Solar geoengineering

From Wikipedia, the free encyclopedia
Jump to navigation Jump to search

refer to caption and image description
Proposed stratospheric aerosol injection research using a tethered balloon to inject aerosols into the stratosphere.

Solar geoengineering, or solar radiation modification (SRM) is a type of climate engineering in which sunlight (solar radiation) would be reflected back to space to limit or reverse human-caused climate change. It is not a substitute for reducing greenhouse gas emissions, but would act as a temporary measure to limit warming while emissions of greenhouse gases are reduced and carbon dioxide is removed. The most studied methods of SRM are stratospheric aerosol injection, marine cloud brightening,[1] and passive daytime radiative cooling.[2][3][4]

Solar geoengineering appears able to prevent some or much of climate change temperature increases.[5][6] Climate models consistently indicate that it is capable of returning global, regional, and local temperatures and precipitation closer to pre-industrial levels. Solar geoengineering's principal advantages are the speed with which it could be deployed and become active and the reversibility of its direct climatic effects,[7] although the latter varies depending on method, with passive radiative cooling described as more reversible than stratospheric aerosol injection.[8][9]

Proposed methods of solar geoengineering may be atmospheric, terrestrial, or space-based. Stratospheric aerosol injection appears technically feasible and inexpensive in terms of direct financial costs, though still out of reach for individuals, small states, or other non-state rogue actors; it would instead be the exclusive domain of large national economies or coalitions including at least one such economy.[7] Passive daytime radiative cooling is a terrestrial method that uses sky-facing solar reflective and heat emissive surfaces that require zero energy consumption; it has experienced a surge of research and development since the 2010s.[2][3][4] Space-based propositions are only theoretical, being too expensive and infeasible to implement.[10]

Solar geoengineering would not directly reduce carbon dioxide concentrations in the atmosphere, and thus does not address ocean acidification or air pollution caused by high levels of atmospheric CO2.[6] Solar geoengineering's excessive and/or poorly distributed use, or sudden and sustained termination, could pose serious environmental risks. Other negative impacts are possible and more research is required to thoroughly address such impacts.[11] Governing solar geoengineering is challenging for multiple reasons, including that few countries would likely be capable of doing it alone.[11]

Overview[edit]

Means of operation[edit]

Averaged over the year and location, the Earth's atmosphere receives 340 W/m2 of solar irradiance from the sun.[12] Due to elevated atmospheric greenhouse gas concentrations, the net difference between the amount of sunlight absorbed by the Earth and the amount of energy radiated back to space has risen from 1.7 W/m2 in 1980, to 3.1 W/m2 in 2019.[13] This imbalance - called radiative forcing - means that the Earth absorbs more energy than it lets off, causing global temperatures to rise.[14] The goal of solar geoengineering would be to reduce radiative forcing by increasing Earth's albedo (reflectivity). An increase by about 1% of the incident solar radiation would be sufficient to eliminate current radiative forcing and thereby global warming, while a 2% albedo increase would roughly halve the effect of doubling the atmospheric carbon dioxide concentration.[15] However, because warming from greenhouse gases and cooling from solar geoengineering operate differently across latitudes and seasons, this counter-effect would be imperfect.

Potential roles[edit]

Solar geoengineering is almost universally intended to complement, not replace, greenhouse gas emissions reduction, carbon dioxide removal (those two together are called "mitigation"), and adaptation efforts. For example, the Royal Society stated in its landmark 2009 report: "Geoengineering methods are not a substitute for climate change mitigation, and should only be considered as part of a wider package of options for addressing climate change."[16] Such statements are very common in solar geoengineering publications.

Potential complementary responses to climate change: greenhouse gas emissions abatement, carbon dioxide removal, solar geoengineering, and adaptation. Originally called the "napkin diagram" and drawn by John Shepherd.[17]

Solar geoengineering's speed of effect gives it two potential roles in managing risks from climate change. First, if mitigation and adaptation continue to be insufficient, and/or if climate change impacts are severe due to greater-than-expected climate sensitivity, tipping points, or vulnerability, then solar geoengineering could reduce these unexpectedly severe impacts. In this way, the knowledge to implement solar geoengineering as a backup plan would serve as a sort of risk diversification or insurance. Second, solar geoengineering could be implemented along with aggressive mitigation and adaptation in order "buy time" by slowing the rate of climate change and/or to eliminate the worst climate impacts until net negative emissions reduce atmospheric greenhouse gas concentrations. (See diagram.)

Solar geoengineering has been suggested as a means of stabilizing regional climates - such as limiting heat waves,[18] but control over the geographical boundaries of the effect appears very difficult.

History[edit]

The 1965 landmark report "Restoring the Quality of Our Environment" by U.S. President Lyndon B. Johnson's Science Advisory Committee warned of the harmful effects of carbon dioxide emissions from fossil fuel and mentioned "deliberately bringing about countervailing climatic changes," including "raising the albedo, or reflectivity, of the Earth."[19] As early as 1974, Russian climatologist Mikhail Budyko suggested that if global warming ever became a serious threat, it could be countered with airplane flights in the stratosphere, burning sulfur to make aerosols that would reflect sunlight away.[20] Along with carbon dioxide removal, solar geoengineering was discussed jointly as "geoengineering" in a 1992 climate change report from the US National Academies.[21] The topic was essentially taboo in the climate science and policy communities until Nobel Laureate Paul Crutzen published an influential scholarly paper in 2006.[22] Major reports by the Royal Society (2009)[23] and the US National Academies (2015, 2021)[24][25] followed. Total research funding worldwide remains modest, less than 10 million US dollars annually.[26] Almost all research into solar geoengineering has to date consisted of computer modeling or laboratory tests,[27] and there are calls for more research funding as the science is poorly understood.[28] [29] Only a few outdoor tests and experiments have proceeded. Major academic institutions, including Harvard University, have begun research into solar geoengineering.[30] The Degrees Initiative is a registered charity in the UK which was established in 2010 to build capacity in developing countries to evaluate solar geoengineering.[31] The 2021 US National Academy of Sciences, Engineering, and Medicine report recommended an initial investment into solar geoengineering research of $100–$200 million over five years.[29] In May 2022, the Climate Overshoot Commission was launched to recommend a comprehensive strategy to reduce climate risk which includes sunlight reflection methods in its policy portfolio, and will issue a final report prior to the 2023 UN Climate Change Conference. [32]

Evidence of effectiveness and impacts[edit]

Modeling evidence of the effect of greenhouse gases and solar geoengineering on average annual temperature (left column) and precipitation (right column).[33] The first row (a) is moderately high continued greenhouse gas emissions (RCP4.5) at the end of the century. The second row (b) is the same emissions scenario and time, with solar geoengineering to reduce global warming to 1.5 degrees C. The third row (c) is the same emissions scenario but in the near future, when global warming would be 1.5 degrees C, with no solar geoengineering. The similarity between the second and third rows suggests that solar geoengineering could reduce climate change reasonably well.

Climate models consistently indicate that a moderate magnitude of solar geoengineering would bring important aspects of the climate - for example, average and extreme temperature, water availability, cyclone intensity - closer to their preindustrial values at a subregional resolution.[5] (See figure.)

The Intergovernmental Panel on Climate Change (IPCC) concluded in its Sixth Assessment Report:[34]: 69 

.... SRM could offset some of the effects of increasing GHGs on global and regional climate, including the carbon and water cycles. However, there would be substantial residual or overcompensating climate change at the regional scales and seasonal time scales, and large uncertainties associated with aerosol–cloud–radiation interactions persist. The cooling caused by SRM would increase the global land and ocean CO2 sinks, but this would not stop CO2 from increasing in the atmosphere or affect the resulting ocean acidification under continued anthropogenic emissions. It is likely that abrupt water cycle changes will occur if SRM techniques are implemented rapidly. A sudden and sustained termination of SRM in a high CO2 emissions scenario would cause rapid climate change. However, a gradual phase-out of SRM combined with emission reduction and CDR would avoid these termination effects.

The 2021 US National Academy of Sciences, Engineering, and Medicine report states: "The available research indicates that SG could reduce surface temperatures and potentially ameliorate some risks posed by climate change (e.g., to avoid crossing critical climate 'tipping points'; to reduce harmful impacts of weather extremes)."[25]

Solar geoengineering would imperfectly compensate for anthropogenic climate changes. Greenhouse gases warm throughout the globe and year, whereas solar geoengineering reflects light more effectively at low latitudes and in the hemispheric summer (due to the sunlight's angle of incidence) and only during daytime. Deployment regimes could compensate for this heterogeneity by changing and optimizing injection rates by latitude and season.[35][36]

In general, greenhouse gases warm the entire planet and are expected to change precipitation patterns heterogeneously, both spatially and temporally, with an overall increase in precipitation. Models indicate that solar geoengineering would compensate both of these changes but would do more effectively for temperature than for precipitation. Therefore, using solar geoengineering to fully return global mean temperature to a preindustrial level would overcorrect for precipitation changes. This has led to claims that it would dry the planet or even cause drought, but this would depend on the intensity (i.e. radiative forcing) of solar geoengineering. Furthermore, soil moisture is more important for plants than average annual precipitation. Because solar geoengineering would reduce evaporation, it more precisely compensates for changes to soil moisture than for average annual precipitation.[37] Likewise, the intensity of tropical monsoons is increased by climate change and decreased by solar geoengineering.[38] A net reduction in tropical monsoon intensity might manifest at moderate use of solar geoengineering, although to some degree the effect of this on humans and ecosystems would be mitigated by greater net precipitation outside of the monsoon system. This has led to claims that solar geoengineering "would disrupt the Asian and African summer monsoons," but the impact would depend on the particular implementation regime.

People are concerned about climate change largely because of its impacts on people and ecosystems. In the case of the former, agriculture is particularly important. A net increase in agricultural productivity from elevated atmospheric carbon dioxide concentrations and solar geoengineering has also been predicted by some studies due to the combination of more diffuse light and carbon dioxide's fertilization effect.[39] Other studies suggest that solar geoengineering would have little net effect on agriculture.[40] Understanding of solar geoengineering's effects on ecosystems remains at an early stage. Its reduction of climate change would generally help maintain ecosystems, although the resulting more diffuse incoming sunlight would favor undergrowth relative to canopy growth.

Advantages[edit]

The target of net zero greenhouse gas emissions can be achieved through a combination of emission cuts and carbon dioxide removal, after which global warming stops,[41] but the temperature will only go back down if we remove more carbon dioxide than we emit. Solar geoengineering on the other hand could cool the planet within months after deployment,[42] thus can act to reduce climate risk while we cut emissions and scale up carbon dioxide removal. Stratospheric aerosol injection is expected to have low direct financial costs of implementation,[7][43] relative to the expected costs of both unabated climate change and aggressive mitigation. Finally, the direct climatic effects of solar geoengineering are reversible within short timescales.[42]

Limitations and risks[edit]

As well as the imperfect cancellation of the climatic effect of greenhouse gases, described above, there are other significant problems with solar geoengineering.

Incomplete solution to elevated carbon dioxide concentrations[edit]

Change in sea surface pH caused by anthropogenic CO2 between the 1700s and the 1990s. This ocean acidification will still be a major problem unless atmospheric CO2 is reduced.

Solar geoengineering does not remove greenhouse gases from the atmosphere and thus does not reduce other effects from these gases, such as ocean acidification.[44] While not an argument against solar geoengineering per se, this is an argument against reliance on it to the exclusion of emissions reduction.

Uncertainty[edit]

Most of the information on solar geoengineering comes from climate models and volcanic eruptions, which are both imperfect analogues of stratospheric aerosol injection. The climate models used in impact assessments are the same that scientists use to predict the impacts of anthropogenic climate change. Some uncertainties in these climate models (such as aerosol microphysics, stratospheric dynamics, and sub-grid scale mixing) are particularly relevant to solar geoengineering and are a target for future research.[45] Volcanoes are an imperfect analogue as they release the material in the stratosphere in a single pulse, as opposed to sustained injection.[46] Modelling is uncertain as little practical research has been done.[11]

Maintenance and termination shock[edit]

Solar geoengineering effects would be temporary, and thus long-term climate restoration would rely on long-term deployment until sufficient carbon dioxide is removed.[47][48] If solar geoengineering masked significant warming, stopped abruptly, and was not resumed within a year or so, the climate would rapidly warm.[49] Global temperatures would rapidly rise towards levels which would have existed without the use of solar geoengineering. The rapid rise in temperature might lead to more severe consequences than a gradual rise of the same magnitude. However, some scholars have argued that this termination shock appears reasonably easy to prevent because it would be in states' interest to resume any terminated deployment regime; and because infrastructure and knowledge could be made redundant and resilient, allowing states to act on this interest and gradually phase out unwanted solar geoengineering.[50][51]

Some claim that solar geoengineering "would basically be impossible to stop."[52][53] This is true only of a long-term deployment strategy. A short-term, temporary strategy would limit implementation to decades.[54] In any case, solar geoengineering could be phased out.[citation needed]

Disagreement and control[edit]

Although climate models of solar geoengineering rely on some optimal or consistent implementation, leaders of countries and other actors may disagree as to whether, how, and to what degree solar geoengineering be used. This could result in suboptimal deployments and exacerbate international tensions.[55]

Some observers claim that solar geoengineering is likely to be militarized or weaponized. However, weaponization is disputed because solar geoengineering would be imprecise.[56] Regardless, the U.N. Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques, which would prohibit weaponizing solar geoengineering, came into force in 1978.[57]

Unwanted or premature use[edit]

There is a risk that countries may start using solar geoengineering without proper precaution or research. Solar geoengineering, at least by stratospheric aerosol injection, appears to have low direct implementation costs relative to its potential impact. This creates a different problem structure.[58][59] Whereas the provision of emissions reduction and carbon dioxide removal present collective action problems (because ensuring a lower atmospheric carbon dioxide concentration is a public good), a single country or a handful of countries could implement solar geoengineering. Many countries have the financial and technical resources to undertake solar geoengineering.[11]

David Victor suggests that solar geoengineering is within the reach of a lone "Greenfinger," a wealthy individual who takes it upon him or herself to be the "self-appointed protector of the planet".[60][61] Others disagree and argue that states will insist on maintaining control of solar geoengineering.[62]

Distribution of effects[edit]

Both climate change and solar geoengineering would affect various groups of people differently. Some observers describe solar geoengineering as necessarily creating "winners and losers." However, models indicate that solar geoengineering at a moderate intensity would return important climatic values of almost all regions of the planet closer to preindustrial conditions.[citation needed] That is, if all people prefer preindustrial conditions, such a moderate use could be a Pareto improvement.

Developing countries are particularly important, as they are more vulnerable to climate change. All else equal, they therefore have the most to gain from a judicious use of solar geoengineering. Observers sometimes claim that solar geoengineering poses greater risks to developing countries. There is no evidence that the unwanted environmental impacts of solar geoengineering would be significantly greater in developing countries, although potential disruptions to tropical monsoons are a concern. But in one sense, this claim of greater risk is true for the same reason that they are more vulnerable to greenhouse gas-induced climate change: developing countries have weaker infrastructure and institutions, and their economies rely to a greater degree on agriculture. They are thus more vulnerable to all climate changes, whether from greenhouse gases or solar geoengineering.

Lessened mitigation[edit]

The existence of solar geoengineering may reduce the political and social impetus for mitigation.[63] This has generally been called a potential "moral hazard," although risk compensation may be a more accurate term. This concern causes many environmental groups and campaigners to be reluctant to advocate or discuss solar geoengineering.[64] However, several public opinion surveys and focus groups have found evidence of either assertions of a desire to increase emission cuts in the face of solar geoengineering, or of no effect.[65][66][67][68][69][70][71] Likewise, some modelling work suggests that the threat of solar geoengineering may in fact increase the likelihood of emissions reduction.[72][73][74][75]

Effect on sky and clouds[edit]

Managing solar radiation using aerosols or cloud cover would involve changing the ratio between direct and indirect solar radiation. This would affect plant life[76] and solar energy.[77] Visible light, useful for photosynthesis, is reduced proportionally more than is the infrared portion of the solar spectrum due to the mechanism of Mie scattering.[78] As a result, deployment of atmospheric solar geoengineering would reduce by at least 2-5% the growth rates of phytoplankton, trees, and crops [79] between now and the end of the century.[80] Uniformly reduced net shortwave radiation would hurt solar photovoltaics by the same >2-5% because of the bandgap of silicon photovoltaics.[81]

Proposed forms[edit]

Atmospheric[edit]

Stratospheric aerosol injection[edit]

Injecting reflective aerosols into the stratosphere is the proposed solar geoengineering method that has received the most sustained attention. The Intergovernmental Panel on Climate Change concluded that Stratospheric aerosol injection "is the most-researched SRM method, with high agreement that it could limit warming to below 1.5°C."[82] This technique would mimic a cooling phenomenon that occurs naturally by the eruption of volcanoes.[83] Sulfates are the most commonly proposed aerosol, since there is a natural analogue with (and evidence from) volcanic eruptions. Alternative materials such as using photophoretic particles, titanium dioxide, and diamond have been proposed.[84][85][86][87][88] Delivery by custom aircraft appears most feasible, with artillery and balloons sometimes discussed.[89][90][91] The annual cost of delivering a sufficient amount of sulfur to counteract expected greenhouse warming is estimated at $5 to 10 billion US dollars.[92] This technique could give much more than 3.7 W/m2 of globally averaged negative forcing,[93] which is sufficient to entirely offset the warming caused by a doubling of carbon dioxide.

Marine cloud brightening[edit]

Various cloud reflectivity methods have been suggested, such as that proposed by John Latham and Stephen Salter, which works by spraying seawater in the atmosphere to increase the reflectivity of clouds.[94] The extra condensation nuclei created by the spray would change the size distribution of the drops in existing clouds to make them whiter.[95] The sprayers would use fleets of unmanned rotor ships known as Flettner vessels to spray mist created from seawater into the air to thicken clouds and thus reflect more radiation from the Earth.[96] The whitening effect is created by using very small cloud condensation nuclei, which whiten the clouds due to the Twomey effect.

This technique can give more than 3.7 W/m2 of globally averaged negative forcing,[93] which is sufficient to reverse the warming effect of a doubling of atmospheric carbon dioxide concentration.

Cirrus cloud thinning[edit]

Natural cirrus clouds are believed to have a net warming effect. These could be dispersed by the injection of various materials. This method is strictly not solar geoengineering, as it increases outgoing longwave radiation instead of decreasing incoming shortwave radiation. However, because it shares some of the physical and especially governance characteristics as the other solar geoengineering methods, it is often included.[97]

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.[98][99] Such fertilization, especially in the Southern Ocean, would enhance dimethyl sulfide production and consequently cloud reflectivity. This could potentially be used as regional solar geoengineering, 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.

Terrestrial[edit]

Passive daytime radiative cooling[edit]

The widespread application of passive daytime radiative cooling (PDRC) surfaces deployed on the Earth's surface has been proposed as a method of reducing global temperature increases caused by climate change.[6][100] PDRC surfaces are designed to maximize the efficiency of solar reflectance and thermal emissivity by reflecting heat back into outer space through the atmosphere's longwave infrared (LWIR) transparency window (8–13 µm) during the daytime.[101] One advantage of PDRC surfaces is that they work while requiring zero energy consumption or pollution.[6][102] Jeremy Munday summarized the global implementation:

Currently the Earth is absorbing ∼1 W/m2 more than it is emitting, which leads to an overall warming of the climate. 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 (...) If only 1%–2% of the Earth’s surface were instead made to radiate [heat] at this rate rather than its current average value, the total heat fluxes into and away from the entire Earth would be balanced and warming would cease.[6]

PDRC surfaces can take different forms and involve different components, including photonic structures, polymers, dielectrics, dielectric-polymer composites,[103] and biodegradable emitters,[104] that have been designed for daytime cooling.[105][106] For PDRC heat emitters to be functional on a global scale, they must be designed "to ensure that the emission is through the atmospheric transparency window and out to space, rather than just to the atmosphere, which would allow for local but not global cooling."[6] Climatic variables such as humidity, cloud cover, and wind can alter PDRC effectiveness.[107][108][109] Using passive radiative cooling has been argued to be more stable, adaptable, and reversible than stratospheric aerosol injection.[8][9]

Cool roof[edit]

The albedo of several types of roofs

Painting roof materials in white or pale colors to reflect solar radiation, known as 'cool roof' technology, is encouraged by legislation in some areas (notably California).[110] This technique is limited in its ultimate effectiveness by the constrained surface area available for treatment. This technique can give between 0.01 and 0.19 W/m2 of globally averaged negative forcing, depending on whether cities or all settlements are so treated.[93] This is small relative to the 3.7 W/m2 of positive forcing from a doubling of atmospheric carbon dioxide. Moreover, while in small cases it can be achieved at little or no cost by simply selecting different materials, it can be costly if implemented on a larger scale. A 2009 Royal Society report states that, "the overall cost of a 'white roof method' covering an area of 1% of the land surface (about 1012 m2) would be about $300 billion/yr, making this one of the least effective and most expensive methods considered."[111] However, it can reduce the need for air conditioning, which emits carbon dioxide and contributes to global warming.

Ocean and ice changes[edit]

Oceanic foams have also been suggested, using microscopic bubbles suspended in the upper layers of the photic zone. A less costly proposal is to simply lengthen and brighten existing ship wakes.[112]

Arctic sea ice formation could be increased by pumping deep cooler water to the surface.[113] Sea ice (and terrestrial) ice can be thickened by increasing albedo with silica spheres.[114] Glaciers flowing into the sea may be stabilized by blocking the flow of warm water to the glacier.[115] Salt water could be pumped out of the ocean and snowed onto the West Antarctic ice sheet.[116][117]

Vegetation[edit]

Reforestation in tropical areas has a cooling effect. Changes to grassland have been proposed to increase albedo.[118] This technique can give 0.64 W/m2 of globally averaged negative forcing,[93] which is insufficient to offset the 3.7 W/m2 of positive forcing from a doubling of carbon dioxide, but could make a minor contribution. Selecting or genetically modifying commercial crops with high albedo has been suggested.[119] This has the advantage of being relatively simple to implement, with farmers simply switching from one variety to another. Temperate areas may experience a 1 °C cooling as a result of this technique.[120] This technique is an example of bio-geoengineering. This technique can give 0.44 W/m2 of globally averaged negative forcing,[93] which is insufficient to offset the 3.7 W/m2 of positive forcing from a doubling of carbon dioxide, but could make a minor contribution.

Space-based[edit]

The basic function of a space lens to mitigate global warming. In reality, a 1000 kilometre diameter lens is enough, much smaller than what is shown in the simplified image. In addition, as a Fresnel lens it would only be a few millimeters thick.

Space-based solar geoengineering projects are seen by most commentators and scientists as being very expensive and technically difficult, with the Royal Society suggesting that "the costs of setting in place such a space-based armada for the relatively short period that solar geoengineering may be considered applicable (decades rather than centuries) would likely make it uncompetitive with other solar geoengineering approaches."[10]

Several authors have proposed dispersing light before it reaches the Earth by putting a very large diffraction grating (thin wire mesh) or lens in space, perhaps at the L1 point between the Earth and the Sun. Using a Fresnel lens in this manner was proposed in 1989 by J. T. Early,[121] and a diffraction grating in 1997 by Edward Teller, Lowell Wood, and Roderick Hyde.[122] In 2004, physicist and science fiction author Gregory Benford calculated that a concave rotating Fresnel lens 1000 kilometers across, yet only a few millimeters thick, floating in space at the L1 point, would reduce the solar energy reaching the Earth by approximately 0.5% to 1%. He estimated that this would cost around US$10 billion up front, and another $10 billion in supportive cost during its lifespan.[123] One issue would be the need to counteract the effects of the solar wind moving such megastructures out of position. Mirrors orbiting around the Earth are another option.[94][124]

Governance[edit]

Solar geoengineering poses several governance challenges because of its high leverage, low apparent direct costs, and technical feasibility as well as issues of power and jurisdiction.[125] Solar geoengineering does not require widespread participation, although that may be desirable. Because international law is generally consensual, this creates a challenge of participation that is the inverse of that of mitigation to reduce climate change, where widespread participation is required. Discussions are broadly on who will have control over the deployment of solar geoengineering and under what governance regime the deployment can be monitored and supervised. A governance framework for solar geoengineering must be sustainable enough to contain a multilateral commitment over a long period of time and yet be flexible as information is acquired, the techniques evolve, and interests change through time.

Legal and regulatory systems may face a significant challenge in effectively regulating solar geoengineering in a manner that allows for an acceptable result for society. Some researchers have suggested that building a global agreement on solar geoengineering deployment will be very difficult, and instead power blocs are likely to emerge.[126] There are, however, significant incentives for states to cooperate in choosing a specific solar geoengineering policy, which make unilateral deployment a rather unlikely event.[127]

In 2021, the National Academies of Sciences, Engineering, and Medicine released their consensus study report Recommendations for Solar Geoengineering Research and Research Governance, concluding:[128]

[A] strategic investment in research is needed to enhance policymakers' understanding of climate response options. The United States should develop a transdisciplinary research program, in collaboration with other nations, to advance understanding of solar geoengineering's technical feasibility and effectiveness, possible impacts on society and the environment, and social dimensions such as public perceptions, political and economic dynamics, and ethical and equity considerations. The program should operate under robust research governance that includes such elements as a research code of conduct, a public registry for research, permitting systems for outdoor experiments, guidance on intellectual property, and inclusive public and stakeholder engagement processes.[128]

Public attitudes and politics[edit]

There have been a handful of studies into attitudes to and opinions of solar geoengineering. These generally find low levels of awareness, uneasiness with the implementation of solar geoengineering, cautious support of research, and a preference for greenhouse gas emissions reduction.[129][130] As is often the case with public opinions regarding emerging issues, the responses are highly sensitive to the questions' particular wording and context. Although most public opinion studies have polled residents of developed countries, those that have examined residents of developing countries—which tend to be more vulnerable to climate change impacts—find slightly greater levels of support there.[131][132][133]

There are many controversies surrounding this topic and hence, solar geoengineering has become a very political issue. No countries have an explicit government position on solar geoengineering.

Support for solar geoengineering research comes almost entirely from those who are concerned about climate change. Some observers claim that political conservatives, opponents of action to reduce climate change, and fossil fuel firms are major advocates of solar geoengineering research.[134] However, only a handful of conservatives and opponents of climate action have expressed support, and there is no evidence that fossil fuel firms are involved in solar geoengineering research.[135] Instead, these claims often conflate solar geoengineering and carbon dioxide removal—where fossil fuel firms are involved—under the broader term "geoengineering."

Some environmental groups have endorsed solar geoengineering research[136][137][138] while others are opposed.[139]

As noted, the interests and roles of developing countries are particularly important.[140] The Solar Radiation Management Governance Initiative works toward "expanding an informed international conversation about SRM research and its governance, and building the capacity of developing countries to evaluate this controversial technology."[141] Among other activities, it provides grants to researchers in the Global South.

In 2021, researchers at Harvard were forced to put plans for a solar geoengineering test on hold after Indigenous Sámi people objected to the test taking place in their homeland.[142][143] Although the test would not have involved any immediate atmospheric experiments, members of the Saami Council spoke out against the lack of consultation and solar geoengineering more broadly. Speaking at a panel organized by the Center for International Environmental Law and other groups, Saami Council Vice President Åsa Larsson Blind said, "This goes against our worldview that we as humans should live and adapt to nature."

See also[edit]

References[edit]

  1. ^ National Academies of Sciences, Engineering (25 March 2021). Reflecting Sunlight: Recommendations for Solar Geoengineering Research and Research Governance. doi:10.17226/25762. ISBN 978-0-309-67605-2. S2CID 234327299.
  2. ^ a b Chen, Meijie; Pang, Dan; Chen, Xingyu; Yan, Hongjie; Yang, Yuan (October 2021). "Passive daytime radiative cooling: Fundamentals, material designs, and applications". EcoMat. 4 – via Wiley. 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.
  3. ^ a b 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. The research and development of PDRCs have grown tremendously in the last decade.
  4. ^ a b Zhang, Qian; Wang, Shauihao; Wang, Xueyang; Jiang, Yi; Li, Jinlei; Xu, Weilin; Zhu, Bin; Zhu, Jia (February 2022). "Recent Progress in Daytime Radiative Cooling: Advanced Material Designs and Applications". Small Methods. 6 (4) – via Wiley Online Library.
  5. ^ a b Irvine, Peter; Emanuel, Kerry; He, Jie; Horowitz, Larry W.; Vecchi, Gabriel; Keith, David (April 2019). "Halving warming with idealized solar geoengineering moderates key climate hazards". Nature Climate Change. 9 (4): 295–299. Bibcode:2019NatCC...9..295I. doi:10.1038/s41558-019-0398-8. hdl:1721.1/126780. ISSN 1758-6798. S2CID 84833420. Archived from the original on 12 March 2019. Retrieved 13 March 2019.
  6. ^ a b c d e f Munday, Jeremy (2019). "Tackling Climate Change through Radiative Cooling". Joule. 3 (9) – via ScienceDirect.
  7. ^ a b c Smith, Wake (October 2020). "The cost of stratospheric aerosol injection through 2100". Environmental Research Letters. 15 (11): 114004. Bibcode:2020ERL....15k4004S. doi:10.1088/1748-9326/aba7e7. ISSN 1748-9326. S2CID 225534263.
  8. ^ a b Munday, Jeremy (2019). "Tackling Climate Change through Radiative Cooling". Joule. 3 (9): 2057 – via ScienceDirect. 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.
  9. ^ a b 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: 2 – via nature.com. The basic idea behind SRM is to seed reflective particles into the Earth’s stratosphere to reduce solar absorption, which might cause potentially dangerous threats to the Earth’s basic climate operations. 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).
  10. ^ a b "The Royal Society" (PDF). royalsociety.org. Archived (PDF) from the original on 21 July 2015. Retrieved 18 November 2015.
  11. ^ a b c d Gernot Wagner (2021). Geoengineering: the Gamble.
  12. ^ Coddington, O.; Lean, J. L.; Pilewskie, P.; Snow, M.; Lindholm, D. (22 August 2016). "A Solar Irradiance Climate Data Record". Bulletin of the American Meteorological Society. 97 (7): 1265–1282. Bibcode:2016BAMS...97.1265C. doi:10.1175/bams-d-14-00265.1.
  13. ^ US Department of Commerce, NOAA. "NOAA/ESRL Global Monitoring Laboratory - THE NOAA ANNUAL GREENHOUSE GAS INDEX (AGGI)". www.esrl.noaa.gov. Archived from the original on 22 September 2013. Retrieved 28 October 2020.
  14. ^ NASA. "The Causes of Climate Change". Climate Change: Vital Signs of the Planet. Archived from the original on 8 May 2019. Retrieved 8 May 2019.
  15. ^ "The Royal Society" (PDF). royalsociety.org. Archived (PDF) from the original on 21 July 2015. Retrieved 20 October 2015.
  16. ^ "The Royal Society" (PDF). royalsociety.org. Archived (PDF) from the original on 21 July 2015. Retrieved 11 September 2015.
  17. ^ Reynolds, Jesse L. (27 September 2019). "Solar geoengineering to reduce climate change: a review of governance proposals". Proceedings of the Royal Society A: Mathematical, Physical and Engineering Sciences. 475 (2229): 20190255. Bibcode:2019RSPSA.47590255R. doi:10.1098/rspa.2019.0255. PMC 6784395. PMID 31611719.
  18. ^ Bernstein, D. N.; Neelin, J. D.; Li, Q. B.; Chen, D. (2013). "Could aerosol emissions be used for regional heat wave mitigation?". Atmospheric Chemistry and Physics. 13 (13): 6373. Bibcode:2013ACP....13.6373B. doi:10.5194/acp-13-6373-2013.
  19. ^ "Geoengineering: A Short History". Foreign Policy. 2013. Archived from the original on 22 May 2019. Retrieved 7 June 2021.
  20. ^ Rasch, Philip J; Tilmes, Simone; Turco, Richard P; Robock, Alan; Oman, Luke; Chen, Chih-Chieh (Jack); Stenchikov, Georgiy L; Garcia, Rolando R (13 November 2008). "An overview of geoengineering of climate using stratospheric sulphate aerosols". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 366 (1882): 4007–4037. Bibcode:2008RSPTA.366.4007R. doi:10.1098/rsta.2008.0131. PMID 18757276. S2CID 9869660. Archived from the original on 2 November 2020. Retrieved 28 October 2020.
  21. ^ Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base. Washington, D.C.: National Academies Press. 1 January 1992. doi:10.17226/1605. ISBN 978-0-309-04386-1. Archived from the original on 21 November 2021. Retrieved 6 June 2021.
  22. ^ Crutzen, Paul J. (25 July 2006). "Albedo Enhancement by Stratospheric Sulfur Injections: A Contribution to Resolve a Policy Dilemma?". Climatic Change. 77 (3): 211–220. Bibcode:2006ClCh...77..211C. doi:10.1007/s10584-006-9101-y. ISSN 1573-1480. S2CID 154081541.
  23. ^ Geoengineering the climate : science, governance and uncertainty. Royal Society. London: Royal Society. 2009. ISBN 9780854037735. OCLC 436232805. Archived from the original on 7 June 2020. Retrieved 6 June 2021.{{cite book}}: CS1 maint: others (link)
  24. ^ Council, National Research (10 February 2015). Climate Intervention: Reflecting Sunlight to Cool Earth. doi:10.17226/18988. ISBN 978-0-309-31482-4. Archived from the original on 14 December 2019. Retrieved 6 June 2021.
  25. ^ a b National Academies of Sciences, Engineering (25 March 2021). 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 17 April 2021. Retrieved 14 April 2021.
  26. ^ "Funding for Solar Geoengineering from 2008 to 2018". geoengineering.environment.harvard.edu. Archived from the original on 6 June 2021. Retrieved 6 June 2021.
  27. ^ Loria, Kevin (20 July 2017). "A last-resort 'planet-hacking' plan could make Earth habitable for longer – but scientists warn it could have dramatic consequences". Business Insider. Archived from the original on 12 January 2019. Retrieved 7 August 2017.
  28. ^ "Give research into solar geoengineering a chance". Nature. 593 (7858): 167. 12 May 2021. Bibcode:2021Natur.593..167.. doi:10.1038/d41586-021-01243-0. PMID 33981056. Archived from the original on 13 May 2021. Retrieved 7 June 2021.
  29. ^ a b Reflecting Sunlight: Recommendations for Solar Geoengineering Research and Research Governance. National Academies of Sciences, Engineering, and Medicine. 25 March 2021. p. 17. doi:10.17226/25762. ISBN 978-0-309-67605-2. S2CID 234327299. Archived from the original on 19 April 2021. Retrieved 7 June 2021.
  30. ^ "Geoengineering". geoengineering.environment.harvard.edu. Archived from the original on 6 June 2021. Retrieved 7 June 2021.
  31. ^ Info. "About us". The DEGREES Initiative. Retrieved 11 July 2022.
  32. ^ "MISSION". Overshoot Commission. Retrieved 11 July 2022.
  33. ^ MacMartin, Douglas G.; Ricke, Katharine L.; Keith, David W. (13 May 2018). "Solar geoengineering as part of an overall strategy for meeting the 1.5°C Paris target". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 376 (2119): 20160454. Bibcode:2018RSPTA.37660454M. doi:10.1098/rsta.2016.0454. ISSN 1364-503X. PMC 5897825. PMID 29610384.
  34. ^ Arias, Paola A.; Bellouin, Nicolas; Coppola, Erika; Jones, Richard G.; et al. (2021). "Technical Summary" (PDF). Climate Change 2021: The Physical Science Basis.
  35. ^ Tilmes, Simone; Richter, Jadwiga H.; Kravitz, Ben; MacMartin, Douglas G.; Mills, Michael J.; Simpson, Isla R.; Glanville, Anne S.; Fasullo, John T.; Phillips, Adam S.; Lamarque, Jean-Francois; Tribbia, Joseph (November 2018). "CESM1(WACCM) Stratospheric Aerosol Geoengineering Large Ensemble Project". Bulletin of the American Meteorological Society. 99 (11): 2361–2371. Bibcode:2018BAMS...99.2361T. doi:10.1175/BAMS-D-17-0267.1. ISSN 0003-0007. S2CID 125977140. Archived from the original on 11 June 2021. Retrieved 11 June 2021.
  36. ^ Visioni, Daniele; MacMartin, Douglas G.; Kravitz, Ben; Richter, Jadwiga H.; Tilmes, Simone; Mills, Michael J. (28 June 2020). "Seasonally Modulated Stratospheric Aerosol Geoengineering Alters the Climate Outcomes". Geophysical Research Letters. 47 (12): e88337. Bibcode:2020GeoRL..4788337V. doi:10.1029/2020GL088337. ISSN 0094-8276.
  37. ^ Cheng, Wei; MacMartin, Douglas G.; Dagon, Katherine; Kravitz, Ben; Tilmes, Simone; Richter, Jadwiga H.; Mills, Michael J.; Simpson, Isla R. (16 December 2019). "Soil Moisture and Other Hydrological Changes in a Stratospheric Aerosol Geoengineering Large Ensemble". Journal of Geophysical Research: Atmospheres. 124 (23): 12773–12793. Bibcode:2019JGRD..12412773C. doi:10.1029/2018JD030237. ISSN 2169-897X. S2CID 203137017.
  38. ^ Bhowmick, Mansi; Mishra, Saroj Kanta; Kravitz, Ben; Sahany, Sandeep; Salunke, Popat (December 2021). "Response of the Indian summer monsoon to global warming, solar geoengineering and its termination". Scientific Reports. 11 (1): 9791. Bibcode:2021NatSR..11.9791B. doi:10.1038/s41598-021-89249-6. ISSN 2045-2322. PMC 8105343. PMID 33963266.
  39. ^ Pongratz, J.; Lobell, D. B.; Cao, L.; Caldeira, K. (2012). "Crop yields in a geoengineered climate". Nature Climate Change. 2 (2): 101. Bibcode:2012NatCC...2..101P. doi:10.1038/nclimate1373. S2CID 86725229. Archived from the original on 21 November 2021. Retrieved 30 November 2019.
  40. ^ Proctor, Jonathan; Hsiang, Solomon; Burney, Jennifer; Burke, Marshall; Schlenker, Wolfram (August 2018). "Estimating global agricultural effects of geoengineering using volcanic eruptions". Nature. 560 (7719): 480–483. Bibcode:2018Natur.560..480P. doi:10.1038/s41586-018-0417-3. ISSN 0028-0836. PMID 30089909. S2CID 51939867. Archived from the original on 12 June 2021. Retrieved 11 June 2021.
  41. ^ "Explainer: Will global warming 'stop' as soon as net-zero emissions are reached?". Carbon Brief. 29 April 2021. Retrieved 11 July 2022.
  42. ^ a b Council, National Research; Impacts, Committee on Geoengineering Climate: Technical Evaluation Discussion of; Division On Earth And Life Studies, National Research Council (U.S.); Ocean Studies Board, National Research Council (U.S.); Climate, Board on Atmospheric Sciences (10 February 2015). Climate Intervention: Reflecting Sunlight to Cool Earth | The National Academies Press. www.nap.edu. ISBN 9780309314824. Archived from the original on 14 December 2019. Retrieved 11 September 2015.
  43. ^ Moriyama, Ryo; Sugiyama, Masahiro; Kurosawa, Atsushi; Masuda, Kooiti; Tsuzuki, Kazuhiro; Ishimoto, Yuki (8 September 2016). "The cost of stratospheric climate engineering revisited". Mitigation and Adaptation Strategies for Global Change. 22 (8): 1207–1228. doi:10.1007/s11027-016-9723-y. ISSN 1381-2386. S2CID 157441259.
  44. ^ Wingenter, Oliver W.; Haase, Karl B.; Zeigler, Max; Blake, Donald R.; Rowland, F. Sherwood; Sive, Barkley C.; Paulino, Ana; Thyrhaug, Runar; Larsen, Aud; Schulz, Kai; Meyerhöfer, Michael (2007). "Unexpected consequences of increasing CO 2 and ocean acidity on marine production of DMS and CH 2 ClI: Potential climate impacts: IMPACT OF OCEAN ACIDITY ON DMS AND CH 2 CLI". Geophysical Research Letters. 34 (5). doi:10.1029/2006GL028139.
  45. ^ Kravitz, Ben; MacMartin, Douglas G. (January 2020). "Uncertainty and the basis for confidence in solar geoengineering research". Nature Reviews Earth & Environment. 1 (1): 64–75. Bibcode:2020NRvEE...1...64K. doi:10.1038/s43017-019-0004-7. ISSN 2662-138X. S2CID 210169322. Archived from the original on 10 May 2021. Retrieved 21 March 2021.
  46. ^ Duan, Lei; Cao, Long; Bala, Govindasamy; Caldeira, Ken (2019). "Climate Response to Pulse Versus Sustained Stratospheric Aerosol Forcing". Geophysical Research Letters. 46 (15): 8976–8984. Bibcode:2019GeoRL..46.8976D. doi:10.1029/2019GL083701. ISSN 1944-8007. S2CID 201283770. Archived from the original on 15 November 2019. Retrieved 21 March 2021.
  47. ^ Moreno-Cruz, Juan B.; Ricke, Katharine L.; Keith, David W. (2011). "A simple model to account for regional inequalities in the effectiveness of solar radiation management". Climatic Change. 110 (3–4): 649. doi:10.1007/s10584-011-0103-z. S2CID 18903547.
  48. ^ Keith, David W.; MacMartin, Douglas G. (2015). "A temporary, moderate and responsive scenario for solar geoengineering" (PDF). Nature Climate Change. 5 (3): 201. Bibcode:2015NatCC...5..201K. doi:10.1038/nclimate2493. Archived (PDF) from the original on 22 July 2018. Retrieved 25 November 2018.
  49. ^ Ross, A.; Damon Matthews, H. (2009). "Climate engineering and the risk of rapid climate change". Environmental Research Letters. 4 (4): 045103. Bibcode:2009ERL.....4d5103R. doi:10.1088/1748-9326/4/4/045103.
  50. ^ Parker, Andy; Irvine, Peter J. (March 2018). "The Risk of Termination Shock From Solar Geoengineering". Earth's Future. 6 (3): 456–467. Bibcode:2018EaFut...6..456P. doi:10.1002/2017EF000735. S2CID 48359567.
  51. ^ Rabitz, Florian (16 April 2019). "Governing the termination problem in solar radiation management". Environmental Politics. 28 (3): 502–522. doi:10.1080/09644016.2018.1519879. ISSN 0964-4016. S2CID 158738431. Archived from the original on 11 June 2021. Retrieved 11 June 2021.
  52. ^ Klein, Naomi (2014). This changes everything : capitalism vs. the climate (First Simon & Schuster hardcover ed.). New York. ISBN 978-1-4516-9738-4. OCLC 881875853. Archived from the original on 21 November 2021. Retrieved 11 June 2021.
  53. ^ Bengtsson, L. (2006) 'Geo-engineering to confine climate change: is it at all feasible?' Climatic Change 77: 229–234
  54. ^ Keith, David W.; MacMartin, Douglas G. (2015). "A temporary, moderate and responsive scenario for solar geoengineering" (PDF). Nature Climate Change. 5 (3): 201–206. Bibcode:2015NatCC...5..201K. doi:10.1038/nclimate2493. Archived (PDF) from the original on 22 July 2018. Retrieved 25 November 2018.
  55. ^ Shaw, Jonathan (8 October 2020). "Controlling the Global Thermostat". Harvard Magazine. Archived from the original on 1 November 2020. Retrieved 3 November 2020.
  56. ^ Horton, Joshua and David Keith (29 April 2021). "Can Solar Geoengineering Be Used as a Weapon?". Council on Foreign Relations. Archived from the original on 11 June 2021. Retrieved 11 June 2021.
  57. ^ Robock, A.; Marquardt, A.; Kravitz, B.; Stenchikov, G. (2009). "Benefits, Risks, and costs of stratospheric geoengineering". Geophysical Research Letters. 36 (19): D19703. Bibcode:2009GeoRL..3619703R. doi:10.1029/2009GL039209. hdl:10754/552099. S2CID 34488313.
  58. ^ Barrett, Scott (1 January 2008). "The Incredible Economics of Geoengineering". Environmental and Resource Economics. 39 (1): 45–54. doi:10.1007/s10640-007-9174-8. ISSN 0924-6460. S2CID 153889188.
  59. ^ Weitzman, Martin L. (14 July 2015). "A Voting Architecture for the Governance of Free-Driver Externalities, with Application to Geoengineering". The Scandinavian Journal of Economics. 117 (4): 1049–1068. doi:10.1111/sjoe.12120. S2CID 2991157. Archived from the original on 9 June 2020. Retrieved 25 November 2018.
  60. ^ Victor, David G. (2008). "On the regulation of geoengineering". Oxford Review of Economic Policy. 24 (2): 322–336. CiteSeerX 10.1.1.536.5401. doi:10.1093/oxrep/grn018.
  61. ^ "The Geoengineering Option". Foreign Affairs (March/April 2009). March 2009. Archived from the original on 19 November 2015. Retrieved 18 November 2015.
  62. ^ Parson, Edward A. (April 2014). "Climate Engineering in Global Climate Governance: Implications for Participation and Linkage". Transnational Environmental Law. 3 (1): 89–110. doi:10.1017/S2047102513000496. ISSN 2047-1025. S2CID 56018220. Archived from the original on 21 November 2021. Retrieved 11 June 2021.
  63. ^ 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 6 August 2019. Retrieved 23 May 2009.
  64. ^ "Geo-Engineering – a Moral Hazard". celsias.com. 14 November 2007. Archived from the original on 14 January 2011. Retrieved 9 September 2010.
  65. ^ 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 12 March 2014. Retrieved 1 December 2011.
  66. ^ Ipsos MORI (August 2010). Experiment Earth? Report on a Public Dialogue on Geoengineering (PDF) (Report). Archived (PDF) from the original on 15 February 2019. Retrieved 6 June 2021.
  67. ^ Mercer, A M; Keith, D W; Sharp, J D (1 December 2011). "Public understanding of solar radiation management – IOPscience" (PDF). Environmental Research Letters. 6 (4): 044006. Bibcode:2011ERL.....6d4006M. doi:10.1088/1748-9326/6/4/044006. Archived (PDF) from the original on 31 March 2019. Retrieved 6 June 2021.
  68. ^ Kahan, Dan M.; Jenkins-Smith, Hank; Tarantola, Tor; Silva, Carol L.; Braman, Donald (1 March 2015). "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.
  69. ^ Views about geoengineering: Key findings from public discussion groups (PDF) (Report). Integrated Assessment of Geoengineering Proposals. 31 July 2014. Archived (PDF) from the original on 23 December 2016. Retrieved 6 June 2021.
  70. ^ Wibeck, Victoria; Hansson, Anders; Anshelm, Jonas (1 May 2015). "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.
  71. ^ Merk, Christine; Pönitzsch, Gert; Kniebes, Carola; Rehdanz, Katrin; Schmidt, Ulrich (10 February 2015). "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.
  72. ^ Millard-Ball, A. (2011). "The Tuvalu Syndrome". Climatic Change. 110 (3–4): 1047–1066. doi:10.1007/s10584-011-0102-0. S2CID 153990911.
  73. ^ Urpelainen, Johannes (10 February 2012). "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.
  74. ^ Goeschl, Timo; Heyen, Daniel; Moreno-Cruz, Juan (20 March 2013). "The Intergenerational Transfer of Solar Radiation Management Capabilities and Atmospheric Carbon Stocks" (PDF). Environmental and Resource Economics. 56 (1): 85–104. doi:10.1007/s10640-013-9647-x. hdl:10419/127358. ISSN 0924-6460. S2CID 52213135. Archived (PDF) from the original on 4 December 2020. Retrieved 6 June 2021.
  75. ^ Moreno-Cruz, Juan B. (1 August 2015). "Mitigation and the geoengineering threat". Resource and Energy Economics. 41: 248–263. doi:10.1016/j.reseneeco.2015.06.001. hdl:1853/44254.
  76. ^ Gu, L.; et al. (1999). "Responses of Net Ecosystem Exchanges of Carbon Dioxide to Changes in Cloudiness: Results from Two North American Deciduous Forests". Journal of Geophysical Research. 104 (D24): 31421–31, 31434. Bibcode:1999JGR...10431421G. doi:10.1029/1999jd901068. hdl:2429/34802. S2CID 128613057.; Gu, L.; et al. (2002). "Advantages of Diffuse Radiation for Terrestrial Ecosystem Productivity". Journal of Geophysical Research. 107 (D6): ACL 2-1-ACL 2-23. Bibcode:2002JGRD..107.4050G. doi:10.1029/2001jd001242. hdl:2429/34834.; Gu, L.; et al. (March 2003). "Response of a Deciduous Forest to the Mount Pinatubo Eruption: Enhanced Photosynthesis" (PDF). Science. 299 (5615): 2035–38. Bibcode:2003Sci...299.2035G. doi:10.1126/science.1078366. PMID 12663919. S2CID 6086118. Archived (PDF) from the original on 21 November 2018. Retrieved 2 June 2018.
  77. ^ Govindasamy, Balan; Caldeira, Ken (2000). "Geoengineering Earth's Radiation Balance to Mitigate CO2-Induced Climate Change". Geophysical Research Letters. 27 (14): 2141–44. Bibcode:2000GeoRL..27.2141G. doi:10.1029/1999gl006086. For the response of solar power systems, see MacCracken, Michael C. (2006). "Geoengineering: Worthy of Cautious Evaluation?". Climatic Change. 77 (3–4): 235–43. Bibcode:2006ClCh...77..235M. doi:10.1007/s10584-006-9130-6.
  78. ^ Erlick, Carynelisa; Frederick, John E (1998). "Effects of aerosols on the wavelength dependence of atmospheric transmission in the ultraviolet and visible 2. Continental and urban aerosols in clear skies". J. Geophys. Res. 103 (D18): 23275–23285. Bibcode:1998JGR...10323275E. doi:10.1029/98JD02119.
  79. ^ Walker, David Alan (1989). "Automated measurement of leaf photosynthetic O2 evolution as a function of photon flux density". Philosophical Transactions of the Royal Society B. 323 (1216): 313–326. Bibcode:1989RSPTB.323..313W. doi:10.1098/rstb.1989.0013. Archived from the original on 21 November 2021. Retrieved 20 October 2020.
  80. ^ IPCC, Data Distribution Center. "Representative Concentration Pathways (RCPs)". Intergovernmental Panel on Climate Change. Archived from the original on 21 October 2020. Retrieved 20 October 2020.
  81. ^ Murphy, Daniel (2009). "Effect of Stratospheric Aerosols on Direct Sunlight and Implications for Concentrating Solar Power". Environ. Sci. Technol. 43 (8): 2783–2786. Bibcode:2009EnST...43.2784M. doi:10.1021/es802206b. PMID 19475950. Archived from the original on 21 November 2021. Retrieved 20 October 2020.
  82. ^ Global warming of 1.5°C. Intergovernmental Panel on Climate Change. [Geneva, Switzerland]. 2018. ISBN 9789291691517. OCLC 1056192590.{{cite book}}: CS1 maint: others (link)
  83. ^ Self, Stephen; Zhao, Jing-Xia; Holasek, Rick E.; Torres, Ronnie C. & McTaggart, Joey (1999). "The Atmospheric Impact of the 1991 Mount Pinatubo Eruption". Archived from the original on 2 August 2014. Retrieved 25 July 2014.
  84. ^ Mason, Betsy (16 September 2020). "Why solar geoengineering should be part of the climate crisis solution". Knowable Magazine. doi:10.1146/knowable-091620-2.
  85. ^ Keith, David W. (November 2000). "Geoengineering the climate : History and Prospect". Annual Review of Energy and the Environment. 25 (1): 245–284. doi:10.1146/annurev.energy.25.1.245. Archived from the original on 29 June 2021. Retrieved 29 June 2021.
  86. ^ Keith, D. W. (2010). "Photophoretic levitation of engineered aerosols for geoengineering". Proceedings of the National Academy of Sciences. 107 (38): 16428–16431. Bibcode:2010PNAS..10716428K. doi:10.1073/pnas.1009519107. PMC 2944714. PMID 20823254.
  87. ^ Weisenstein, D. K.; Keith, D. W. (2015). "Solar geoengineering using solid aerosol in the stratosphere". Atmospheric Chemistry and Physics Discussions. 15 (8): 11799–11851. Bibcode:2015ACPD...1511799W. doi:10.5194/acpd-15-11799-2015.
  88. ^ Ferraro, A. J., A. J. Charlton-Perez, E. J. Highwood (2015). "Stratospheric dynamics and midlatitude jets under geoengineering with space mirrors and sulfate and titania aerosols". Journal of Geophysical Research: Atmospheres. 120 (2): 414–429. Bibcode:2015JGRD..120..414F. doi:10.1002/2014JD022734. hdl:10871/16214. S2CID 33804616.
  89. ^ 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.
  90. ^ Davidson, P.; Burgoyne, C.; Hunt, H.; Causier, M. (2012). "Lifting options for stratospheric aerosol geoengineering: Advantages of tethered balloon systems". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 370 (1974): 4263–300. Bibcode:2012RSPTA.370.4263D. doi:10.1098/rsta.2011.0639. PMID 22869799.
  91. ^ "Can a Million Tons of Sulfur Dioxide Combat Climate Change?". Wired.com. 23 June 2008. Archived from the original on 4 February 2014. Retrieved 11 March 2017.
  92. ^ Smith, Wake (21 October 2020). "The cost of stratospheric aerosol injection through 2100". Environmental Research Letters. 15 (11): 114004. Bibcode:2020ERL....15k4004S. doi:10.1088/1748-9326/aba7e7. ISSN 1748-9326.
  93. ^ a b c d e Lenton, T. M., Vaughan, N. E. (2009). "The radiative forcing potential of different climate geoengineering options" (PDF). Atmos. Chem. Phys. Discuss. 9 (1): 2559–2608. doi:10.5194/acpd-9-2559-2009.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  94. ^ a b "Programmes | Five Ways To Save The World". BBC News. 20 February 2007. Archived from the original on 10 June 2009. Retrieved 16 October 2013.
  95. ^ Panel on Policy Implications of Greenhouse Warming, National Academy of Sciences, National Academy of Engineering, Institute of Medicine (1992). Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base. The National Academies Press. ISBN 978-0-585-03095-1. Archived from the original on 7 June 2011. Retrieved 31 December 2008. {{cite book}}: |author= has generic name (help)CS1 maint: multiple names: authors list (link)
  96. ^ Latham, J. (1990). "Control of global warming" (PDF). Nature. 347 (6291): 339–340. Bibcode:1990Natur.347..339L. doi:10.1038/347339b0. S2CID 4340327. Archived from the original (PDF) on 16 July 2011.
  97. ^ Committee on Developing a Research Agenda and Research Governance Approaches for Climate Intervention Strategies that Reflect Sunlight to Cool Earth; Board on Atmospheric Sciences and Climate; Committee on Science, Technology, and Law; Division on Earth and Life Studies; Policy and Global Affairs; National Academies of Sciences, Engineering, and Medicine (28 May 2021). Reflecting Sunlight: Recommendations for Solar Geoengineering Research and Research Governance. Washington, D.C.: National Academies Press. doi:10.17226/25762. ISBN 978-0-309-67605-2. S2CID 234327299. {{cite book}}: |last5= has generic name (help)CS1 maint: multiple names: authors list (link)
  98. ^ 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.
  99. ^ 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.
  100. ^ Chen, Meijie; Pang, Dan; Chen, Xingyu; Yan, Hongjie; Yang, Yuan (October 2021). "Passive daytime radiative cooling: Fundamentals, material designs, and applications". EcoMat. 4 – via Wiley.
  101. ^ 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) – via nature.com.
  102. ^ Chen, Meijie; Pang, Dan; Chen, Xingyu; Yan, Hongjie; Yang, Yuan (October 2021). "Passive daytime radiative cooling: Fundamentals, material designs, and applications". EcoMat. 4 – via Wiley.
  103. ^ Chen, Meijie; Pang, Dan; Chen, Xingyu; Yan, Hongjie; Yang, Yuan (October 2021). "Passive daytime radiative cooling: Fundamentals, material designs, and applications". EcoMat. 4 – via Wiley.
  104. ^ Park, Chanil; Park, Choyeon; Nie, Xiao; Lee, Jaeho; Kim, Yong Seok; Yoo, Youngjae (2022). "Fully Organic and Flexible Biodegradable Emitter for Global Energy-Free Cooling Applications". ACS Sustainable Chem. Eng. 10 (21) – via ACS Publications.
  105. ^ 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) – via nature.com.
  106. ^ Zhang, Haiwen; Ly, Kally C. S.; Liu, Xianghui; Chen, Zhihan; Yan, Max; Wu, Zilong; Wang, Xin; Zheng, Yuebeng; Zhou, Han; Fan, Tongxiang (2020). "Biologically inspired flexible photonic films for efficient passive radiative cooling". Applied Physical Sciences. 117 (26): 14657–14666 – via PNAS.
  107. ^ Han, Di; Fei, Jipeng; Li, Hong; Ng, Bing Feng (August 2022). "The criteria to achieving sub-ambient radiative cooling and its limits in tropical daytime". Building and Environment. 221 (1) – via Elsevier Science Direct.
  108. ^ Huang, Jingyuan; Lin, Chongjia; Li, Yang; Huang, Baoling (May 2022). "Effects of humidity, aerosol, and cloud on subambient radiative cooling". International Journal of Heat and Mass Transfer. 186 – via Elsevier Science Direct.
  109. ^ Liu, Junwei; Zhang, Ji; Zhang, Debao; Jiao, Shifei; Xing, Jingcheng; Tang, Huajie; Zhang, Ying; Li, Shuai; Zhou, Zhihua; Zuo, Jian (September 2020). "Sub-ambient radiative cooling with wind cover". Renewable and Sustainable Energy Reviews. 130 – via Elsevier Science Direct.
  110. ^ Akbari, Hashem; et al. (2008). "Global Cooling: Increasing World-wide Urban Albedos to Offset CO2" (PDF). Archived (PDF) from the original on 12 April 2009. Retrieved 29 January 2009.
  111. ^ "The Royal Society" (PDF). royalsociety.org. Archived (PDF) from the original on 21 July 2015. Retrieved 9 November 2015.
  112. ^ Hand, Eric (29 January 2016). "Could bright, foamy wakes from ocean ships combat global warming?". Science. Archived from the original on 31 December 2017. Retrieved 30 December 2017.
  113. ^ Desch, Steven J.; et al. (19 December 2016). "Arctic Ice Management". Earth's Future. 5 (1): 107–127. Bibcode:2017EaFut...5..107D. doi:10.1002/2016EF000410.
  114. ^ McGlynn, Daniel (17 January 2017). "One big reflective band-aid". Berkeley Engineering. University of California, Berkeley. Archived from the original on 31 August 2019. Retrieved 2 January 2018.
  115. ^ Meyer, Robinson (8 January 2018). "A Radical New Scheme to Prevent Catastrophic Sea-Level Rise". The Atlantic. Archived from the original on 1 October 2019. Retrieved 12 January 2018.
  116. ^ "How vast snow cannons could save melting ice sheets". The Independent. 17 July 2019. Archived from the original on 18 July 2019. Retrieved 18 July 2019.
  117. ^ Green, Matthew (17 July 2019). "'Artificial snow' could save stricken Antarctic ice sheet -study". CNBC. Archived from the original on 18 July 2019. Retrieved 18 July 2019.
  118. ^ Hamwey, Robert M. (2005). "Active Amplification of the Terrestrial Albedo to Mitigate Climate Change: An Exploratory Study". Mitigation and Adaptation Strategies for Global Change. 12 (4): 419. arXiv:physics/0512170. Bibcode:2005physics..12170H. doi:10.1007/s11027-005-9024-3. S2CID 118913297.
  119. ^ "A high-albedo diet will chill the planet – environment – 15 January 2009". New Scientist. Archived from the original on 5 October 2013. Retrieved 16 October 2013.
  120. ^ Ridgwell, A; Singarayer, J; Hetherington, A; Valdes, P (2009). "Tackling Regional Climate Change By Leaf Albedo Bio-geoengineering". Current Biology. 19 (2): 146–50. doi:10.1016/j.cub.2008.12.025. PMID 19147356.
  121. ^ J. T. Early (1989). "Space-Based Solar Shield To Offset Greenhouse Effect". Journal of the British Interplanetary Society. Vol. 42. pp. 567–569. This proposal is also discussed in footnote 23 of Teller, Edward; Hyde, Roderick; Wood, Lowell (1997). "Global Warming and Ice Ages: Prospects for Physics-Based Modulation of Global Change" (PDF). Lawrence Livermore National Laboratory. Archived from the original (PDF) on 27 January 2016. Retrieved 21 January 2015. {{cite journal}}: Cite journal requires |journal= (help)
  122. ^ Teller, Edward; Hyde, Roderick; Wood, Lowell (1997). "Global Warming and Ice Ages: Prospects for Physics-Based Modulation of Global Change" (PDF). Lawrence Livermore National Laboratory. Archived from the original (PDF) on 27 January 2016. Retrieved 21 January 2015. See pages 10–14 in particular. {{cite journal}}: Cite journal requires |journal= (help)CS1 maint: postscript (link)
  123. ^ See Russell Dovey, "Supervillainy: Astroengineering Global Warming" Archived 4 August 2012 at archive.today and Bill Christensen, "Reduce Global Warming by Blocking Sunlight" Archived 17 April 2009 at the Wayback Machine.
  124. ^ Keith, David W. (2000). "Geoengineering the climate: History and Prospect". Annual Review of Energy and the Environment. 25 (1): 245–284. doi:10.1146/annurev.energy.25.1.245. S2CID 154687119.
  125. ^ Reynolds, Jesse L. (23 May 2019). The Governance of Solar Geoengineering: Managing Climate Change in the Anthropocene (1 ed.). Cambridge University Press. doi:10.1017/9781316676790. ISBN 978-1-316-67679-0. S2CID 197798234.
  126. ^ Ricke, K. L.; Moreno-Cruz, J. B.; Caldeira, K. (2013). "Strategic incentives for climate geoengineering coalitions to exclude broad participation". Environmental Research Letters. 8 (1): 014021. Bibcode:2013ERL.....8a4021R. doi:10.1088/1748-9326/8/1/014021.
  127. ^ Horton, Joshua (2011). "Geoengineering and the myth of unilateralism: pressures and prospects for international cooperation". Stanford J Law Sci Policy (2): 56–69.
  128. ^ a b Reflecting Sunlight: Recommendations for Solar Geoengineering Research and Research Governance. National Academies of Sciences, Engineering, and Medicine. 25 March 2021. doi:10.17226/25762. ISBN 978-0-309-67605-2. S2CID 234327299. Archived from the original on 17 April 2021. Retrieved 14 April 2021.
  129. ^ Merk, Christine; Pönitzsch, Gert; Kniebes, Carola; Rehdanz, Katrin; Schmidt, Ulrich (10 February 2015). "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.
  130. ^ Burns, Elizabeth T.; Flegal, Jane A.; Keith, David W.; Mahajan, Aseem; Tingley, Dustin; Wagner, Gernot (November 2016). "What do people think when they think about solar geoengineering? A review of empirical social science literature, and prospects for future research: REVIEW OF SOLAR GEOENGINEERING". Earth's Future. 4 (11): 536–542. doi:10.1002/2016EF000461.
  131. ^ Dannenberg, Astrid; Zitzelsberger, Sonja (October 2019). "Climate experts' views on geoengineering depend on their beliefs about climate change impacts". Nature Climate Change. 9 (10): 769–775. Bibcode:2019NatCC...9..769D. doi:10.1038/s41558-019-0564-z. ISSN 1758-678X. PMC 6774770. PMID 31579402.
  132. ^ Carr, Wylie A.; Yung, Laurie (March 2018). "Perceptions of climate engineering in the South Pacific, Sub-Saharan Africa, and North American Arctic". Climatic Change. 147 (1–2): 119–132. Bibcode:2018ClCh..147..119C. doi:10.1007/s10584-018-2138-x. ISSN 0165-0009. S2CID 158821464.
  133. ^ Sugiyama, Masahiro; Asayama, Shinichiro; Kosugi, Takanobu (3 July 2020). "The North–South Divide on Public Perceptions of Stratospheric Aerosol Geoengineering?: A Survey in Six Asia-Pacific Countries". Environmental Communication. 14 (5): 641–656. doi:10.1080/17524032.2019.1699137. ISSN 1752-4032. S2CID 212981798. Archived from the original on 11 June 2021. Retrieved 11 June 2021.
  134. ^ Hamilton, Clive (12 February 2015). "Opinion | The Risks of Climate Engineering". The New York Times. ISSN 0362-4331. Archived from the original on 10 June 2021. Retrieved 11 June 2021.
  135. ^ Reynolds, Jesse L.; Parker, Andy; Irvine, Peter (December 2016). "Five solar geoengineering tropes that have outstayed their welcome: Five solar geoengineering tropes". Earth's Future. 4 (12): 562–568. doi:10.1002/2016EF000416. S2CID 36263104.
  136. ^ "Our position on geoengineering". Environmental Defense Fund. Archived from the original on 27 February 2021. Retrieved 6 June 2021.
  137. ^ "What Is Solar Geoengineering? | Union of Concerned Scientists". www.ucsusa.org. Archived from the original on 20 June 2021. Retrieved 6 June 2021.
  138. ^ Natural Resources Defense Council (June 2019). "Position Statement on Solar Radiation Management" (PDF). Archived (PDF) from the original on 30 July 2021. Retrieved 6 June 2021.
  139. ^ "Geoengineering: Unjust, unproven and risky". Friends of the Earth. Archived from the original on 6 June 2021. Retrieved 6 June 2021.
  140. ^ Rahman, A. Atiq; Artaxo, Paulo; Asrat, Asfawossen; Parker, Andy (April 2018). "Developing countries must lead on solar geoengineering research". Nature. 556 (7699): 22–24. Bibcode:2018Natur.556...22R. doi:10.1038/d41586-018-03917-8. ISSN 0028-0836.
  141. ^ "Solar Radiation Management Governance Initiative". Archived from the original on 11 June 2021. Retrieved 11 June 2021.
  142. ^ Dunleavy, Haley (7 July 2021). "An Indigenous Group's Objection to Geoengineering Spurs a Debate About Social Justice in Climate Science". Inside Climate News. Archived from the original on 19 July 2021. Retrieved 19 July 2021.
  143. ^ "Open letter requesting cancellation of plans for geoengineering related test flights in Kiruna". Sámiráđđi (in Norwegian). Archived from the original on 19 July 2021. Retrieved 19 July 2021.

Further reading[edit]