of removing carbon from the atmosphere and depositing it in a reservoir." When carried out deliberately, this may also be referred to as carbon dioxide removal, which is a form of geoengineering.
- The process of carbon capture and storage, where carbon dioxide is removed from flue gases, such as on power stations, before being stored in underground reservoirs.
- Natural biogeochemical cycling of carbon between the atmosphere and reservoirs, such as by chemical weathering of rocks.
Carbon sequestration describes long-term storage of carbon dioxide or other forms of carbon to either mitigate or defer global warming and avoid dangerous climate change. It has been proposed as a way to slow the atmospheric and marine accumulation of greenhouse gases, which are released by burning fossil fuels.
Carbon dioxide is naturally captured from the atmosphere through biological, chemical or physical processes. Some anthropogenic sequestration techniques exploit these natural processes, while some use entirely artificial processes.
Carbon dioxide may be captured as a pure by-product in processes related to petroleum refining or from flue gases from power generation. CO
2 sequestration includes the storage part of carbon capture and storage, which refers to large-scale, permanent artificial capture and sequestration of industrially produced CO
2 using subsurface saline aquifers, reservoirs, ocean water, aging oil fields, or other carbon sinks.
- 1 Biological processes
- 2 Physical processes
- 3 Chemical processes
- 4 Obstruction
- 5 Microbes and drug discovery
- 6 See also
- 7 References
- 8 External links
Biosequestration or carbon sequestration through biological processes affects the global carbon cycle. Examples include major climatic fluctuations, such as the Azolla event, which created the current Arctic climate. Such processes created fossil fuels, as well as clathrate and limestone. By manipulating such processes, geoengineers seek to enhance sequestration.
Reforestation is the replanting of trees on marginal crop and pasture lands to incorporate carbon from atmospheric CO
2 into biomass. For this process to succeed the carbon must not return to the atmosphere from burning or rotting when the trees die. To this end, the trees must grow in perpetuity or the wood from them must itself be sequestered, e.g., via biochar, bio-energy with carbon storage (BECS) or landfill. Short of growth in perpetuity, however, reforestation with long-lived trees (>100 years) will sequester carbon for a more graduated release, minimizing impact during the expected carbon crisis of the 21st century.
Modification of agricultural practices is a recognized method of carbon sequestration as soil can act as an effective carbon sink offsetting as much as 20% of 2010 carbon dioxide emissions annually. (See No-till)
Carbon emission reduction methods in agriculture can be grouped into two categories: reducing and/or displacing emissions and enhancing carbon removal. Some of these reductions involve increasing the efficiency of farm operations (e.g. more fuel-efficient equipment) while some involve interruptions in the natural carbon cycle. Also, some effective techniques (such as the elimination of stubble burning) can negatively impact other environmental concerns (increased herbicide use to control weeds not destroyed by burning).
Increasing yields and efficiency generally reduces emissions as well, since more food results from the same or less effort. Techniques include more accurate use of fertilizers, less soil disturbance, better irrigation, and crop strains bred for locally beneficial traits and increased yields.
Replacing more energy intensive farming operations can also reduce emissions. Reduced or no-till farming requires less machine use and burns correspondingly less fuel per acre. However, no-till usually increases use of weed-control chemicals and the residue now left on the soil surface is more likely to release its CO
2 to the atmosphere as it decays, reducing the net carbon reduction.
In practice, most farming operations that incorporate post-harvest crop residues, wastes and byproducts back into the soil provide a carbon storage benefit. This is particularly the case for practices such as field burning of stubble - rather than releasing almost all of the stored CO
2 to the atmosphere, tillage incorporates the biomass back into the soil where it can be absorbed and a portion of it stored permanently.
Enhancing carbon removal
All crops absorb CO
2 during growth and release it after harvest. The goal of agricultural carbon removal is to use the crop and its relation to the carbon cycle to permanently sequester carbon within the soil. This is done by selecting farming methods that return biomass to the soil and enhance the conditions in which the carbon within the plants will be reduced to its elemental nature and stored in a stable state. Methods for accomplishing this include:
- Use cover crops such as grasses and weeds as temporary cover between planting seasons
- Concentrate livestock in small paddocks for days at a time so they graze lightly but evenly. This encourages roots to grow deeper into the soil. Stock also till the soil with their hooves, grinding old grass and manures into the soil.
- Cover bare paddocks with hay or dead vegetation. This protects soil from the sun and allows the soil to hold more water and be more attractive to carbon-capturing microbes.
- Restore degraded land, which slows carbon release while returning the land to agriculture or other use.
Agricultural sequestration practices may have positive effects on soil, air, and water quality, be beneficial to wildlife, and expand food production. On degraded croplands, an increase of 1 ton of soil carbon pool may increase crop yield by 20 to 40 kilograms per hectare of wheat, 10 to 20 kg/ ha for maize, and 0.5 to 1 kg/ha for cowpeas.
The effects of soil sequestration can be reversed. If the soil is disrupted or tillage practices are abandoned, the soil becomes a net source of greenhouse gases. Typically after 15 to 30 years of sequestration, soil becomes saturated and ceases to absorb carbon. This implies that there is a global limit to the amount of carbon that soil can hold.
Many factors affect the costs of carbon sequestration including soil quality, transaction costs and various externalities such as leakage and unforeseen environmental damage. Because reduction of atmospheric CO
2 is a long-term concern, farmers can be reluctant to adopt more expensive agricultural techniques when there is not a clear crop, soil, or economic benefit. Governments such as Australia and New Zealand are considering allowing farmers to sell carbon credits once they document that they have sufficiently increased soil carbon content.
Ocean iron fertilization is an example of such a geoengineering technique. Iron fertilization attempts to encourage phytoplankton growth, which removes carbon from the atmosphere for at least a period of time. This technique is controversial due to limited understanding its complete effects on the marine ecosystem, including side effects and possibly large deviations from expected behavior. Such effects potentially include release of nitrogen oxides, and disruption of the ocean's nutrient balance.
Natural iron fertilisation events (e.g., deposition of iron-rich dust into ocean waters) can enhance carbon sequestration. Sperm whales act as agents of iron fertilisation when they transport iron from the deep ocean to the surface during prey consumption and defecation. Sperm whales have been shown to increase the levels of primary production and carbon export to the deep ocean by depositing iron rich feces into surface waters of the Southern Ocean. The iron rich feces causes phytoplankton to grow and take up more carbon from the atmosphere. When the phytoplankton dies, some of it sinks to the deep ocean and takes the atmospheric carbon with it. By reducing the abundance of sperm whales in the Southern Ocean, whaling has resulted in an extra 2 million tonnes of carbon remaining in the atmosphere each year.
Australian company Ocean Nourishment Corporation (ONC) plans to sink hundreds of tonnes of urea into the ocean to boost CO
2-absorbing phytoplankton growth as a way to combat climate change. In 2007, Sydney-based ONC completed an experiment involving 1 tonne of nitrogen in the Sulu Sea off the Philippines.
Encouraging various ocean layers to mix can move nutrients and dissolved gases around, offering avenues for geoengineering. Mixing may be achieved by placing large vertical pipes in the oceans to pump nutrient rich water to the surface, triggering blooms of algae, which store carbon when they grow and export carbon when they die. This produces results somewhat similar to iron fertilization. One side-effect is a short-term rise in CO
2, which limits its attractiveness.
Bio-energy with carbon capture and storage (BECCS)
BECCS refers to biomass in power stations and boilers that use carbon capture and storage. The carbon sequestered by the biomass would be captured and stored, thus removing carbon dioxide from the atmosphere.
This technology is sometimes referred to as bio-energy with carbon storage, BECS, though this term can also refer to the carbon sequestration potential in other technologies, such as biochar.
Biochar is charcoal created by pyrolysis of biomass waste. The resulting material is added to a landfill or used as a soil improver to create terra preta. Biogenic carbon is recycled naturally in the carbon cycle. Pyrolysing it to biochar renders the carbon relatively inert so that it remains sequestered in soil. Further, the soil encourages bulking with new organic matter, which gives additional sequestration benefit.[clarification needed]
In the soil, the carbon is unavailable for oxidation to CO
2 and consequential atmospheric release. This is one technique advocated by scientist James Lovelock, creator of the Gaia hypothesis. According to Simon Shackley, "people are talking more about something in the range of one to two billion tonnes a year."
The mechanisms related to biochar are referred to as bio-energy with carbon storage, BECS.
River mouths bring large quantities of nutrients and dead material from upriver into the ocean as part of the process that eventually produces fossil fuels. Transporting material such as crop waste out to sea and allowing it to sink exploits this idea to increase carbon storage. International regulations on marine dumping may restrict or prevent use of this technique.
The first large-scale CO
2 sequestration project which began in 1996 is called Sleipner, and is located in the North Sea where Norway's StatoilHydro strips carbon dioxide from natural gas with amine solvents and disposed of this carbon dioxide in a deep saline aquifer. In 2000, a coal-fueled synthetic natural gas plant in Beulah, North Dakota, became the world's first coal-using plant to capture and store carbon dioxide, at the Weyburn-Midale Carbon Dioxide Project.
2 has been used extensively in enhanced crude oil recovery operations in the United States beginning in 1972. There are in excess of 10,000 wells that inject CO
2 in the state of Texas alone. The gas comes in part from anthropogenic sources, but is principally from large naturally occurring geologic formations of CO
2. It is transported to the oil-producing fields through a large network of over 5,000 kilometres (3,100 mi) of CO
2 pipelines. The use of CO
2 for enhanced oil recovery (EOR) methods in heavy oil reservoirs in the Western Canadian Sedimentary Basin (WCSB) has also been proposed. However, transport cost remains an important hurdle. An extensive CO
2 pipeline system does not yet exist in the WCSB. Athabasca oil sands mining that produces CO
2 is hundreds of kilometers north of the subsurface Heavy crude oil reservoirs that could most benefit from CO
Carbon, in the form of CO
2 can be removed from the atmosphere by chemical processes, and stored in stable carbonate mineral forms. This process is known as 'carbon sequestration by mineral carbonation' or mineral sequestration. The process involves reacting carbon dioxide with abundantly available metal oxides–either magnesium oxide (MgO) or calcium oxide (CaO)–to form stable carbonates. These reactions are exothermic and occur naturally (e.g., the weathering of rock over geologic time periods).
- CaO + CO
2 → CaCO
- MgO + CO
2 → MgCO
4 + 2 CO
2 = 2 MgCO
3 + SiO
4+ 3 CO
2 = 3 MgCO
3 + 2 SiO
2 + 2 H
|Earthen Oxide||Percent of Crust||Carbonate||Enthalpy change
These reactions are slightly more favorable at low temperatures. This process occurs naturally over geologic time frames and is responsible for much of the Earth's surface limestone. The reaction rate can be made faster, for example by reacting at higher temperatures and/or pressures, or by pre-treatment, although this method requires additional energy. One experiment suggests this process is reasonably quick (one year) given porous basaltic rocks.
2 naturally reacts with peridotite rock in surface exposures of ophiolites, notably in Oman. It has been suggested that this process can be enhanced to carry out natural mineralisation of CO
Traditional cement manufacture releases large amounts of carbon dioxide, but newly developed cement types from Novacem can absorb CO
2 from ambient air during hardening. A similar technique was pioneered by TecEco, which has been producing "EcoCement" since 2002.
In Estonia, oil shale ash, generated by power stations could be used as sorbents for CO
2 mineral sequestration. The amount of CO
2 captured averaged 60 to 65% of the carbonaceous CO
2 and 10 to 11% of the total CO
Various carbon dioxide scrubbing processes have been proposed to remove CO
2 from the air, usually using a variant of the Kraft process. Carbon dioxide scrubbing variants exist based on potassium carbonate, which can be used to create liquid fuels, or on sodium hydroxide. These notably include artificial trees proposed by Klaus Lackner to remove carbon dioxide from the atmosphere using chemical scrubbers.
Carbon dioxide sequestration in basalt involves the injecting of CO
2 into deep-sea formations. The CO
2 first mixes with seawater and then reacts with the basalt, both of which are alkaline-rich elements. This reaction results in the release of Ca2+ and Mg2+ ions forming stable carbonate minerals.
Underwater basalt offers a good alternative to other forms of oceanic carbon storage because it has a number of trapping measures to ensure added protection against leakage. These measures include “geothermal, sediment, gravitational and hydrate formation.” Because CO
2 hydrate is denser than CO
2 in seawater, the risk of leakage is minimal. Injecting the CO
2 at depths greater than 2,700 meters (8,900 ft) ensures that the CO
2 has a greater density than seawater, causing it to sink.
One possible injection site is Juan de Fuca plate. Researchers at the Lamont-Doherty Earth Observatory found that this plate at the western coast of the United States has a possible storage capacity of 208 gigatons. This could cover the entire current U.S. carbon emissions for over 100 years.
This process is undergoing tests as part of the CarbFix project.
Carbon dioxide forms carbonic acid when dissolved in water, so ocean acidification is a significant consequence of elevated carbon dioxide levels, and limits the rate at which it can be absorbed into the ocean (the solubility pump). A variety of different bases have been suggested that could neutralize the acid and thus increase CO
2 absorption. For example, adding crushed limestone to oceans enhances the absorption of carbon dioxide. Another approach is to add sodium hydroxide to oceans which is produced by electrolysis of salt water or brine, while eliminating the waste hydrochloric acid by reaction with a volcanic silicate rock such as enstatite, effectively increasing the rate of natural weathering of these rocks to restore ocean pH.
Danger of leaks
Carbon dioxide may be stored deep underground. At depth, hydrostatic pressure acts to keep it in a liquid state. Reservoir design faults, rock fissures and tectonic processes may act to release the gas stored into the ocean or atmosphere.
Some argue that the cost of carbon sequestration would actually increase over time. The use of the technology would add an additional 1-5 cents of cost per kilowatt hour, according to estimate made by the Intergovernmental Panel on Climate Change. The financial costs of modern coal technology would nearly double if use of CCS technology were to be implemented.
The energy requirements of sequestration processes may be significant. In one paper, sequestration consumed 25 percent of the plant's rated 600 megawatt output capacity.
- After adding CO2 capture and compression, the capacity of the coal-fired power plant is reduced to 457 MW.
Microbes and drug discovery
Scientists have recently begun to explore the subterranean environments affiliated with carbon sequestration deep-well drilling operations for unique soil bacteria capable of producing new pharmaceutical leads. Soil microbes have long been a source for effective drugs and new research, such as that conducted at the Center for Pharmaceutical Research and Innovation, suggests subterranean environments to be an untapped source for new discovery.
- Bio-energy with carbon capture and storage
- Blue Carbon
- CarbonFix Standard
- Carbon capture and storage
- Carbon carousel
- Woodland Carbon Code
- Roger Sedjo and Brent Sohngen (2012). "Carbon Sequestration in Forests and Soils". Annual Review of Resource Economics (Annual Reviews) 4: 127–144. doi:10.1146/annurev-resource-083110-115941.
- "Glossary of climate change acronyms". UNFCCC. Retrieved July 15, 2010.
- "Squaring the circle on carbon capture and storage" (PDF). "Claverton Energy Group Conference, Bath,". October 24, 2008. Retrieved May 9, 2010.
- "Energy Terms Glossary S". Nebraska Energy Office. Retrieved May 9, 2010.
- [dead link]
- Richard Lovett (May 3, 2008). "Burying biomass to fight climate change". New Scientist (2654). Retrieved May 9, 2010.(registration required)
- Matthew McDermott (08.22.08). "Can Aerial Reforestation Help Slow Climate Change? Discovery Project Earth Examines Re-Engineering the Planet’s Possibilities". TreeHugger. Retrieved May 9, 2010. Check date values in:
- Nelson, Robert (July 1999). "Carbon Sequestration: A Better Alternative for Climate Change?".[dead link]
- Batjes, Niels H. (1996). "Total carbon and nitrogen in the soils of the world". European Journal of Soil Science 47 (2): 151–163. doi:10.1111/j.1365-2389.1996.tb01386.x.
- Pete Smith. "Soil Organic Carbon Dynamics and Land-Use Change". In Ademola K. Braimoh. Land Use and Soil Resources. Springer. ISBN 1-4020-6777-1.
- "FACTBOX: Carbon farming on rise in Australia". Reuters. June 16, 2009. Retrieved May 9, 2010.
- Sundermeiera A, Islam K, Rautb Y, Reederc R, and Dickd W. (September 2010). "Continuous No-Till Impacts on Soil Biophysical Carbon Sequestration". Soil Science Society of America Journal 75 (5): 1779–1788. doi:10.2136/sssaj2010.0334.
- Smith P, Martino D, Cai Z, et al. (February 2008). "Greenhouse gas mitigation in agriculture". Philos. Trans. R. Soc. Lond., B, Biol. Sci. 363 (1492): 789–813. doi:10.1098/rstb.2007.2184. PMC 2610110. PMID 17827109. |p 807, 790—793.
- "Environmental Co Benefits of Sequestration Practices. 2006. June 1, 2009. http://www.epa.gov/sequestration/co-benefits.html
- Lal, R. (June 2009). "Soil Carbon Sequestration Impacts on Global Climate Change and Food Security". Science 304 (5677): 1623–1627. Bibcode:2004Sci...304.1623L. doi:10.1126/science.1097396. PMID 15192216. “Addressing Reversibility (Duration) for Projects. US Environmental Protection Agency. 2006. June 1, 2009 < http://www.epa.gov/sequestration/duration.html>
- Renwick, A; Ball, A; Pretty, J.N. (August 2002). "Biological and Policy Constraints on the Adoption of Carbon Farming in Temperate Regions". Phil. Trans. R. Soc. Lond. A 360 (1797): 1721–40. Bibcode:2002RSPTA.360.1721R. doi:10.1098/rsta.2002.1028. PMID 12460494. pp. 1722, 1726—9.
- Gerald Traufetter (01/02/2009). "Cold Carbon Sink: Slowing Global Warming with Antarctic Iron". Spiegel.de. Retrieved May 9, 2010. Check date values in:
- X. Jin; N. Gruber; H. Frenzel1; S. C. Doney; J. C. McWilliams (2008). "The impact on atmospheric CO
2 of iron fertilization induced changes in the ocean's biological pump" 5. Biogeosciences. pp. 385–406. Retrieved May 9, 2010.
- Richard Monastersky (September 30, 1995). "Iron versus the Greenhouse - Oceanographers cautiously explore a global warming therapy". Science News. Retrieved May 9, 2010.
- "WWF condemns Planktos Inc. iron-seeding plan in the Galapagos". Biopact.com. June 27, 2007. Retrieved May 9, 2010.
- David Fogarty (December 15, 2008). "Reuters AlertNet -RPT-FEATURE-Scientists urge caution in ocean-CO
2 capture schemes". Alertnet.org. Retrieved May 9, 2010.
- Lavery T.J. et al. (2010). "Iron defecation by sperm whales stimulates carbon export in the Southern Ocean". Proceedings of the Royal Society B 277: 3527–3531. doi:10.1098/rspb.2010.0863. PMC 2982231. PMID 20554546.
- Anna Salleh (November 9, 2007). "Urea 'climate solution' may backfire". Australian Broadcasting Commission. Retrieved May 9, 2010.
- Lovelock JE; Rapley CG (September 27, 2007). "Ocean pipes could help the earth to cure itself". Nature 449 (7161): 403. Bibcode:2007Natur.449..403L. doi:10.1038/449403a. PMID 17898747.
- Fred Pearce (September 26, 2007). "Ocean pumps could counter global warming". New Scientist. Retrieved May 9, 2010.
- Duke J. (2008). "A proposal to force vertical mixing of the Pacific Equatorial Undercurrent to create a system of equatorially trapped coupled convection that counteracts global warming". Geophysical Research Abstracts. John H. Duke (September 5, 2007). "A proposal to force vertical mixing of the Pacific Equatorial Undercurrent to create a system of equatorially trapped coupled convection that counteracts global warming" (PDF). Retrieved May 9, 2010.
- Dutreuil, S; Bopp, L; Tagliabue, A (2009). "Impact of enhanced vertical mixing on marine biogeochemistry: lessons for geo-engineering and natural variability". Biogeosciences (European Geosciences Union) 6: 901–912. doi:10.5194/bg-6-901-2009.
- Fisher, B.S.; et al. (2007). "Issues related to mitigation in the long term context, In Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Inter-governmental Panel on Climate Change". Fourth Assessment Report of the Inter-governmental Panel on Climate Change. Cambridge University Press.
- Obersteiner, M., Ch. Azar, P. Kauppi, K. Möllersten, J. Moreira, S.Nilsson, P. Read, K. Riahi, B. Schlamadinger, Y. Yamagata, J. Yan, and J.-P. van Ypersele (2001). "Managing climate risk". Science 294 (5543): 786–7. doi:10.1126/science.294.5543.786b. PMID 11681318.
- Christian Azar, et al. (January 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. doi:10.1007/s10584-005-3484-7.
- Ning Zeng (2008). "Carbon sequestration via wood burial". Carbon Balance and Management 3 (1): 1. doi:10.1186/1750-0680-3-1. PMC 2266747. PMID 18173850.
- Richard Lovett (May 3, 2008). "Burying biomass to fight climate change". New Scientist (2654). Retrieved May 9, 2010.(subscription required)
- Lehmann, J., Gaunt, J., Rondon, M. (2006). "Bio-char sequestration in terrestrial ecosystems – a review". Mitigation and Adaptation Strategies for Global Change 11: 403–427. doi:10.1007/s11027-005-9006-5.
- "International Biochar Initiative | International Biochar Initiative". Biochar-international.org. Retrieved May 9, 2010.
- Gaia Vince (January 23, 2009). "One last chance to save mankind". New Scientist. Retrieved May 9, 2010.(subscription required)
- Harvey, Fiona (February 27, 2009). "Black is the new green". Financial Times. Retrieved March 4, 2009.
- Stuart E. Strand; Benford, Gregory (January 12, 2009). "Ocean Sequestration of Crop Residue Carbon: Recycling Fossil Fuel Carbon Back to Deep Sediments". Environmental Science & Technology 43 (4): 1000. Bibcode:2009EnST...43.1000S. doi:10.1021/es8015556.
- "World’s first network of demonstration projects, all of which are aiming to be operational by 2015 and commercially viable CCS by 2020". Ccsnetwork.eu. Retrieved February 22, 2012.
- "Weyburn-Midale CO
2 Project, World’s first CO
2 measuring, monitoring and verification initiative". Petroleum Technology Research Centre. Retrieved April 9, 2009.
-  Squaring the circle - carbon capture and storage - Chris Hodrien - Claverton Energy Conference, Bath, 2008
- "Subscription Verification". Dailyoilbulletin.com. Retrieved May 9, 2010.
- Bouwman, Elisabeth; Angamuthu, Raja; Byers, Philip; Lutz, Martin; Spek, Anthony L. (July 15, 2010). "Electrocatalytic CO2 Conversion to Oxalate by a Copper Complex". Science 327 (5393): 313–315. doi:10.1126/science.1177981. Retrieved 26 September 2014.
- Herzog, Howard (March 14, 2002). "Carbon Sequestration via Mineral Carbonation: Overview and Assessment" (PDF). Massachusetts Institute of Technology. Retrieved March 5, 2009.
- Goldberg, Philip; Zhong-Ying Chen; O'Connor, William; Walters, Richard; Ziock Hans (1998). "CO
2 Mineral Sequestration Studies in US" (PDF). National Energy Technology Laboratory. Retrieved March 6, 2009.
- Yirka, Bob. "Researchers find carbon reactions with basalt can form carbonate minerals faster than thought". Phys,org. Omicron Technology Ltd. Retrieved 25 April 2014.
- Peter B. Kelemen1 and Jürg Matter (November 3, 2008). "In situ carbonation of peridotite for CO
2 storage". Proc. Natl. Acad. Sci. U.S.A. 105 (45): 17295–300. Bibcode:2008PNAS..10517295K. doi:10.1073/pnas.0805794105.
- Timothy Gardner (November 7, 2008). "Scientists say a rock can soak up carbon dioxide | Reuters". Uk.reuters.com. Retrieved May 9, 2010.
- "Novacem". Imperial Innovations. May 6, 2008. Retrieved May 9, 2010.
- Jha, Alok (December 31, 2008). "Revealed: The cement that eats carbon dioxide". The Guardian (London). Retrieved April 3, 2010.
- "Home". TecEco. July 1, 1983. Retrieved May 9, 2010.
- Uibu, Mai; Uus, Mati; Kuusik, Rein (February 2008). "CO
2 mineral sequestration in oil-shale wastes from Estonian power production". Journal of Environmental Management 90 (2): 1253–60. doi:10.1016/j.jenvman.2008.07.012. PMID 18793821.
- Chang, Kenneth (February 19, 2008). "Scientists Would Turn Greenhouse Gas Into Gasoline". The New York Times. Retrieved April 3, 2010.
- Frank Zeman (2007). "Energy and Material Balance of CO2 Capture from Ambient Air" (PDF). Environ. Sci. Technol. 41 (21): 7558–63. Bibcode:2007EnST...41.7558Z. doi:10.1021/es070874m. PMID 18044541.
- "Chemical 'sponge' could filterCO
2 from the air". New Scientist. October 3, 2007. Retrieved May 9, 2010.
- "New Device Vacuums Away Carbon Dioxide". LiveScience. May 1, 2007. Retrieved May 9, 2010.
- Adam, David (May 31, 2008). "Could US scientist's 'CO
2 catcher' help to slow warming?". The Guardian (London). Retrieved April 3, 2010.
- David S. Goldberg, Taro Takahashi, and Angela L. Slagle (2008). "Carbon dioxide sequestration in deep-sea basalt". Proc. Natl. Acad. Sci. U.S.A. 105 (29): 9920–5. Bibcode:2008PNAS..105.9920G. doi:10.1073/pnas.0804397105. PMC 2464617. PMID 18626013.
- "Carbon storage in undersea basalt offers extra security". environmentalresearchweb. July 15, 2008. Retrieved May 9, 2010.
- Kheshgi, H. S. (1995). "Sequestering atmospheric carbon dioxide by increasing ocean alkalinity". Energy 20 (9): 915–922. doi:10.1016/0360-5442(95)00035-F.
- K.S. Lackner, C.H. Wendt, D.P. Butt, E.L. Joyce and D.H. Sharp (1995). "Carbon dioxide disposal in carbonate minerals". Energy 20 (11): 1153–70. doi:10.1016/0360-5442(95)00071-N.
- K.S. Lackner, D.P. Butt, C.H. Wendt (1997). "Progress on binding CO
2 in mineral substrates". Energy Conversion and Management 38: S259–S264. doi:10.1016/S0196-8904(96)00279-8.
- Rau, G.H., Caldeira, K. (1999). "Enhanced carbonate dissolution: A means of sequestering waste CO
2 as ocean bicarbonate". Energy Conversion and Management 40 (17): 1803–13. doi:10.1016/S0196-8904(99)00071-0.
- Rau, G.H., K.G. Knauss, W.H. Langer, K. Caldeira (2007). "Reducing energy-related CO
2 emissions using accelerated weathering of limestone". Energy 32 (8): 1471–7. doi:10.1016/j.energy.2006.10.011.
- Harvey, L.D.D. (2008). "Mitigating the atmospheric CO
2 increase and ocean acidification by adding limestone powder to upwelling regions". Journal of Geophysical Research 113: C04028. Bibcode:2008JGRC..11304028H. doi:10.1029/2007JC004373.
- "Scientists enhance Mother Nature's carbon handling mechanism". Penn State Live. November 7, 2007.
- Kurt Zenz House, Christopher H. House, Daniel P. Schrag and Michael J. Aziz (2007). "Electrochemical Acceleration of Chemical Weathering as an Energetically Feasible Approach to Mitigating Anthropogenic Climate Change". Environ. Sci. Technol. 41 (24): 8464–8470. Bibcode:2007EnST...41.8464H. doi:10.1021/es0701816. PMID 18200880.
- Clover, Charles (November 7, 2007). "Global warming 'cure' found by scientists". The Daily Telegraph (London). Retrieved April 3, 2010.
- DeMonte, Adena. "The Cost of Carbon Capture." July 2007.
- Dias, DA; Urban, S; Roessner, U (Apr 16, 2012). "A historical overview of natural products in drug discovery.". Metabolites 2 (2): 303–36. PMID 24957513.
- Wang, X; Shaaban, KA; Elshahawi, SI; Ponomareva, LV; Sunkara, M; Copley, GC; Hower, JC; Morris, AJ; Kharel, MK; Thorson, JS (Aug 2014). "Mullinamides A and B, new cyclopeptides produced by the Ruth Mullins coal mine fire isolate Streptomyces sp. RM-27-46.". The Journal of antibiotics 67 (8): 571–5. PMID 24713874.
- Wang, X; Elshahawi, SI; Shaaban, KA; Fang, L; Ponomareva, LV; Zhang, Y; Copley, GC; Hower, JC; Zhan, CG; Kharel, MK; Thorson, JS (Jan 17, 2014). "Ruthmycin, a new tetracyclic polyketide from Streptomyces sp. RM-4-15.". Organic letters 16 (2): 456–9. PMID 24341358.
- Research Program on Carbon Sequestration at the Cluster of Excellence "Future Ocean", Kiel
- Carbon Sequestration Leadership Forum International carbon capture and storage initiative.
- Scottish Centre for Carbon Storage Research Carbon Capture and Storage Research in Edinburgh, Scotland.
- UK Carbon Capture and Storage Consortium Overview of the UK academic consortium focused on researching issues related to Carbon Capture and Storage.
- Sieves put a lid on greenhouse gas
- The capture, utilization and disposal of carbon dioxide from fossil fuel-fired power plants.
- Carbon Capture and Storage Information Center (Chinese + English)
- Carbon Sequestration: Science, Technology, and Policy MIT program covers carbon capture and storage (CCS)
- Sequestration with Enhanced Coal Bed Methane Recovery
- Link to video, UK Looks for Natural Products in Kentucky's Unique Environments