Climate engineering
Climate engineering (or geoengineering) is an umbrella term for both carbon dioxide removal and solar radiation modification, when applied at a planetary scale.[1]: 168 However, these two processes have very different characteristics. For this reason, the Intergovernmental Panel on Climate Change no longer uses this overarching term.[1]: 168 [2] Carbon dioxide removal approaches are part of climate change mitigation. Solar radiation modification is reflecting some sunlight (solar radiation) back to space.[3] Some publications place passive radiative cooling into the climate engineering category. This technology increases the Earth's thermal emittance.[4][5][6] The media tends to use climate engineering also for other technologies such as glacier stabilization, ocean liming, and iron fertilization of oceans. The latter would modify carbon sequestration processes that take place in oceans.
Some types of climate engineering are highly controversial due to the large uncertainties around effectiveness, side effects and unforeseen consequences.[7] Interventions at large scale run a greater risk of unintended disruptions of natural systems, resulting in a dilemma that such disruptions might be more damaging than the climate damage that they offset.[8] However, the risks of such interventions must be seen in the context of the trajectory of climate change without them.[8][9]
The Union of Concerned Scientists points to the danger that the use of climate engineering technology will become an excuse not to address the root causes of climate change, slow our emissions reductions and start moving toward a low-carbon economy.[10]
Terminology
[edit]Climate engineering (or geoengineering) has been used as an umbrella term for both carbon dioxide removal and solar radiation management, when applied at a planetary scale.[1]: 168 However, these two methods have very different geophysical characteristics, which is why the Intergovernmental Panel on Climate Change no longer uses this term.[1]: 168 [2] This decision was communicated in around 2018, see for example the "Special Report on Global Warming of 1.5 °C".[11]: 550
According to climate economist Gernot Wagner the term geoengineering is "largely an artefact and a result of the term's frequent use in popular discourse" and "so vague and all-encompassing as to have lost much meaning".[7]: 14
Specific technologies that fall into the "climate engineering" umbrella term include:[12]: 30
- Carbon dioxide removal
- Biochar: Biochar is a high-carbon, fine-grained residue that is produced via pyrolysis[13]
- Bioenergy with carbon capture and storage (BECCS): the process of extracting bioenergy from biomass and capturing and storing the carbon, thereby removing it from the atmosphere.[14]
- Direct air capture and carbon storage: a process of capturing carbon dioxide directly from the ambient air (as opposed to capturing from point sources, such as a cement factory or biomass power plant) and generating a concentrated stream of CO2 for sequestration or utilization or production of carbon-neutral fuel and windgas.
- Enhanced weathering: a process that aims to accelerate the natural weathering by spreading finely ground silicate rock, such as basalt, onto surfaces which speeds up chemical reactions between rocks, water, and air. It also removes carbon dioxide (CO2) from the atmosphere, permanently storing it in solid carbonate minerals or ocean alkalinity.[15] The latter also slows ocean acidification.
- Solar Radiation Management
- Marine cloud brightening: a proposed technique that would make clouds brighter, reflecting a small fraction of incoming sunlight back into space in order to offset anthropogenic global warming.[16]
- Mirrors in space (MIS): satellites that are designed to change the amount of solar radiation that impacts the Earth as a form of climate engineering. Since the conception of the idea in 1923, 1929, 1957 and 1978 (Hermann Oberth) and also in the 1980s, space mirrors have mainly been theorized as a way to deflect sunlight to counter global warming and were seriously considered in the 2000s.[17][18][19][20][21][22]
- Stratospheric aerosol injection (SAI): a proposed method to introduce aerosols into the stratosphere to create a cooling effect via global dimming and increased albedo, which occurs naturally from volcanic eruptions.[23]
The following methods are not termed climate engineering in the latest IPCC assessment report in 2022[1]: 6–11 but are included under this umbrella term by other publications on this topic:[24][7]
- Passive daytime radiative cooling
- Ground-level albedo modification: a process of increasing Earth's albedo through the means of altering things on the Earth's surface. Examples include planting light-colored plants to help with reflecting sunlight back into space.[25]
- Glacier stabilization: proposals aiming to slow down or prevent sea level rise caused by the collapse of notable marine-terminating glaciers, such as Jakobshavn Glacier in Greenland or Thwaites Glacier and Pine Island Glacier in Antarctica. It may be possible to bolster some glaciers directly,[26] but blocking the flow of ever-warming ocean water at a distance, allowing it more time to mix with the cooler water around the glacier, is likely to be far more effective.[27][28][29]
- Ocean geoengineering[30] (adding material such as lime or iron to the ocean to affect its ability to sequester carbon dioxide)
Technologies
[edit]Carbon dioxide removal
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/4/46/Tree_planting_closeup.jpg/220px-Tree_planting_closeup.jpg)
Carbon dioxide removal (CDR) is a process in which carbon dioxide (CO2) is removed from the atmosphere by deliberate human activities and durably stored in geological, terrestrial, or ocean reservoirs, or in products.[33]: 2221 This process is also known as carbon removal, greenhouse gas removal or negative emissions. CDR is more and more often integrated into climate policy, as an element of climate change mitigation strategies.[34][35] Achieving net zero emissions will require first and foremost deep and sustained cuts in emissions, and then—in addition—the use of CDR ("CDR is what puts the net into net zero emissions"[36]). In the future, CDR may be able to counterbalance emissions that are technically difficult to eliminate, such as some agricultural and industrial emissions.[37]: 114
CDR includes methods that are implemented on land or in aquatic systems. Land-based methods include afforestation, reforestation, agricultural practices that sequester carbon in soils (carbon farming), bioenergy with carbon capture and storage (BECCS), and direct air capture combined with storage.[37]: 115 There are also CDR methods that use oceans and other water bodies. Those are called ocean fertilization, ocean alkalinity enhancement,[38] wetland restoration and blue carbon approaches.[37]: 115 A detailed analysis needs to be performed to assess how much negative emissions a particular process achieves. This analysis includes life cycle analysis and "monitoring, reporting, and verification" (MRV) of the entire process.[39] Carbon capture and storage (CCS) are not regarded as CDR because CCS does not reduce the amount of carbon dioxide already in the atmosphere.Solar radiation modification
[edit]![refer to caption and image description](http://upload.wikimedia.org/wikipedia/commons/thumb/f/f7/SPICE_SRM_overview.jpg/320px-SPICE_SRM_overview.jpg)
Solar radiation modification (SRM), or solar geoengineering, refers to a range of approaches to limit global warming by increasing the amount of sunlight (solar radiation) that the atmosphere reflects back to space or by reducing the trapping of outgoing thermal radiation. Among the multiple potential approaches, stratospheric aerosol injection is the most-studied, followed by marine cloud brightening. SRM could be a temporary measure to limit climate-change impacts while greenhouse gas emissions are reduced and carbon dioxide is removed,[40] but would not be a substitute for reducing emissions. SRM is a form of climate engineering.
Multiple authoritative international scientific assessments, based on evidence from climate models and natural analogues, have generally shown that some forms of SRM could reduce global warming and many adverse effects of climate change.[41][42][43] Specifically, controlled stratospheric aerosol injection appears able to greatly moderate most environmental impacts—especially warming—and consequently most ecological, economic, and other impacts of climate change across most regions. However, because warming from greenhouse gases and cooling from SRM would operate differently across latitudes and seasons, a world where global warming would be offset by SRM would have a different climate from one where this warming did not occur in the first place. Furthermore, confidence in the current projections of how SRM would affect regional climate and ecosystems is low.[40]Passive daytime radiative cooling
[edit]Enhancing the thermal emissivity of Earth through passive daytime radiative cooling has been proposed as an alternative or "third approach" to climate engineering[4][44] that is "less intrusive" and more predictable or reversible than stratospheric aerosol injection.[45]
![](http://upload.wikimedia.org/wikipedia/commons/thumb/c/c3/Passive_daytime_radiative_cooling_diagram.jpg/220px-Passive_daytime_radiative_cooling_diagram.jpg)
Ocean geoengineering
[edit]Ocean geoengineering involves modifying the ocean to reduce the impacts of rising temperature. One approach is to add material such as lime or iron to the ocean to increase its ability to support marine life and/or sequester CO
2. In 2021 the US National Academies of Sciences, Engineering, and Medicine (NASEM) requested $2.5 billion funds for research in the following decade, specifically including field tests.[30]
Another idea is to reduce sea level rise by installing underwater "curtains" to protect Antarctic glaciers from warming waters, or by drilling holes in ice to pump out water and heat.[59]
Ocean liming
[edit]Enriching seawater with calcium hydroxide (lime) has been reported to lower ocean acidity, which reduces pressure on marine life such as oysters and absorb CO
2. The added lime raised the water's pH, capturing CO
2 in the form of calcium bicarbonate or as carbonate deposited in mollusk shells. Lime is produced in volume for the cement industry.[30] This was assessed in 2022 in an experiment in Apalachicola, Florida in an attempt to halt declining oyster populations. pH levels increased modestly, as CO
2 was reduced by 70 ppm.[30]
A 2014 experiment added sodium hydroxide (lye) to part of Australia's Great Barrier Reef. It raised pH levels to nearly preindustrial levels.[30]
However, producing alkaline materials typically releases large amounts of CO
2, partially offsetting the sequestration. Alkaline additives become diluted and dispersed in one month, without durable effects, such that if necessary, the program could be ended without leaving long-term effects.[30]
Ocean sulfur cycle enhancement
[edit]Enhancing the natural marine sulfur cycle by fertilizing a small portion with iron—typically considered to be a greenhouse gas remediation method—may also increase the reflection of sunlight.[60][61] Such fertilization, especially in the Southern Ocean, would enhance dimethyl sulfide production and consequently cloud reflectivity. This could potentially be used as regional SRM, to slow Antarctic ice from melting.[citation needed] Such techniques also tend to sequester carbon, but the enhancement of cloud albedo also appears to be a likely effect.
Iron fertilization
[edit]Submarine forest
[edit]Another 2022 experiment attempted to sequester carbon using giant kelp planted off the Namibian coast.[30] Whilst this approach has been called ocean geoengineering by the researchers it is just another form of carbon dioxide removal via sequestration. Another term that is used to describe this process is blue carbon management and also marine geoengineering.
Glacier stabilization
[edit]![](http://upload.wikimedia.org/wikipedia/commons/thumb/2/25/Wolovick2018_Thwaites_sill_timelines.png/220px-Wolovick2018_Thwaites_sill_timelines.png)
Some engineering interventions have been proposed for Thwaites Glacier and the nearby Pine Island Glacier to physically stabilize its ice or to preserve it. These interventions would block the flow of warm ocean water, which currently renders the collapse of these two glaciers practically inevitable even without further warming.[62][63] A proposal from 2018 included building sills at the Thwaites' grounding line to either physically reinforce it, or to block some fraction of warm water flow. The former would be the simplest intervention, yet equivalent to "the largest civil engineering projects that humanity has ever attempted". It is also only 30% likely to work. Constructions blocking even 50% of the warm water flow are expected to be far more effective, yet far more difficult as well.[64] Some researchers argued that this proposal could be ineffective, or even accelerate sea level rise.[65] The authors of the original proposal suggested attempting this intervention on smaller sites, like the Jakobshavn Glacier in Greenland, as a test.[64][63] They also acknowledged that this intervention cannot prevent sea level rise from the increased ocean heat content, and would be ineffective in the long run without greenhouse gas emission reductions.[64]
In 2023, it was proposed that an installation of underwater curtains, made of a flexible material and anchored to the Amundsen Sea floor would be able to interrupt warm water flow. This approach would reduce costs and increase the longevity of the material (conservatively estimated at 25 years for curtain elements and up to 100 years for the foundations) relative to more rigid structures. With them in place, Thwaites Ice Shelf and Pine Island Ice Shelf would presumably regrow to a state they last had a century ago, thus stabilizing these glaciers.[66][67][63] To achieve this, the curtains would have to be placed at a depth of around 600 metres (0.37 miles) (to avoid damage from icebergs which would be regularly drifting above) and be 80 km (50 mi) long. The authors acknowledged that while work on this scale would be unprecedented and face many challenges in the Antarctic (including polar night and the currently insufficient numbers of specialized polar ships and underwater vessels), it would also not require any new technology and there is already experience of laying down pipelines at such depths.[66][67]Problems
[edit]Interventions at large scale run a greater risk of unintended disruptions of natural systems, resulting in a dilemma that such disruptions might be more damaging than the climate damage that they offset.[8]
Ethical aspects
[edit]Climate engineering may reduce the urgency of reducing carbon emissions, a form of moral hazard.[68] Also, most efforts have only temporary effects, which implies rapid rebound if they are not sustained.[69] The Union of Concerned Scientists points to the danger that the use of climate engineering technology will become an excuse not to address the root causes of climate change, slow our emissions reductions and start moving toward a low-carbon economy.[10] However, several public opinion surveys and focus groups reported either a desire to increase emission cuts in the presence of climate engineering, or no effect.[70][71][72] Other modelling work suggests that the prospect of climate engineering may in fact increase the likelihood of emissions reduction.[73][74][75][76]
If climate engineering can alter the climate, then this raises questions whether humans have the right to deliberately change the climate, and under what conditions. For example, using climate engineering to stabilize temperatures is not the same as doing so to optimize the climate for some other purpose. Some religious traditions express views on the relationship between humans and their surroundings that encourage (to conduct responsible stewardship) or discourage (to avoid hubris) explicit actions to affect climate.[77]
Society and culture
[edit]Public perception
[edit]A large 2018 study used an online survey to investigate public perceptions of six climate engineering methods in the United States, United Kingdom, Australia, and New Zealand.[12] Public awareness of climate engineering was low; less than a fifth of respondents reported prior knowledge. Perceptions of the six climate engineering methods proposed (three from the carbon dioxide removal group and three from the solar radiation modification group) were largely negative and frequently associated with attributes like 'risky', 'artificial' and 'unknown effects'. Carbon dioxide removal methods were preferred over solar radiation modification. Public perceptions were remarkably stable with only minor differences between the different countries in the surveys.[12][78]
Some environmental organizations (such as Friends of the Earth and Greenpeace) have been reluctant to endorse or oppose solar radiation modification, but are often more supportive of nature-based carbon dioxide removal projects, such as afforestation and peatland restoration.[68][79]
Research and projects
[edit]Several organizations have investigated climate engineering with a view to evaluating its potential, including the US Congress,[80] the US National Academy of Sciences, Engineering, and Medicine,[81] the Royal Society,[82] the UK Parliament,[83] the Institution of Mechanical Engineers,[84] and the Intergovernmental Panel on Climate Change.
In 2009, the Royal Society in the UK reviewed a wide range of proposed climate engineering methods and evaluated them in terms of effectiveness, affordability, timeliness, and safety (assigning qualitative estimates in each assessment). The key recommendations reports were that "Parties to the UNFCCC should make increased efforts towards mitigating and adapting to climate change, and in particular to agreeing to global emissions reductions", and that "[nothing] now known about geoengineering options gives any reason to diminish these efforts".[85] Nonetheless, the report also recommended that "research and development of climate engineering options should be undertaken to investigate whether low-risk methods can be made available if it becomes necessary to reduce the rate of warming this century".[85]
In 2009, a review examined the scientific plausibility of proposed methods rather than the practical considerations such as engineering feasibility or economic cost. The authors found that "[air] capture and storage shows the greatest potential, combined with afforestation, reforestation and bio-char production", and noted that "other suggestions that have received considerable media attention, in particular, "ocean pipes" appear to be ineffective".[86] They concluded that "[climate] geoengineering is best considered as a potential complement to the mitigation of CO2 emissions, rather than as an alternative to it".[86]
The IMechE report examined a small subset of proposed methods (air capture, urban albedo and algal-based CO2 capture techniques), and its main conclusions in 2011 were that climate engineering should be researched and trialed at the small scale alongside a wider decarbonization of the economy.[84]
In 2015, the US National Academy of Sciences, Engineering, and Medicine concluded a 21-month project to study the potential impacts, benefits, and costs of climate engineering. The differences between these two classes of climate engineering "led the committee to evaluate the two types of approaches separately in companion reports, a distinction it hopes carries over to future scientific and policy discussions."[87][88][89] The resulting study titled Climate Intervention was released in February 2015 and consists of two volumes: Reflecting Sunlight to Cool Earth[90] and Carbon Dioxide Removal and Reliable Sequestration.[91]
In June 2023 the US government released a report that recommended conducting research on stratospheric aerosol injection and marine cloud brightening.[92]
As of 2024 the Coastal Atmospheric Aerosol Research and Engagement (CAARE) project was launching sea salt into the marine sky in an effort to increase cloud "brightness" (reflective capacity). The sea salt is launched from the USS Hornet Sea, Air & Space Museum (based on the project's regulatory filings).[93]
See also
[edit]References
[edit]- ^ a b c d e IPCC (2022) Chapter 1: Introduction and Framing in Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA
- ^ a b 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.
- ^ National Academies of Sciences, Engineering (2021-03-25). Reflecting Sunlight: Recommendations for Solar Geoengineering Research and Research Governance. doi:10.17226/25762. ISBN 978-0-309-67605-2. S2CID 234327299. Archived from the original on 2021-04-17. Retrieved 2021-04-17.
- ^ a b Zevenhovena, Ron; Fält, Martin (June 2018). "Radiative cooling through the atmospheric window: A third, less intrusive geoengineering approach". Energy. 152 – via Elsevier Science Direct.
An alternative, third geoengineering approach would be enhanced cooling by thermal radiation from the Earth's surface into space.
- ^ Wang, Tong; Wu, Yi; Shi, Lan; Hu, Xinhua; Chen, Min; Wu, Limin (2021). "A structural polymer for highly efficient all-day passive radiative cooling". Nature Communications. 12 (365): 365. doi:10.1038/s41467-020-20646-7. PMC 7809060. PMID 33446648.
One possibly alternative approach is passive radiative cooling—a sky-facing surface on the Earth spontaneously cools by radiating heat to the ultracold outer space through the atmosphere's longwave infrared (LWIR) transparency window (λ ~ 8–13 μm).
- ^ Chen, Meijie; Pang, Dan; Chen, Xingyu; Yan, Hongjie; Yang, Yuan (2022). "Passive daytime radiative cooling: Fundamentals, material designs, and applications". EcoMat. 4. doi:10.1002/eom2.12153. S2CID 240331557.
Passive daytime radiative cooling dissipates terrestrial heat to the extremely cold outer space without using any energy input or producing pollution. It has the potential to simultaneously alleviate the two major problems of energy crisis and global warming.
- ^ a b c Gernot Wagner (2021). Geoengineering: the Gamble.
- ^ a b c Matthias Honegger; Axel Michaelowa; Sonja Butzengeiger-Geyer (2012). Climate Engineering – Avoiding Pandora's Box through Research and Governance (PDF). FNI Climate Policy Perspectives. Fridtjof Nansen Institute (FNI), Perspectives. Archived from the original (PDF) on 2015-09-06. Retrieved 2018-10-09.
- ^ Zahra Hirji (October 6, 2016). "Removing CO2 From the Air Only Hope for Fixing Climate Change, New Study Says; Without 'negative emissions' to help return atmospheric CO2 to 350 ppm, future generations could face costs that 'may become too heavy to bear,' paper says". insideclimatenews.org. InsideClimate News. Archived from the original on November 17, 2019. Retrieved October 7, 2016.
- ^ a b "What Is Solar Geoengineering?". The Union of Concerned Scientists. Dec 4, 2020.
- ^ Global Warming of 1.5°C: IPCC Special Report on impacts of global warming of 1.5°C above pre-industrial levels in context of strengthening response to climate change, sustainable development, and efforts to eradicate poverty (1 ed.). Cambridge University Press. 2022. doi:10.1017/9781009157940.008. ISBN 978-1-009-15794-0.
- ^ a b c Carlisle, Daniel P.; Feetham, Pamela M.; Wright, Malcolm J.; Teagle, Damon A. H. (2020-04-12). "The public remain uninformed and wary of climate engineering" (PDF). Climatic Change. 160 (2): 303–322. Bibcode:2020ClCh..160..303C. doi:10.1007/s10584-020-02706-5. ISSN 1573-1480. S2CID 215731777. Archived (PDF) from the original on 2021-06-14. Retrieved 2021-05-18.
- ^ Dominic Woolf; James E. Amonette; F. Alayne Street-Perrott; Johannes Lehmann; Stephen Joseph (August 2010). "Sustainable biochar to mitigate global climate change". Nature Communications. 1 (5): 56. Bibcode:2010NatCo...1...56W. doi:10.1038/ncomms1053. ISSN 2041-1723. PMC 2964457. PMID 20975722.
- ^ Obersteiner, M. (2001). "Managing Climate Risk". Science. 294 (5543): 786–7. doi:10.1126/science.294.5543.786b. PMID 11681318. S2CID 34722068.
- ^ "Guest post: How 'enhanced weathering' could slow climate change and boost crop yields". Carbon Brief. 2018-02-19. Archived from the original on 2021-09-08. Retrieved 2021-11-03.
- ^ Committee on Geoengineering Climate: Technical Evaluation and Discussion of Impacts; Board on Atmospheric Sciences and Climate; Ocean Studies Board; Division on Earth and Life Studies; National Research Council (2015). Climate Intervention: Reflecting Sunlight to Cool Earth. National Academies Press. ISBN 978-0-309-31482-4. Archived from the original on 2019-12-14. Retrieved 2016-10-21.
- ^ Oberth, Hermann (1984) [1923]. Die Rakete zu den Planetenräumen (in German). Michaels-Verlag Germany. pp. 87–88.
- ^ Oberth, Hermann (1970) [1929]. ways to spaceflight. NASA. pp. 177–506. Retrieved 21 December 2017 – via archiv.org.
- ^ Oberth, Hermann (1957). Menschen im Weltraum (in German). Econ Duesseldorf Germany. pp. 125–182.
- ^ Oberth, Hermann (1978). Der Weltraumspiegel (in German). Kriterion Bucharest.
- ^ Kaufman, Rachel (August 8, 2012). "Could Space Mirrors Stop Global Warming?". Live Science. Retrieved 2019-11-08.
- ^ Sánchez, Joan-Pau; McInnes, Colin R. (2015-08-26). "Optimal Sunshade Configurations for Space-Based Geoengineering near the Sun-Earth L1 Point". PLOS ONE. 10 (8): e0136648. Bibcode:2015PLoSO..1036648S. doi:10.1371/journal.pone.0136648. ISSN 1932-6203. PMC 4550401. PMID 26309047.
- ^ Crutzen, P. J. (2006). "Albedo Enhancement by Stratospheric Sulfur Injections: A Contribution to Resolve a Policy Dilemma?". Climatic Change. 77 (3–4): 211–220. Bibcode:2006ClCh...77..211C. doi:10.1007/s10584-006-9101-y.
- ^ "Chapter 2 : Land–Climate interactions: Special Report on Climate Change and Land". Retrieved 2023-10-20.
- ^ Wang, Zhuosen; Schaaf, Crystal B.; Sun, Qingsong; Kim, JiHyun; Erb, Angela M.; Gao, Feng; Román, Miguel O.; Yang, Yun; Petroy, Shelley; Taylor, Jeffrey R.; Masek, Jeffrey G.; Morisette, Jeffrey T.; Zhang, Xiaoyang; Papuga, Shirley A. (2017-07-01). "Monitoring land surface albedo and vegetation dynamics using high spatial and temporal resolution synthetic time series from Landsat and the MODIS BRDF/NBAR/albedo product". International Journal of Applied Earth Observation and Geoinformation. 59: 104–117. doi:10.1016/j.jag.2017.03.008. ISSN 1569-8432. PMC 7641169. PMID 33154713.
- ^ a b Wolovick, Michael J.; Moore, John C. (20 September 2018). "Stopping the flood: could we use targeted geoengineering to mitigate sea level rise?". The Cryosphere. 12 (9): 2955–2967. doi:10.5194/tc-12-2955-2018.
- ^ Wolovick, Michael; Moore, John; Keefer, Bowie (27 March 2023). "Feasibility of ice sheet conservation using seabed anchored curtains". PNAS Nexus. 2 (3): pgad053. doi:10.1093/pnasnexus/pgad053. PMC 10062297. PMID 37007716.
- ^ Wolovick, Michael; Moore, John; Keefer, Bowie (27 March 2023). "The potential for stabilizing Amundsen Sea glaciers via underwater curtains". PNAS Nexus. 2 (4): pgad103. doi:10.1093/pnasnexus/pgad103. PMC 10118300. PMID 37091546.
- ^ "The radical intervention that might save the "doomsday" glacier". MIT Technology Review. Retrieved 2022-01-14.
- ^ a b c d e f g Voosen, Paul (16 December 2022). "Ocean geoengineering scheme aces its first field test". www.science.org. Retrieved 2022-12-19.
- ^ Buis, Alan (November 7, 2019). "Examining the Viability of Planting Trees to Help Mitigate Climate Change". Climate Change: Vital Signs of the Planet. Retrieved 2023-04-13.
- ^ Marshall, Michael (26 May 2020). "Planting trees doesn't always help with climate change". BBC. Retrieved 2023-04-13.
- ^ 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
- ^ Schenuit, Felix; Colvin, Rebecca; Fridahl, Mathias; McMullin, Barry; Reisinger, Andy; Sanchez, Daniel L.; Smith, Stephen M.; Torvanger, Asbjørn; Wreford, Anita; Geden, Oliver (2021-03-04). "Carbon Dioxide Removal Policy in the Making: Assessing Developments in 9 OECD Cases". Frontiers in Climate. 3: 638805. doi:10.3389/fclim.2021.638805. hdl:1885/270309. ISSN 2624-9553.
- ^ 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.
- ^ Ho, David T. (2023-04-04). "Carbon dioxide removal is not a current climate solution — we need to change the narrative". Nature. 616 (7955): 9. Bibcode:2023Natur.616....9H. doi:10.1038/d41586-023-00953-x. ISSN 0028-0836. PMID 37016122. S2CID 257915220.
- ^ a b c M. Pathak, R. Slade, P.R. Shukla, J. Skea, R. Pichs-Madruga, D. Ürge-Vorsatz,2022: Technical Summary. In: Climate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [P.R. Shukla, J. Skea, R. Slade, A. Al Khourdajie, R. van Diemen, D. McCollum, M. Pathak, S. Some, P. Vyas, R. Fradera, M. Belkacemi, A. Hasija, G. Lisboa, S. Luz, J. Malley, (eds.)]. Cambridge University Press, Cambridge, UK and New York, NY, USA. doi: 10.1017/9781009157926.002.
- ^ Lebling, Katie; Northrop, Eliza; McCormick, Colin; Bridgwater, Liz (November 15, 2022), "Toward Responsible and Informed Ocean-Based Carbon Dioxide Removal: Research and Governance Priorities" (PDF), World Resources Institute: 11, doi:10.46830/wrirpt.21.00090, S2CID 253561039
- ^ Schenuit, Felix; Gidden, Matthew J.; Boettcher, Miranda; Brutschin, Elina; Fyson, Claire; Gasser, Thomas; Geden, Oliver; Lamb, William F.; Mace, M. J.; Minx, Jan; Riahi, Keywan (2023-10-03). "Secure robust carbon dioxide removal policy through credible certification". Communications Earth & Environment. 4 (1): 349. Bibcode:2023ComEE...4..349S. doi:10.1038/s43247-023-01014-x. ISSN 2662-4435.
- ^ a b Trisos, Christopher H.; Geden, Oliver; Seneviratne, Sonia I.; Sugiyama, Masahiro; van Aalst, Maarten; Bala, Govindasamy; Mach, Katharine J.; Ginzburg, Veronika; de Coninck, Heleen; Patt, Anthony. "Cross-Working Group Box SRM: Solar Radiation Modification" (PDF). Cambridge, United Kingdom and New York, NY, USA: Cambridge University Press. pp. 221–222. doi:10.1017/9781009325844.004.
In Climate Change 2022: Impacts, Adaptation and Vulnerability [H.-O. Pörtner, D.C. Roberts, M. Tignor, E.S. Poloczanska, K. Mintenbeck, A. Alegría, M. Craig, S. Langsdorf, S. Löschke,V. Möller, A. Okem, B. Rama (eds.)].
- ^ Intergovernmental Panel on Climate Change (IPCC) (2023-07-06). Climate Change 2021 – The Physical Science Basis: Working Group I Contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (1 ed.). Cambridge University Press. doi:10.1017/9781009157896.006. ISBN 978-1-009-15789-6.
- ^ Environment, U. N. (2023-02-28). "One Atmosphere: An Independent Expert Review on Solar Radiation Modification Research and Deployment". UNEP - UN Environment Programme. Retrieved 2024-03-09.
- ^ World Meteorological Organization (WMO) (2022). Scientific Assessment of Ozone Depletion: 2022. Geneva: WMO. ISBN 978-9914-733-99-0.
- ^ Wang, Tong; Wu, Yi; Shi, Lan; Hu, Xinhua; Chen, Min; Wu, Limin (2021). "A structural polymer for highly efficient all-day passive radiative cooling". Nature Communications. 12 (365): 365. doi:10.1038/s41467-020-20646-7. PMC 7809060. PMID 33446648.
One possibly alternative approach is passive radiative cooling—a sky-facing surface on the Earth spontaneously cools by radiating heat to the ultracold outer space through the atmosphere's longwave infrared (LWIR) transparency window (λ ~ 8–13 μm).
- ^ Munday, Jeremy (2019). "Tackling Climate Change through Radiative Cooling". Joule. 3 (9): 2057–2060. doi:10.1016/j.joule.2019.07.010. S2CID 201590290.
A reduction in solar absorption is usually proposed through the injection of reflective aerosols into the atmosphere; however, serious concerns have been raised regarding side effects of these forms of geoengineering and our ability to undo any of the climatic changes we create.
- ^ a b Chen, Meijie; Pang, Dan; Chen, Xingyu; Yan, Hongjie; Yang, Yuan (2022). "Passive daytime radiative cooling: Fundamentals, material designs, and applications". EcoMat. 4. doi:10.1002/eom2.12153. S2CID 240331557.
Passive daytime radiative cooling (PDRC) dissipates terrestrial heat to the extremely cold outer space without using any energy input or producing pollution. It has the potential to simultaneously alleviate the two major problems of energy crisis and global warming.
- ^ Wang, Tong; Wu, Yi; Shi, Lan; Hu, Xinhua; Chen, Min; Wu, Limin (2021). "A structural polymer for highly efficient all-day passive radiative cooling". Nature Communications. 12 (365): 365. doi:10.1038/s41467-020-20646-7. PMC 7809060. PMID 33446648.
Accordingly, designing and fabricating efficient PDRC with sufficiently high solar reflectance (𝜌¯solar) (λ ~ 0.3–2.5 μm) to minimize solar heat gain and simultaneously strong LWIR thermal emittance (ε¯LWIR) to maximize radiative heat loss is highly desirable. When the incoming radiative heat from the Sun is balanced by the outgoing radiative heat emission, the temperature of the Earth can reach its steady state.
- ^ Zevenhovena, Ron; Fält, Martin (June 2018). "Radiative cooling through the atmospheric window: A third, less intrusive geoengineering approach". Energy. 152: 27. Bibcode:2018Ene...152...27Z. doi:10.1016/j.energy.2018.03.084. S2CID 116318678 – via Elsevier Science Direct.
An alternative, third geoengineering approach would be enhanced cooling by thermal radiation from the Earth's surface into space." [...] "With 100 W/m2 as a demonstrated passive cooling effect, a surface coverage of 0.3% would then be needed, or 1% of Earth's land mass surface. If half of it would be installed in urban, built areas which cover roughly 3% of the Earth's land mass, a 17% coverage would be needed there, with the remainder being installed in rural areas.
- ^ Heo, Se-Yeon; Ju Lee, Gil; Song, Young Min (June 2022). "Heat-shedding with photonic structures: radiative cooling and its potential". Journal of Materials Chemistry C. 10 (27): 9915–9937. doi:10.1039/D2TC00318J. S2CID 249695930 – via Royal Society of Chemistry.
- ^ Aili, Ablimit; Yin, Xiaobo; Yang, Ronggui (October 2021). "Global Radiative Sky Cooling Potential Adjusted for Population Density and Cooling Demand". Atmosphere. 12 (11): 1379. Bibcode:2021Atmos..12.1379A. doi:10.3390/atmos12111379.
- ^ Chen, Jianheng; Lu, Lin; Gong, Quan (June 2021). "A new study on passive radiative sky cooling resource maps of China". Energy Conversion and Management. 237: 114132. Bibcode:2021ECM...23714132C. doi:10.1016/j.enconman.2021.114132. S2CID 234839652 – via Elsevier Science Direct.
Passive radiative cooling utilizes atmospheric transparency window (8–13 μm) to discharge heat into outer space and inhibits solar absorption.
- ^ a b Bijarniya, Jay Prakash; Sarkar, Jahar; Maiti, Pralay (November 2020). "Review on passive daytime radiative cooling: Fundamentals, recent researches, challenges and opportunities". Renewable and Sustainable Energy Reviews. 133: 110263. doi:10.1016/j.rser.2020.110263. S2CID 224874019 – via Elsevier Science Direct.
- ^ Benmoussa, Youssef; Ezziani, Maria; Djire, All-Fousseni; Amine, Zaynab; Khaldoun, Asmae; Limami, Houssame (September 2022). "Simulation of an energy-efficient cool roof with cellulose-based daytime radiative cooling material". Materials Today: Proceedings. 72: 3632–3637. doi:10.1016/j.matpr.2022.08.411. S2CID 252136357 – via Elsevier Science Direct.
- ^ Khan, Ansar; Carlosena, Laura; Feng, Jie; Khorat, Samiran; Khatun, Rupali; Doan, Quang-Van; Santamouris, Mattheos (January 2022). "Optically Modulated Passive Broadband Daytime Radiative Cooling Materials Can Cool Cities in Summer and Heat Cities in Winter". Sustainability. 14 – via MDPI.
- ^ Anand, Jyothis; Sailor, David J.; Baniassadi, Amir (February 2021). "The relative role of solar reflectance and thermal emittance for passive daytime radiative cooling technologies applied to rooftops". Sustainable Cities and Society. 65: 102612. doi:10.1016/j.scs.2020.102612. S2CID 229476136 – via Elsevier Science Direct.
- ^ Liang, Jun; Wu, Jiawei; Guo, Jun; Li, Huagen; Zhou, Xianjun; Liang, Sheng; Qiu, Cheng-Wei; Tao, Guangming (September 2022). "Radiative cooling for passive thermal management towards sustainable carbon neutrality". National Science Review. 10 (1): nwac208. doi:10.1093/nsr/nwac208. PMC 9843130. PMID 36684522.
- ^ Munday, Jeremy (2019). "Tackling Climate Change through Radiative Cooling". Joule. 3 (9): 2057–2060. doi:10.1016/j.joule.2019.07.010. S2CID 201590290.
By covering the Earth with a small fraction of thermally emitting materials, the heat flow away from the Earth can be increased, and the net radiative flux can be reduced to zero (or even made negative), thus stabilizing (or cooling) the Earth.
- ^ Yin, Xiaobo; Yang, Ronggui; Tan, Gang; Fan, Shanhui (November 2020). "Terrestrial radiative cooling: Using the cold universe as a renewable and sustainable energy source". Science. 370 (6518): 786–791. Bibcode:2020Sci...370..786Y. doi:10.1126/science.abb0971. PMID 33184205. S2CID 226308213.
...terrestrial radiative cooling has emerged as a promising solution for mitigating urban heat islands and for potentially fighting against global warming if it can be implemented at a large scale.
- ^ Richter, Hannah (12 July 2024). "To avoid sea level rise, some researchers want to build barriers around the world's most vulnerable glaciers". Science magazine.
- ^ Wingenter, Oliver W.; Haase, Karl B.; Strutton, Peter; Friederich, Gernot; Meinardi, Simone; Blake, Donald R.; Rowland, F. Sherwood (8 June 2004). "Changing concentrations of CO, CH4, C5H8, CH3Br, CH3I, and dimethyl sulfide during the Southern Ocean Iron Enrichment Experiments". Proceedings of the National Academy of Sciences of the United States of America. 101 (23): 8537–8541. Bibcode:2004PNAS..101.8537W. doi:10.1073/pnas.0402744101. ISSN 0027-8424. PMC 423229. PMID 15173582.
- ^ Wingenter, Oliver W.; Elliot, Scott M.; Blake, Donald R. (November 2007). "New Directions: Enhancing the natural sulfur cycle to slow global warming". Atmospheric Environment. 41 (34): 7373–5. Bibcode:2007AtmEn..41.7373W. doi:10.1016/j.atmosenv.2007.07.021. S2CID 43279436. Archived from the original on 13 August 2020. Retrieved 18 September 2020.
- ^ Joughin, I. (16 May 2014). "Marine Ice Sheet Collapse Potentially Under Way for the Thwaites Glacier Basin, West Antarctica". Science. 344 (6185): 735–738. Bibcode:2014Sci...344..735J. doi:10.1126/science.1249055. PMID 24821948. S2CID 206554077.
- ^ a b c Temple, James (14 January 2022). "The radical intervention that might save the "doomsday" glacier". MIT Technology Review. Retrieved 19 July 2023.
- ^ a b c Wolovick, Michael J.; Moore, John C. (20 September 2018). "Stopping the flood: could we use targeted geoengineering to mitigate sea level rise?". The Cryosphere. 12 (9): 2955–2967. Bibcode:2018TCry...12.2955W. doi:10.5194/tc-12-2955-2018. S2CID 52969664.
- ^ Moon, Twila A. (25 April 2018). "Geoengineering might speed glacier melt". Nature. 556 (7702): 436. Bibcode:2018Natur.556R.436M. doi:10.1038/d41586-018-04897-5. PMID 29695853.
- ^ a b Wolovick, Michael; Moore, John; Keefer, Bowie (27 March 2023). "Feasibility of ice sheet conservation using seabed anchored curtains". PNAS Nexus. 2 (3): pgad053. doi:10.1093/pnasnexus/pgad053. PMC 10062297. PMID 37007716.
- ^ a b Wolovick, Michael; Moore, John; Keefer, Bowie (27 March 2023). "The potential for stabilizing Amundsen Sea glaciers via underwater curtains". PNAS Nexus. 2 (4): pgad103. doi:10.1093/pnasnexus/pgad103. PMC 10118300. PMID 37091546.
- ^ a b Adam, David (1 September 2008). "Extreme and risky action the only way to tackle global warming, say scientists". The Guardian. Archived from the original on 2019-08-06. Retrieved 2009-05-23.
- ^ "Geoengineering". International Risk Governance Council. 2009. Archived from the original on 2009-12-03. Retrieved 2009-10-07.
- ^ Kahan, Dan M.; Jenkins-Smith, Hank; Tarantola, Tor; Silva, Carol L.; Braman, Donald (2015-03-01). "Geoengineering and Climate Change Polarization Testing a Two-Channel Model of Science Communication". The Annals of the American Academy of Political and Social Science. 658 (1): 192–222. doi:10.1177/0002716214559002. ISSN 0002-7162. S2CID 149147565.
- ^ Wibeck, Victoria; Hansson, Anders; Anshelm, Jonas (2015-05-01). "Questioning the technological fix to climate change – Lay sense-making of geoengineering in Sweden". Energy Research & Social Science. 7: 23–30. doi:10.1016/j.erss.2015.03.001.
- ^ Merk, Christine; Pönitzsch, Gert; Kniebes, Carola; Rehdanz, Katrin; Schmidt, Ulrich (2015-02-10). "Exploring public perceptions of stratospheric sulfate injection". Climatic Change. 130 (2): 299–312. Bibcode:2015ClCh..130..299M. doi:10.1007/s10584-014-1317-7. ISSN 0165-0009. S2CID 154196324.
- ^ Reynolds, Jesse (2015-08-01). "A critical examination of the climate engineering moral hazard and risk compensation concern". The Anthropocene Review. 2 (2): 174–191. doi:10.1177/2053019614554304. ISSN 2053-0196. S2CID 59407485.
- ^ Morrow, David R. (2014-12-28). "Ethical aspects of the mitigation obstruction argument against climate engineering research". Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and Engineering Sciences. 372 (2031): 20140062. Bibcode:2014RSPTA.37240062M. doi:10.1098/rsta.2014.0062. ISSN 1364-503X. PMID 25404676.
- ^ Urpelainen, Johannes (2012-02-10). "Geoengineering and global warming: a strategic perspective". International Environmental Agreements: Politics, Law and Economics. 12 (4): 375–389. doi:10.1007/s10784-012-9167-0. ISSN 1567-9764. S2CID 154422202.
- ^ Moreno-Cruz, Juan B. (2015-08-01). "Mitigation and the geoengineering threat". Resource and Energy Economics. 41: 248–263. doi:10.1016/j.reseneeco.2015.06.001. hdl:1853/44254.
- ^ Clingerman, F.; O'Brien, K. (2014). "Playing God: why religion belongs in the climate engineering debate". Bulletin of the Atomic Scientists. 70 (3): 27–37. Bibcode:2014BuAtS..70c..27C. doi:10.1177/0096340214531181. S2CID 143742343.
- ^ Wright, Malcolm J.; Teagle, Damon A. H.; Feetham, Pamela M. (February 2014). "A quantitative evaluation of the public response to climate engineering". Nature Climate Change. 4 (2): 106–110. Bibcode:2014NatCC...4..106W. doi:10.1038/nclimate2087. ISSN 1758-6798. Archived from the original on 2020-07-28. Retrieved 2020-05-22.
- ^ Parr, Doug (1 September 2008). "Geo-engineering is no solution to climate change". Guardian Newspaper. London. Archived from the original on 2018-08-20. Retrieved 2009-05-23.
- ^ Bullis, Kevin. "U.S. Congress Considers Geoengineering". MIT Technology Review. Archived from the original on 26 January 2013. Retrieved 26 December 2012.
- ^ "Climate Intervention Reports » Climate Change at the National Academies of Sciences, Engineering, and Medicine". nas-sites.org. Archived from the original on 2016-07-29. Retrieved 2015-11-02.
- ^ "Stop emitting CO2 or geoengineering could be our only hope" (Press release). The Royal Society. 28 August 2009. Archived from the original on 24 June 2011. Retrieved 14 June 2011.
- ^ "Geo-engineering research" (PDF). Postnote. Parliamentary Office of Science and Technology. March 2009. Retrieved 2022-09-11.
- ^ a b "Geo-engineering – Giving us the time to act?". I Mech E. Archived from the original on 2011-07-22. Retrieved 2011-03-12.
- ^ a b Working group (2009). Geoengineering the Climate: Science, Governance and Uncertainty (PDF) (Report). London: The Royal Society. p. 1. ISBN 978-0-85403-773-5. RS1636. Archived (PDF) from the original on 2014-03-12. Retrieved 2011-12-01.
- ^ a b Lenton, T.M.; Vaughan, N.E. (2009). "The radiative forcing potential of different climate geoengineering options". Atmospheric Chemistry and Physics. 9 (15): 5539–5561. Bibcode:2009ACP.....9.5539L. doi:10.5194/acp-9-5539-2009. Archived from the original on 2019-12-14. Retrieved 2009-09-04.
- ^ "Climate Intervention Is Not a Replacement for Reducing Carbon Emissions; Proposed Intervention Techniques Not Ready for Wide-Scale Deployment". NEWS from the national academies (Press release). Feb 10, 2015. Archived from the original on 2015-11-17. Retrieved 2015-11-24.
- ^ National Research Council (2017). Climate Intervention: Reflecting Sunlight to Cool Earth. The National Academies Press. doi:10.17226/18988. ISBN 978-0-309-31482-4. Ebook: ISBN 978-0-309-31485-5.
- ^ National Research Council (2015). Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration. doi:10.17226/18805. ISBN 978-0-309-30529-7. Archived from the original on 2018-08-21. Retrieved 2018-08-20.
- ^ National Research Council (2015). Climate Intervention: Reflecting Sunlight to Cool Earth. National Academies Press. ISBN 978-0-309-31482-4. Archived from the original on 2019-12-14. Retrieved 2018-08-20.
- ^ National Research Council (2015). Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration. National Academies Press. ISBN 978-0-309-30529-7. Archived from the original on 2018-08-21. Retrieved 2018-08-20.
- ^ Hanley, Steve (2023-07-03). "US & EU Quietly Begin To Discuss Geoengineering". CleanTechnica. Retrieved 2023-07-06.
- ^ "Marine Cloud Brightening Program studies clouds, aerosols and pathways to reduce climate risks". College of the Environment. Retrieved 2024-04-08.