Solar radiation modification

refer to caption and image description
Schematic with five proposed methods for solar radiation modification technologies

Solar radiation modification or solar radiation management (SRM), also known as solar geoengineering, are planetary-scale approaches to limit global warming by reducing the greenhouse effect, the atmospheric trapping of outgoing thermal radiation that would leave Earth to outer space. SRM includes mainly methods of increasing the reflection of incoming sunlight (solar radiation) by the atmosphere back to space. Among the multiple potential approaches, stratospheric aerosol injection (SAI) is the most-studied,[1]: 350  followed by marine cloud brightening (MCB). SRM also includes ground-based albedo modification (GBAM).[1]: 348  Space-based concepts, such as space sunshades and space mirrors, are not currently included in the IPCC Sixth Assessment Report as a relevant option.[2] SRM is a form of climate engineering. It could be a supplement but would not be a substitute to the main climate change mitigation measures,[2] reducing greenhouse gas emissions and removing greenhouse gases from the atmosphere.

Scientific studies, based on evidence from climate models, have generally shown that some forms of SRM could in theory reduce global warming and therefore many effects of climate change.[3][4][5] 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.[2] SRM would therefore pose environmental risks.

Governing SRM is challenging for multiple reasons, including that several countries would likely be capable of doing it alone.[6] For now, there is no formal international framework designed to regulate SRM, although aspects of existing international law would be applicable. Issues of governance and effectiveness are intertwined, as poorly governed use of SRM might lead to its highly suboptimal implementation.[7] Thus, many questions regarding the acceptable deployment of SRM, or even its research and development, are currently unanswered. In 2022, a dozen academics launched a campaign for national policies of "no public funding, no outdoor experiments, no patents, no deployment, and no support in international institutions... including in assessments by the Intergovernmental Panel on Climate Change."[8] As of December 2024, nearly 540 academics[9] and 60 advocacy organizations[10] have endorsed the proposal.

According to Bloomberg News, as of 2024 several American billionaires are funding research into SRM: "A growing number of Silicon Valley founders and investors are backing research into blocking the sun by spraying reflective particles high in the atmosphere or making clouds brighter."[11]

Context

See also: Causes of climate change, Global surface temperature, and Greenhouse effect
Potential complementary responses to climate change: greenhouse gas emissions abatement, carbon dioxide removal, SRM, and adaptation.[12]

The context for the interest in solar radiation modification (SRM) options is continued high global emissions of greenhouse gases. Human's greenhouse gas emissions have disrupted the Earth's energy budget. 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, or "radiative forcing," means that the Earth absorbs more energy than it emits, causing global temperatures to rise[14] which will, in turn, have negative impacts on humans and nature.

In principle, net emissions could be reduced and even eliminated achieved through a combination of emission cuts and carbon dioxide removal (together called "mitigation"). However, emissions have persisted, consistently exceeding targets, and experts have raised serious questions regarding the feasibility of large-scale removals.[15][16][17] The 2023 Emissions Gap Report from the UN Environment Programme estimated that even the most optimistic assumptions regarding countries' current conditional emissions policies and pledges has only a 14% chance of limiting global warming to 1.5 °C.[18]

SRM would increase Earth's reflection of sunlight by increasing the albedo of the atmosphere or the surface. An increase in planetary albedo of 1% would reduce radiative forcing by 2.35 W/m2, eliminating most of global warming from current anthropogenically elevated greenhouse gas concentrations, while a 2% albedo increase would negate the warming effect of doubling the atmospheric carbon dioxide concentration.[19]

SRM could theoretically buy time by slowing the rate of climate change or to eliminate the worst climate impacts until net negative emissions reduce atmospheric greenhouse gas concentrations sufficiently.[citation needed] This is because SRM could, unlike the other responses, cool the planet within months after deployment.[20]

SRM is generally intended to complement, not replace, emissions reduction and carbon dioxide removal. For example, the IPCC Sixth Assessment Report says: "There is high agreement in the literature that for addressing climate change risks SRM cannot be the main policy response to climate change and is, at best, a supplement to achieving sustained net zero or net negative CO2 emission levels globally".[2]

Major reports on SRM that have investigated advantages and disadvantages of SRM (sometimes grouped with carbon dioxide removal and under the title of climate engineering) include those by the Royal Society (2009),[19] the US National Academies (2015 and 2021),[20][21] the UN Environment Programme (2023),[4] and the European Union's Scientific Advice Mechanism (2024).[22]

History

In 1965, during the administration of U.S. President Lyndon B. Johnson, the President's Science Advisory Committee delivered Restoring the Quality of Our Environment, the first report which warned of the harmful effects of carbon dioxide emissions from fossil fuel. To counteract global warming, the report mentioned "deliberately bringing about countervailing climatic changes", including "raising the albedo, or reflectivity, of the Earth".[23][24]

In 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.[25][26] Along with carbon dioxide removal, SRM was discussed jointly as geoengineering in a 1992 climate change report from the US National Academies.[27]

David Keith, an American physicist, has worked on solar geoengineering since 1992, when he and Hadi Dowlatabadi published one of the first assessments of the technology and its policy implications, introducing a structured comparison of cost and risk. Keith has consistently argued that geoengineering needs a "systematic research program" to determine whether or not its approaches are feasible.[28][29][30] He has also appealed for international standards of governance and oversight for how such research might proceed.[31]

The first modeled results of SRM were published in 2000.[32] In 2006 Nobel Laureate Paul Crutzen published an influential scholarly paper where he said, "Given the grossly disappointing international political response to the required greenhouse gas emissions, and further considering some drastic results of recent studies, research on the feasibility and environmental consequences of climate engineering [...] should not be tabooed."[33]

Atmospheric methods

The atmospheric methods for SRM include stratospheric aerosol injection (SAI), marine cloud brightening (MCB) and cirrus cloud thinning (CCT).[1]: 348 

Stratospheric aerosol injection (SAI)

Pinatubo eruption cloud: This volcano released huge quantities of stratospheric sulfur aerosols, and this event contributed greatly to understanding of stratospheric aerosol injection (SAI)
Main article: Stratospheric aerosol injection

For stratospheric aerosol injection (SAI) small particles would be injected into the upper atmosphere to cool the planet with both global dimming and increased albedo. Of all the proposed SRM methods, SAI has received the most sustained attention: The IPCC concluded in 2018 that SAI "is the most-researched SRM method, with high agreement that it could limit warming to below 1.5 °C."[1]: 350  This technique would mimic a cooling phenomenon that occurs naturally by the eruption of volcanoes.[34] 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.[35][36][37][38][39] Delivery by custom aircraft appears most feasible, with artillery and balloons sometimes discussed.[40][41][42]

This technique could give much more than 3.7 W/m2 of globally averaged negative forcing,[43] which is sufficient to entirely offset the warming caused by a doubling of carbon dioxide.

The most recent Scientific Assessment of Ozone Depletion report in 2022 from the World Meteorological Organization concluded "Stratospheric Aerosol Injection (SAI) has the potential to limit the rise in global surface temperatures by increasing the concentrations of particles in the stratosphere... . However, SAI comes with significant risks and can cause unintended consequences."[5]

A potential disadvantage of SAI is its potential to catalyze the destruction of the protective stratospheric ozone layer.[44][45]

Marine cloud brightening (MCB)

Main article: Marine cloud brightening

Marine cloud brightening (MCB) would involve spraying fine sea water to whiten clouds and thus increase cloud reflectivity. It would work by "seeding to promote nucleation, reducing optical thickness and cloud lifetime, to allow more outgoing longwave radiation to escape into space".[1]: 348 

The extra condensation nuclei created by the spray would change the size distribution of the drops in existing clouds to make them whiter.[46] 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.[47] 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,[43] which is sufficient to reverse the warming effect of a doubling of atmospheric carbon dioxide concentration.

Cirrus cloud thinning (CCT)

Main article: Cirrus cloud thinning
Cirrus clouds merging to cirrocumulus clouds

Cirrus cloud thinning (CCT) involves "seeding to promote nucleation, reducing optical thickness and cloud lifetime, to allow more outgoing longwave radiation to escape into space."[1]: 348 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 SRM, 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 SRM methods, it is often included.[21]

Other methods

Ground-based albedo modification (GBAM)

Main article: Reflective surfaces (climate engineering)

The IPCC describes ground-based albedo modification (GBAM) as "whitening roofs, changes in land use management (e.g., no-till farming), change of albedo at a larger scale (covering glaciers or deserts with reflective sheeting and changes in ocean albedo)."[1]: 348  It is a method of enhancing Earth's albedo, i.e. the ability to reflect the visible, infrared, and ultraviolet wavelengths of the Sun, reducing heat transfer to the surface.

Space-based

The basic function of a space lens to mitigate global warming. The image is simplified, as a 1000 kilometre diameter lens is considered sufficient by most proposals, and would be much smaller than shown. Additionally, a zone plate would only be a few nanometers thick.
Main articles: Space sunshade and Space mirror (climate engineering)

There are some proponents who argue that unlike stratospheric aerosol injection, space-based approaches are advantageous because they do not interfere directly with the biosphere and ecosystems.[48] However, space-based approaches would cost about 1000 times more than their terrestrial alternatives.[49] In 2022, the IPCC Sixth Assessment Report discussed SAI, MCB, CCT and even attempts to alter albedo on the ground or in the ocean, yet completely ignored space-based approaches.[2]

There has been a range of proposals to reflect or deflect solar radiation from space, before it even reaches the atmosphere, commonly described as a space sunshade.[36] The most straightforward is to have mirrors orbiting around the Earth—an idea first suggested even before the wider awareness of climate change, with rocketry pioneer Hermann Oberth considering it a way to facilitate terraforming projects in 1923.[50] and this was followed by other books in 1929, 1957 and 1978.[51][52][53] By 1992, the U.S. National Academy of Sciences described a plan to suspend 55,000 mirrors with an individual area of 100 square meters in a Low Earth orbit.[19] Another contemporary plan was to use space dust to replicate Rings of Saturn around the equator, although a large number of satellites would have been necessary to prevent it from dissipating. A 2006 variation on this idea suggested relying entirely on a ring of satellites electromagnetically tethered in the same location. In all cases, sunlight exerts pressure which can displace these reflectors from orbit over time, unless stabilized by enough mass. Yet, higher mass immediately drives up launch costs.[19]

In an attempt to deal with this problem, other researchers have proposed Inner lagrangian point between the Earth and the Sun as an alternative to near-Earth orbits, even though this tends to increase manufacturing or delivery costs instead. In 1989, a paper suggested founding a lunar colony, which would produce and deploy diffraction grating made out of a hundred million tonnes of glass.[54] In 1997, a single, very large mesh of aluminium wires "about one millionth of a millimetre thick" was also proposed.[55][self-published source?] Two other proposals from the early 2000s advocated the use of thin metallic disks 50–60 cm in diameter, which would either be launched from the Earth at a rate of once per minute over several decades, or be manufactured from asteroids directly in orbit.[19]

When summarizing these options in 2009, the Royal Society concluded that their deployment times are measured in decades and costs in the trillions of USD, meaning that they are "not realistic potential contributors to short-term, temporary measures for avoiding dangerous climate change", and may only be competitive with the other geoengineering approaches when viewed from a genuinely long (a century or more) perspective, as the long lifetime of L1-based approaches could make them cheaper than the need to continually renew atmospheric-based measures over that timeframe.[19]

In 2021, researchers in Sweden considered building solar sails in the near-Earth orbit, which would then arrive to L1 point over 600 days one by one. Once they all form an array in situ, the combined 1.5 billion sails would have total area of 3.75 million square kilometers, while their combined mass is estimated in a range between 83 million tons (present-day technology) and 34 million tons (optimal advancements). This proposal would cost between five and ten trillion dollars, but only once launch cost has been reduced to US$50/kg, which represents a massive reduction from the present-day costs of $4400–2700/kg[56] for the most widely used launch vehicles.[57]

In July 2022, a pair of researchers from MIT Senseable City Lab, Olivia Borgue and Andreas M. Hein, have instead proposed integrating nanotubes made out of silicon dioxide into ultra-thin polymeric films (described as "space bubbles" in the media [48]), whose semi-transparent nature would allow them to resist the pressure of solar wind at L1 point better than any alternative with the same weight. The use of these "bubbles" would limit the mass of a distributed sunshade roughly the size of Brazil to about 100,000 tons, much lower than the earlier proposals. However, it would still require between 399 and 899 yearly launches of a vehicle such as SpaceX Starship for a period of around 10 years, even though the production of the bubbles themselves would have to be done in space. The flights would not begin until research into production and maintenance of these bubbles is completed, which the authors estimate would require a minimum of 10–15 years. After that, the space shield may be large enough by 2050 to prevent crossing of the 2 °C (3.6 °F) threshold.[49][48][58]

In 2023, three astronomers revisited the space dust concept, instead advocating for a lunar colony which would continuously mine the Moon in order to eject lunar dust into space on a trajectory where it would interfere with sunlight streaming towards the Earth. Ejections would have to be near-continuous, as since the dust would scatter in a matter of days, and about 10 million tons would have to be dug out and launched annually.[59] The authors admit that they lack a background in either climate or rocket science, and the proposal may not be logistically feasible.[60]

Costs

Cost estimates for SAI

This section is an excerpt from Stratospheric aerosol injection § Cost.[edit]

A study in 2020 looked at the cost of SAI through to the year 2100. It found that relative to other climate interventions and solutions, SAI remains inexpensive. However, at about $18 billion per year per degree Celsius of warming avoided (in 2020 USD), a solar geoengineering program with substantial climate impact would lie well beyond the financial reach of individuals, small states, or other non-state potential rogue actors.[61] The annual cost of delivering a sufficient amount of sulfur to counteract expected greenhouse warming is estimated at $5–10 billion US dollars.[61]

SAI is expected to have low direct financial costs of implementation,[62] relative to the expected costs of both unabated climate change and aggressive mitigation.

Technical problem areas

See also: Stratospheric aerosol injection § Problematic aspects

Aspects of regional scales and seasonal timescales

A moderate magnitude of SRM would bring important aspects of the climate—for example, average and extreme temperature, water availability, and cyclone intensity—closer to their preindustrial values for most of the planet at a subregional resolution.[63] Furthermore, SRM's effect would occur rapidly, unlike those of other responses to climate change. However, even under optimal implementation, some climatic anomalies—especially regarding precipitation—would persist, although mostly at lesser magnitudes than without SRM.[citation needed]

As well as imperfect and geographically uneven cancellation of the climatic effect of greenhouse gases, SRM has other significant technical problems. The IPCC Sixth Assessment Report explains some of the risks and uncertainties as follows: "[...] 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."[64]: 69 [3]

Likewise, a 2023 report from the UN Environment Programme stated, "Climate model results indicate that an operational SRM deployment could fully or partially offset the global mean warming caused by anthropogenic GHG emissions and reduce some climate change hazards in most regions. There could be substantial residual or possible overcompensating climate change at regional scales and seasonal timescales."[4]: 14  The report also said: "An operational SRM deployment would introduce new risks to people and ecosystems".[4]: 1 

SRM would imperfectly compensate for anthropogenic climate changes. Greenhouse gases warm throughout the globe and year, whereas SRM 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.[65][66]

Impacts on precipitation

Models indicate that SRM would compensate more effectively for temperature than for precipitation.[citation needed] Therefore, using SRM 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,[citation needed] but this would depend on the intensity (i.e. radiative forcing) of SRM. Furthermore, soil moisture is more important for plants than average annual precipitation. Because SRM would reduce evaporation, it more precisely compensates for changes to soil moisture than for average annual precipitation.[67] Likewise, the intensity of tropical monsoons is increased by climate change and decreased by SRM.[68]

A net reduction in tropical monsoon intensity might manifest at moderate use of SRM, although to some degree the effect of this on humans and ecosystems would be mitigated by greater net precipitation outside of the monsoon system.[citation needed] This has led to claims that SRM "would disrupt the Asian and African summer monsoons", but the impact would depend on the particular implementation regime.[citation needed]

Maintenance and termination shock

The direct climatic effects of SRM are reversible within short timescales.[20] Models project that SRM interventions would take effect rapidly, but would also quickly fade out if not sustained.[69] If SRM masked significant warming, stopped abruptly, and was not resumed within a year or so, the climate would rapidly warm towards levels which would have existed without the use of SRM, sometimes known as termination shock.[70] 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 appears preventable because it would be in states' interest to resume any terminated deployment regime, and because infrastructure and knowledge could be made redundant and resilient.[71][72]

Failure to reduce ocean acidification

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.

SRM does not directly influence atmospheric carbon dioxide concentration and thus does not reduce ocean acidification.[73] While not a risk of SRM per se, this points to the limitations of relying on it to the exclusion of emissions reduction.

Effect on sky and clouds

Managing solar radiation using aerosols or cloud cover would involve changing the ratio between direct and indirect solar radiation. This would affect plant life[74] and solar energy.[75] 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.[76] As a result, deployment of atmospheric SRM would reduce by at least 2–5% the growth rates of phytoplankton, trees, and crops [77] between now and the end of the century.[78] Uniformly reduced net shortwave radiation would hurt solar photovoltaics by the same >2–5% because of the bandgap of silicon photovoltaics.[79]

Uncertainty regarding effects

Much uncertainty remains about SRM's likely effects.[73] Most of the evidence regarding SRM's expected effects comes from climate models and volcanic eruptions. Some uncertainties in climate models (such as aerosol microphysics, stratospheric dynamics, and sub-grid scale mixing) are particularly relevant to SRM and are a target for future research.[80] Volcanoes are an imperfect analogue as they release the material in the stratosphere in a single pulse, as opposed to sustained injection.[81]

Climate change has various effects on agriculture. One of them is the CO2 fertilization effect which affects different crops in different ways. A net increase in agricultural productivity from SRM has been predicted by some studies due to the combination of more diffuse light and carbon dioxide's fertilization effect.[82] Other studies suggest that SRM would have little net effect on agriculture.[83]

There have also been proposals to focus SRM at the poles, in order to combat sea level rise[84] or regional marine cloud brightening (MCB) in order to protect coral reefs from bleaching. However, there is low confidence about the ability to control geographical boundaries of the effect.[2]

SRM might be used in ways that are not optimal. In particular, SRM's climatic effects would be rapid and reversible, which would bring the disadvantage of sudden warming if it were to be stopped suddenly.[85] Similarly, if SRM was very heterogenous, then the climatic responses could be severe and uncertain.

Governance and policy risks

Global governance issues

The potential use of SRM poses several governance challenges because of its high leverage, low apparent direct costs, and technical feasibility as well as issues of power and jurisdiction.[86] Because international law is generally consensual, this creates a challenge of widespread participation being required. Key issues include who will have control over the deployment of SRM and under what governance regime the deployment can be monitored and supervised. A governance framework for SRM 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.

Frank Biermann and other political scientists argue that the current international political system is inadequate for the fair and inclusive governance of SRM deployment on a global scale.[7] Other researchers have suggested that building a global agreement on SRM deployment will be very difficult, and instead power blocs are likely to emerge.[87] There are, however, significant incentives for states to cooperate in choosing a specific SRM policy, which make unilateral deployment a rather unlikely event.[88]

Other relevant aspects of the governance of SRM include supporting research, ensuring that it is conducted responsibly, regulating the roles of the private sector and (if any) the military, public engagement, setting and coordinating research priorities, undertaking trusted scientific assessment, building trust, and compensating for possible harms.

Although climate models of SRM rely on some optimal or consistent implementation, leaders of countries and other actors may disagree as to whether, how, and to what degree SRM be used. This could result in suboptimal deployments and exacerbate international tensions.[89] Likewise, blame for perceived local negative impacts from SRM could be a source of international tensions.[90]

There is a risk that countries may start using SRM without proper precaution or research. SRM, at least by stratospheric aerosol injection, appears to have low direct implementation costs relative to its potential impact, and many countries have the financial and technical resources to undertake SRM.[6] Some have suggested that SRM could be within reach of a lone "Greenfinger", a wealthy individual who takes it upon him or herself to be the "self-appointed protector of the planet".[91] Others argue that states will insist on maintaining control of SRM.[92]

Lessened climate change mitigation

See also: Climate change mitigation

The existence of SRM may reduce the political and social impetus for climate change mitigation.[93] This has often been called a potential "moral hazard", although such language is not precise. Some modelling work suggests that the threat of SRM may in fact increase the likelihood of emissions reduction.[94][95][96][97]

Advocacy for SRM

The leading argument supportive of SRM research is that the risks of likely anthropogenic climate change are great and imminent enough to warrant research and evaluation of a wide range of responses, even one with limitations and risks of its own. Leading this effort have been some climate scientists (such as James Hansen), some of whom have endorsed one or both public letters that support further SRM research.[98][99]

Scientific organizations that have called for further research in SRM include:

In 2024, Professor David Keith stated that in the last year or so, there has been far more engagement with SRM from senior political leaders than was previously the case.[108]

Some nongovernmental organizations actively support SRM research and governance dialogues. The Degrees Initiative is a UK registered charity, established to build capacity in developing countries to evaluate SRM.[109] It works toward "changing the global environment in which SRM is evaluated, ensuring informed and confident representation from developing countries."[109] However, the German NGO Geoengineering Monitor has criticized The Degrees Initiative for "being an organisation based in the Global North imposing its research agenda onto the Global South" as well as "normalising and legitimising solar geoengineering as a viable mitigation strategy". They also point out that it is "predominantly funded by foundations run by technology and finance billionaires based in the Global North".[110]

SilverLining is an American organization that advances SRM research as part of "climate interventions to reduce near-term climate risks and impacts."[111] It is funded by "philanthropic foundations and individual donors focused on climate change".[111][112]

The Alliance for Just Deliberation on Solar Geoengineering advances "just and inclusive deliberation" regarding SRM.[113] The Carnegie Climate Governance Initiative catalyzed governance of SRM and carbon dioxide removal,[114] although it ended operations in 2023.

Critics point out that some climate change deniers or former climate change deniers are now actively supporting research in SRM. One example is Danish author Bjorn Lomborg, who "poo-pooed the effects of climate change until he became a geoengineering proponent".[115] Another example is Newt Gingrich, an American politician.[115]

The fossil fuels lobby is among those who advocate for SRM research.[116][117] However, others say that "Concluding that advocacy of SRM research originates from climate deniers and oil executives is perhaps understandable but untrue".[118]

Opposition to deployment and research

Opposition to SRM has come from various academics and NGOs.[8] The most common concern is that SRM could lessen climate change mitigation efforts. Opponents of SRM research often emphasize that reductions of greenhouse gas emissions would also bring co-benefits (for example reduced air pollution) and that consideration of SRM could prevent these outcomes.[119]

The ETC Group, an environmental justice organization, has been a pioneer in opposing SRM research.[120] It was later joined by the Heinrich Böll Foundation[121] (affiliated with the German Green Party) and the Center for International Environmental Law.[122] The German NGO Geoengineering Monitor (funded through a collaboration between ETC Group, Biofuelwatch and the Heinrich Boell Foundation) has the goal to "serve as a resource for civil society, policy-makers, journalists and the wider public in order to support advocacy work that opposes geoengineering and aims to address the root causes of climate change instead".[123]

In 2021, researchers at Harvard put plans for a SRM test on hold after Indigenous Sámi people objected to the test taking place in their homeland.[124][125] Although the test would not have involved any atmospheric experiments, members of the Saami Council spoke out against the lack of consultation and SRM 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."

By 2024, U.S. government agencies were operating an airborne early warning system for detecting small concentrations of aerosols to determine where other countries might be carrying out geoengineering attempts, thought to have unpredictable effects on climate.[126]

The Climate Overshoot Commission is a group of global, eminent, and independent figures.[127] It investigated and developed a comprehensive strategy to reduce climate risks. The Commission is not supporting deployment of SRM. In fact, it recommends a "a moratorium on the deployment of solar radiation modification (SRM) and large-scale outdoor experiment". But it also says that "governance of SRM research should be expanded".[128]: 15 

Proposed international non-use agreement on solar geoengineering

In 2022, a dozen academics launched a campaign for national policies of "no public funding, no outdoor experiments, no patents, no deployment, and no support in international institutions... including in assessments by the Intergovernmental Panel on Climate Change."[8] The proponents call this an International Non-Use Agreement on Solar Geoengineering.

The advocates’ core argument is that, because SRM would be global in effect and some countries are much more powerful than others, it is “not governable in a globally inclusive and just manner within the current international political system.”[8] They therefore oppose the “normalization” of SRM and call on countries, intergovernmental organizations, and others to adopt the proposal’s five elements.

On the day that the academic article was published, the authors also launched a campaign calling for others to endorse the proposal.[129] Their open letter emphasized, in addition to the governance challenges, that SRM’s risks are “poorly understood and can never be fully known” and that its potential would threaten commitments to reducing greenhouse gas emissions.[130] As of December 2024, nearly 540 academics[9] and 60 advocacy organizations[10] have endorsed the proposal. Among the latter is Climate Action Network, itself a coalition of more than 1900 political organizations. The position from Climate Action Network included a footnote that excluded the Environmental Defense Fund and the Natural Resources Defense Council.[131]

Research funding

As of 2018, total research funding worldwide remained modest, at less than 10 million US dollars annually.[132] Almost all research into SRM has to date consisted of computer modeling or laboratory tests,[133] and there are calls for more research funding as the science is poorly understood.[134][21]: 17 

A study from 2022 investigated where the funding for solar geoengineering (SG) came from globally. The authors concluded "the primary funders of SG research do not emanate from fossil capital" and that there are "close ties to mostly US financial and technological capital as well as a number of billionaire philanthropists".[135]

Country activities

Few countries have an explicit governmental position on SRM. Those that do, such as the United Kingdom[136] and Germany,[137]: 58  support some SRM research even if they do not see it as a current climate policy option. For example, the German Federal Government does have an explicit position on SRM and stated in 2023 in a strategy document climate foreign policy: "Due to the uncertainties, implications and risks, the German Government is not currently considering solar radiation management (SRM) as a climate policy option". The document also stated: "Nonetheless, in accordance with the precautionary principle we will continue to analyse and assess the extensive scientific, technological, political, social and ethical risks and implications of SRM, in the context of technology-neutral basic research as distinguished from technology development for use at scale".[137]: 58 

Major academic institutions, including Harvard University, have begun research into SRM,[138] with NOAA alone investing $22 million from 2019 to 2022, though few outdoor tests have been run to date.[139]

Some countries, such as the U.S., Germany, China, Finland, Norway, and Japan, as well as the European Union, have funded SRM research.[140]

In 2021, the National Academies of Sciences, Engineering, and Medicine released their consensus study report Recommendations for Solar Geoengineering Research and Research Governance. The report recommended an initial investment into SRM research of $100–200 million over five years.[21]: 17 

International collaborations

Under the World Climate Research Programme there is a Lighthouse Activity called Research on Climate Intervention as of 2024. This will include research on all possible climate interventions (another term for climate engineering): "large-scale Carbon Dioxide Removal (CDR; also known as Greenhouse Gas Removal, or Negative Emissions Technologies) and Solar Radiation Modification (SRM; also known as Solar Reflection Modification, Albedo Modification, or Radiative Forcing Management)".[141]

Philanthropic and venture capitalist activities

There are also research activities on SRM that are funded by philanthropy. According to Bloomberg News, as of 2024 several American billionaires are funding research into SRM: "A growing number of Silicon Valley founders and investors are backing research into blocking the sun by spraying reflective particles high in the atmosphere or making clouds brighter."[11] The article listed the following billionaires as being notable geoengineering research supporters: Mike Schroepfer, Sam Altman, Matt Cohler, Rachel Pritzker, Bill Gates, Dustin Moskovitz.

SRM research initiatives, or non-profit knowledge hubs, include for example SRM360 which is "supporting an informed, evidence-based discussion of sunlight reflection methods (SRM)".[142] Funding comes from the LAD Climate Fund.[143][144] David Keith, a long-term proponent of SRM,[28][29][30] is one of the members of the advisory board.[145]

Another example is Reflective, which is "a philanthropically-funded initiative focused on sunlight reflection research and technology development".[146] Their funding is "entirely by grants or donations from a number of leading philanthropies focused on addressing climate change": Outlier Projects, Navigation Fund, Astera Institute, Open Philanthropy, Crankstart, Matt Cohler, Richard and Sabine Wood.[146]

Deployment activities

Some startups in the private sector have secured funding for potential SRM deployment. One such example is Make Sunsets,[147] which began launching balloons containing helium and sulfur dioxide. The startup sells cooling credits, claiming that each US$10 credit would offset the warming effect of one ton of carbon dioxide warming for a year.[148] Based in California, Make Sunsets conducted some of its activities in Mexico. In response to these activities, which were conducted without prior notification or consent, the Mexican government announced measures to prohibit SRM experiments within its borders.[149] Even people who advocate for more research into SRM have criticized Make Sunsets' undertaking.[108]

Mexico has announced that it will prohibit "experimental practices with solar geoengineering",[149] although it remains unclear what this policy will include and whether the policy has actually been implemented.

Society and culture

There have been a handful of studies into attitudes to and opinions of SRM. These generally find low levels of awareness, uneasiness with the implementation of SRM, cautious support of research, and a preference for greenhouse gas emissions reduction.[150][151] 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.[152][153][154]

The largest assessment of public opinion and perception of SRM, which had over 30,000 respondents in 30 countries, found that "Global South publics are significantly more favorable about potential benefits and express greater support for climate-intervention technologies." Though the assessment also found Global South publics had greater concern the technologies could undermine climate-mitigation.[155]

In the film Snowpiercer, as well as in the television spin-off, an apocalyptic global ice-age is caused by the introduction of a fictional substance, dubbed, CW-7 into the atmosphere, with the intention of preventing global-warming by blocking out the light of the sun.[156][157]

In the novel The Ministry for the Future by Kim Stanley Robinson, stratospheric aerosol injection is used by the Indian Government as a climate mitigation measure following a catastrophic and deadly heatwave.[158]

The novel Termination Shock by Neal Stephenson revolves around a private initiative by a billionaire, with covert support or opposition from some national governments, to inject sulfur into the stratosphere using recoverable gliders launched with a gun.[159]

See also

References

  1. ^ a b c d e f g de Coninck, H., A. Revi, M. Babiker, P. Bertoldi, M. Buckeridge, A. Cartwright, W. Dong, J. Ford, S. Fuss, J.-C. Hourcade, D. Ley, R. Mechler, P. Newman, A. Revokatova, S. Schultz, L. Steg, and T. Sugiyama, 2018: Strengthening and Implementing the Global Response. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [MassonDelmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)]. In Press. Pg. 348.
  2. ^ a b c d e f 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.)].
  3. ^ a b Intergovernmental Panel on Climate Change (IPCC) (6 July 2023). 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.
  4. ^ a b c d e UNEP (2023). "One Atmosphere: An Independent Expert Review on Solar Radiation Modification Research and Deployment". UNEP - UN Environment Programme. Retrieved 9 March 2024.
  5. ^ a b World Meteorological Organization (WMO) (2022). Scientific Assessment of Ozone Depletion: 2022. Geneva: WMO. ISBN 978-9914-733-99-0.
  6. ^ a b Gernot Wagner (2021). Geoengineering: the Gamble.
  7. ^ a b Biermann, Frank; Oomen, Jeroen; Gupta, Aarti; Ali, Saleem H.; Conca, Ken; Hajer, Maarten A.; Kashwan, Prakash; Kotzé, Louis J.; Leach, Melissa; Messner, Dirk; Okereke, Chukwumerije; Persson, Åsa; Potočnik, Janez; Schlosberg, David; Scobie, Michelle (2022). "Solar geoengineering: The case for an international non-use agreement". WIREs Climate Change. 13 (3). Bibcode:2022WIRCC..13E.754B. doi:10.1002/wcc.754. ISSN 1757-7780.
  8. ^ a b c d Biermann, Frank; Oomen, Jeroen; Gupta, Aarti; Ali, Saleem H.; Conca, Ken; Hajer, Maarten A.; Kashwan, Prakash; Kotzé, Louis J.; Leach, Melissa; Messner, Dirk; Okereke, Chukwumerije; Persson, Åsa; Potočnik, Janez; Schlosberg, David; Scobie, Michelle (May 2022). "Solar geoengineering: The case for an international non-use agreement". WIREs Climate Change. 13 (3). Bibcode:2022WIRCC..13E.754B. doi:10.1002/wcc.754. ISSN 1757-7780.
  9. ^ a b "Signatories". Solar Geoengineering Non-Use Agreement. Retrieved 14 March 2024.
  10. ^ a b "Endorsements". Solar Geoengineering Non-Use Agreement. Retrieved 14 March 2024.
  11. ^ a b "Silicon Valley's Elite Pour Money Into Blotting Out the Sun". Bloomberg.com. 25 October 2024. Retrieved 10 December 2024.
  12. ^ 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.
  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. ^ Hansson, Anders; Anshelm, Jonas; Fridahl, Mathias; Haikola, Simon (29 April 2021). "Boundary Work and Interpretations in the IPCC Review Process of the Role of Bioenergy With Carbon Capture and Storage (BECCS) in Limiting Global Warming to 1.5°C". Frontiers in Climate. 3. doi:10.3389/fclim.2021.643224.
  16. ^ Fuhrman, Jay; McJeon, Haewon; Doney, Scott C.; Shobe, William; Clarens, Andres F. (4 December 2019). "From Zero to Hero?: Why Integrated Assessment Modeling of Negative Emissions Technologies Is Hard and How We Can Do Better". Frontiers in Climate. 1. doi:10.3389/fclim.2019.00011.
  17. ^ Carton, Wim (13 November 2020). Carbon Unicorns and Fossil Futures: Whose Emission Reduction Pathways Is the IPCC Performing?. pp. 34–49. doi:10.36019/9781978809390-003. ISBN 978-1-9788-0939-0. Retrieved 24 August 2024. {{cite book}}: |website= ignored (help)
  18. ^ Environment, U. N. (8 November 2023). "Emissions Gap Report 2023". UNEP - UN Environment Programme. Retrieved 10 June 2024.
  19. ^ a b c d e f g The Royal Society (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.
  20. ^ a b c d National Research Council (10 February 2015). Climate Intervention: Reflecting Sunlight to Cool Earth -Committee on Geoengineering Climate: Technical Evaluation Discussion of Impacts; National Research Council (U.S.) Division On Earth And Life Studies National Research Council (U.S.) Ocean Studies Board: Board on Atmospheric Sciences Climate. The National Academies Press. ISBN 9780309314824. Archived from the original on 14 December 2019. Retrieved 11 September 2015 – via www.nap.edu.
  21. ^ a b c d e 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 17 April 2021.
  22. ^ Scientific Advice Mechanism to the European Commission (9 December 2024). Solar radiation modification: evidence review report (Report). SAPEA. doi:10.5281/zenodo.14283096.
  23. ^ President’s Science Advisory Committee, Environmental Pollution Panel (1 November 1965). Restoring the Quality of Our Environment. Washington: U.S. Government Printing Office.{{cite book}}: CS1 maint: date and year (link)
  24. ^ "Geoengineering: A Short History". Foreign Policy. 2013. Archived from the original on 22 May 2019. Retrieved 7 June 2021.
  25. ^ Budyko, M. I. (1977). Climatic changes. Washington: American Geophysical Union. ISBN 978-0-87590-206-7.
  26. ^ Budyko, M. I. (1977). "On present-day climatic changes". Tellus. 29 (3): 193–204. doi:10.1111/j.2153-3490.1977.tb00725.x.
  27. ^ 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.
  28. ^ a b Kintisch, Eli (18 October 2013). "Dr. Cool" (PDF). Science. 342 (6156): 307–309. Bibcode:2013Sci...342..307K. doi:10.1126/science.342.6156.307. PMID 24136948. Retrieved 30 June 2021.
  29. ^ a b O'Donnell, Erin (2013). "Buffering the Sun: David Keith and the question of climate engineering". Harvard Magazine. No. July–August. Retrieved 7 July 2021.
  30. ^ a b Keith, David W.; Dowlatabadi, Hadi (7 July 1992). "A Serious Look at Geoengineering" (PDF). Eos, Transactions American Geophysical Union. 73 (27): 289 and 292–293. Bibcode:1992EOSTr..73..289K. doi:10.1029/91eo00231. Archived from the original (PDF) on 1 October 2015. Retrieved 30 September 2015.
  31. ^ Lieberman, Bruce (2 November 2016). "Geoengineering: crazy...with a big 'but'". Yale Climate Connections. Retrieved 5 February 2018.
  32. ^ Govindasamy, Bala; Caldeira, Ken (15 July 2000). "Geoengineering Earth's radiation balance to mitigate CO 2 ‐induced climate change". Geophysical Research Letters. 27 (14): 2141–2144. doi:10.1029/1999GL006086. ISSN 0094-8276.
  33. ^ 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.
  34. ^ 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.
  35. ^ Mason, Betsy (16 September 2020). "Why solar geoengineering should be part of the climate crisis solution". Knowable Magazine. doi:10.1146/knowable-091620-2.
  36. ^ a b 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.
  37. ^ 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.
  38. ^ 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:2015ACP....1511835W. doi:10.5194/acpd-15-11799-2015.
  39. ^ A. J. Ferraro; A. J. Charlton-Perez; E. J. Highwood (2015). "Stratospheric dynamics and midlatitude jets under geoengineering with space mirrors and sulfate and titania aerosols" (PDF). Journal of Geophysical Research: Atmospheres. 120 (2): 414–429. Bibcode:2015JGRD..120..414F. doi:10.1002/2014JD022734. hdl:10871/16214. S2CID 33804616.
  40. ^ 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.
  41. ^ 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.
  42. ^ "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.
  43. ^ a b 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.
  44. ^ Intergovernmental Panel on Climate Change (IPCC) (22 June 2023). Climate Change 2022 – Impacts, Adaptation and Vulnerability: Working Group II Contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (1 ed.). Cambridge University Press. p. 2476. doi:10.1017/9781009325844.025. ISBN 978-1-009-32584-4.
  45. ^ Haywood, James; Tilmes, Simone (2022). "Chapter 6: Stratospheric aerosol injection and its potential effect on the stratospheric ozone layer". Scientific assessment of ozone depletion. World Meteorological Organization. pp. 325–383.
  46. ^ Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base: Panel on Policy Implications of Greenhouse Warming, National Academy of Sciences, National Academy of Engineering, Institute of Medicine. The National Academies Press. 1992. doi:10.17226/1605. ISBN 978-0-585-03095-1. Archived from the original on 7 June 2011. Retrieved 31 December 2008.
  47. ^ 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.
  48. ^ a b c Tim Newcomb (7 July 2022). "Space Bubbles Could Be the Wild Idea We Need to Deflect Solar Radiation". Popular Mechanics. Archived from the original on 1 April 2023. Retrieved 23 May 2023.
  49. ^ a b Borgue, Olivia; Hein, Andreas M. (10 December 2022). "Transparent occulters: A nearly zero-radiation pressure sunshade to support climate change mitigation". Acta Astronautica. 203 (in press): 308–318. doi:10.1016/j.actaastro.2022.12.006. S2CID 254479656.
  50. ^ Oberth, Hermann (1984) [1923]. Die Rakete zu den Planetenräumen (in German). Michaels-Verlag Germany. pp. 87–88.
  51. ^ Oberth, Hermann (1970) [1929]. ways to spaceflight. NASA. Retrieved 21 December 2017 – via archiv.org.
  52. ^ Oberth, Hermann (1957). Menschen im Weltraum (in German). Econ Duesseldorf Germany. pp. 125–182.
  53. ^ Oberth, Hermann (1978). Der Weltraumspiegel (in German). Kriterion Bucharest.
  54. ^ J. T. Early (1989). "Space-Based Solar Shield To Offset Greenhouse Effect". Journal of the British Interplanetary Society. Vol. 42. pp. 567–569.
  55. ^ Teller, Edward; Hyde, Roderick; Wood, Lowell (1997). "Global Warming and Ice Ages: Prospects for Physics-Based Modulation of Global Change- See pages 10–14" (PDF). Lawrence Livermore National Laboratory. Archived from the original (PDF) on 27 January 2016. Retrieved 21 January 2015.
  56. ^ "Space Transportation Costs: Trends in Price Per Pound to Orbit ..." yumpu.com. Futron Corporation. 6 September 2002. Retrieved 3 January 2021.
  57. ^ Fuglesang, Christer; García de Herreros Miciano, María (5 June 2021). "Realistic sunshade system at L1 for global temperature control". Acta Astronautica. 186 (in press): 269–279. Bibcode:2021AcAau.186..269F. doi:10.1016/j.actaastro.2021.04.035.
  58. ^ "Space bubbles". MIT Senseable City Lab. Retrieved 24 May 2023.
  59. ^ Bromley, Benjamin C.; Khan, Sameer H.; Kenyon, Scott J. (8 February 2023). "Dust as a solar shield". PLOS Climate. 2 (2): e0000133. doi:10.1371/journal.pclm.0000133.
  60. ^ "Space dust as Earth's sun shield". Phys.org. 8 February 2023. Retrieved 2 July 2023.
  61. ^ a b 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. Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License
  62. ^ 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.
  63. ^ 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.
  64. ^ Arias, Paola A.; Bellouin, Nicolas; Coppola, Erika; Jones, Richard G.; et al. (2021). "Technical Summary" (PDF). Climate Change 2021: The Physical Science Basis.
  65. ^ 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.
  66. ^ 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. S2CID 225777399.
  67. ^ 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.
  68. ^ 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.
  69. ^ Intergovernmental Panel on Climate Change (IPCC) (22 June 2023). Climate Change 2022 – Impacts, Adaptation and Vulnerability: Working Group II Contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (1 ed.). Cambridge University Press. p. 2474. doi:10.1017/9781009325844.025. ISBN 978-1-009-32584-4.
  70. ^ Intergovernmental Panel on Climate Change (IPCC) (6 July 2023). 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. p. 629. doi:10.1017/9781009157896.006. ISBN 978-1-009-15789-6.
  71. ^ 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.
  72. ^ Rabitz, Florian (16 April 2019). "Governing the termination problem in solar radiation management". Environmental Politics. 28 (3): 502–522. Bibcode:2019EnvPo..28..502R. doi:10.1080/09644016.2018.1519879. ISSN 0964-4016. S2CID 158738431. Archived from the original on 11 June 2021. Retrieved 11 June 2021.
  73. ^ a b Intergovernmental Panel on Climate Change (IPCC) (22 June 2023). Climate Change 2022 – Impacts, Adaptation and Vulnerability: Working Group II Contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (1 ed.). Cambridge University Press. p. 19. doi:10.1017/9781009325844.001. ISBN 978-1-009-32584-4.
  74. ^ 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.
  75. ^ 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.
  76. ^ 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.
  77. ^ 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.
  78. ^ 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.
  79. ^ 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.
  80. ^ 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.
  81. ^ 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.
  82. ^ 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.
  83. ^ 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.
  84. ^ Smith, Wake; Bhattarai, Umang; MacMartin, Douglas G; Lee, Walker Raymond; Visioni, Daniele; Kravitz, Ben; Rice, Christian V Rice (15 September 2022). "A subpolar-focused stratospheric aerosol injection deployment scenario". Environmental Research Communications. 4 (9): 095009. Bibcode:2022ERCom...4i5009S. doi:10.1088/2515-7620/ac8cd3.
  85. ^ Trisos, Christopher H.; Amatulli, Giuseppe; Gurevitch, Jessica; Robock, Alan; Xia, Lili; Zambri, Brian (22 January 2018). "Potentially dangerous consequences for biodiversity of solar geoengineering implementation and termination". Nature Ecology & Evolution. 2 (3): 475–482. Bibcode:2018NatEE...2..475T. doi:10.1038/s41559-017-0431-0. ISSN 2397-334X. PMID 29358608. S2CID 256707843.
  86. ^ 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.
  87. ^ 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.
  88. ^ Horton, Joshua (2011). "Geoengineering and the myth of unilateralism: pressures and prospects for international cooperation". Stanford J Law Sci Policy (2): 56–69.
  89. ^ Intergovernmental Panel on Climate Change (IPCC) (22 June 2023). Climate Change 2022 – Impacts, Adaptation and Vulnerability: Working Group II Contribution to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (1 ed.). Cambridge University Press. p. 2477. doi:10.1017/9781009325844.025. ISBN 978-1-009-32584-4.
  90. ^ Intergovernmental Panel on Climate Change (IPCC), ed. (17 August 2023), "International Cooperation", Climate Change 2022 - Mitigation of Climate Change (1 ed.), Cambridge University Press, p. 1494, doi:10.1017/9781009157926.016, ISBN 978-1-009-15792-6, retrieved 24 June 2024
  91. ^ 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.
  92. ^ 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.
  93. ^ 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.
  94. ^ Millard-Ball, A. (2011). "The Tuvalu Syndrome". Climatic Change. 110 (3–4): 1047–1066. doi:10.1007/s10584-011-0102-0. S2CID 153990911.
  95. ^ Urpelainen, Johannes (10 February 2012). "Geoengineering and global warming: a strategic perspective". International Environmental Agreements: Politics, Law and Economics. 12 (4): 375–389. Bibcode:2012IEAPL..12..375U. doi:10.1007/s10784-012-9167-0. ISSN 1567-9764. S2CID 154422202.
  96. ^ 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. Bibcode:2013EnREc..56...85G. 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.
  97. ^ Moreno-Cruz, Juan B. (1 August 2015). "Mitigation and the geoengineering threat". Resource and Energy Economics. 41: 248–263. Bibcode:2015REEco..41..248M. doi:10.1016/j.reseneeco.2015.06.001. hdl:1853/44254.
  98. ^ "Home - call-for-balance.com". www.call-for-balance.com. Retrieved 9 March 2024.
  99. ^ "An open letter regarding research on reflecting sunlight to reduce the risks of climate change". climate intervention research letter. Retrieved 9 March 2024.
  100. ^ "Research to Inform Decisions about Climate Intervention". www.wcrp-climate.org. Retrieved 9 March 2024.
  101. ^ "Report of the World Commission on the Ethics of Scientific Knowledge and Technology (COMEST) on the ethics of climate engineering". unesdoc.unesco.org. Retrieved 9 March 2024.
  102. ^ "Position statement on climate intervention". AGU. Retrieved 9 March 2024.
  103. ^ Climate Science Special Report (Report). U.S. Global Change Research Program, Washington, DC. pp. 1–470.
  104. ^ "Reflecting Sunlight to Reduce Climate Risk: Priorities for Research and International Cooperation". Council on Foreign Relations. Retrieved 10 March 2024.
  105. ^ "Climate Change: Have We Lost the Battle?". www.imeche.org. Retrieved 9 March 2024.
  106. ^ Reekie, Tristan; Howard, Will (April 2012). "Geoengineering" (PDF). Retrieved 9 March 2024.
  107. ^ Brom, F. (2013). Riphagen, M (ed.). Klimaatengineering: hype, hoop of wanhoop?. Rathenau Instituut. ISBN 978-90-77364-51-2.
  108. ^ a b Julia Simon. "Startups want to cool Earth by reflecting sunlight. There are few rules and big risks". NPR. Retrieved 11 June 2024. In the past year, the conversation around solar geoengineering as a climate solution has become more serious, says David Keith ... Suddenly we're getting conversations with senior political leaders and senior people in the environmental world who are starting to think about this and engage with it seriously in a way that just wasn't happening five years ago,
  109. ^ a b "About". The Degrees Initiative. Retrieved 10 October 2023.
  110. ^ Chalmin, Anja. "Global Southwashing: How The Degrees Initiative is imposing its solar geoengineering agenda onto climate research in the Global South - Geoengineering Monitor". www.geoengineeringmonitor.org. Retrieved 18 December 2024.
  111. ^ a b "About". SilverLining. Retrieved 19 December 2024.
  112. ^ "SilverLining Announces $20.5 Million in Funding to Advance its Governance and Equity Initiatives on Near-Term Climate Risk and Climate Intervention". SilverLining. Retrieved 18 December 2024.
  113. ^ "About". DSG. Retrieved 10 March 2024.
  114. ^ "C2G Mission". C2G. Retrieved 10 March 2024.
  115. ^ a b "Reasons to Oppose Geoengineering - Geoengineering Monitor". www.geoengineeringmonitor.org. Retrieved 19 December 2024.
  116. ^ "Fuel to the Fire: How Geoengineering Threatens to Entrench Fossil Fuels and Accelerate the Climate Crisis (Feb 2019)". Center for International Environmental Law. Retrieved 9 March 2024.
  117. ^ 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.
  118. ^ 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.
  119. ^ "CAN Position: Solar Radiation Modification (SRM), September 2019". Climate Action Network. Retrieved 9 June 2024.
  120. ^ "Climate & Geoengineering | ETC Group". www.etcgroup.org. Retrieved 10 March 2024.
  121. ^ "Geoengineering | Heinrich Böll Stiftung". www.boell.de. Retrieved 10 March 2024.
  122. ^ "Geoengineering". Center for International Environmental Law. Retrieved 10 March 2024.
  123. ^ "What is Geoengineering Monitor? - Geoengineering Monitor". www.geoengineeringmonitor.org. Retrieved 18 December 2024.
  124. ^ 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.
  125. ^ "Open letter requesting cancellation of plans for geoengineering related test flights in Kiruna". Sámiráđđi (in Norwegian). 2 March 2021. Archived from the original on 19 July 2021. Retrieved 19 July 2021.
  126. ^ Flavelle, Christopher (28 November 2024). "The U.S. Is Building an Early Warning System to Detect Geoengineering". The New York Times. Archived from the original on 2 December 2024.
  127. ^ "Commission". Overshoot Commission. Retrieved 28 October 2024.
  128. ^ "Reducing the Risks of Climate Overshoot". Overshoot Commission. 2023. Retrieved 11 March 2024.
  129. ^ "Solar Geoengineering Non-Use Agreement". Solar Geoengineering Non-Use Agreement. Retrieved 14 March 2024.
  130. ^ "Open Letter". Solar Geoengineering Non-Use Agreement. Retrieved 14 March 2024.
  131. ^ "CAN Position: Solar Radiation Modification (SRM), September 2019". Climate Action Network. Retrieved 10 March 2024.
  132. ^ "Funding for Solar Geoengineering from 2008 to 2018". geoengineering.environment.harvard.edu. 13 November 2018. Archived from the original on 6 June 2021. Retrieved 6 June 2021.
  133. ^ 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.
  134. ^ "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.
  135. ^ Surprise, Kevin; Sapinski, Jp (2023). "Whose climate intervention? Solar geoengineering, fractions of capital, and hegemonic strategy". Capital & Class. 47 (4): 539–564. doi:10.1177/03098168221114386. ISSN 0309-8168.
  136. ^ "UK government's view on greenhouse gas removal technologies and solar radiation management". GOV.UK. Retrieved 9 March 2024.
  137. ^ a b Bundesumweltministeriums (6 December 2023). "Klimaaußenpolitik-Strategie der Bundesregierung (KAP)- BMUV - Download". bmuv.de (in German). Retrieved 9 March 2024.
  138. ^ "Geoengineering". geoengineering.environment.harvard.edu. Archived from the original on 6 June 2021. Retrieved 7 June 2021.
  139. ^ Temple, James (1 July 2022). "The US government is developing a solar geoengineering research plan". MIT Technology Review. Retrieved 16 April 2022.
  140. ^ "Funding for Solar Geoengineering from 2008 to 2018". geoengineering.environment.harvard.edu. 13 November 2018. Retrieved 9 March 2024.
  141. ^ "Research to Inform Decisions about Climate Intervention". www.wcrp-climate.org. Retrieved 10 December 2024.
  142. ^ "Homepage". SRM360. Retrieved 10 December 2024.
  143. ^ "Governance and Funding". SRM360. Retrieved 10 December 2024.
  144. ^ "LAD Climate Fund: Clear-Eyed, Comprehensive Climate Strategy". LAD Climate Fund. Retrieved 10 December 2024.
  145. ^ "Advisory Group". SRM360. Retrieved 10 December 2024.
  146. ^ a b "About". Reflective. Retrieved 10 December 2024.
  147. ^ "Make Sunsets". makesunsets.com. Retrieved 9 March 2024.
  148. ^ "Cooling Credits: a cost-effective solution for climate change – Make Sunsets". makesunsets.com. Retrieved 16 October 2024.
  149. ^ a b Secretaría de Medio Ambiente y Recursos, Gobierno de México. "La experimentación con geoingeniería solar no será permitida en México". gob.mx (in Spanish). Retrieved 16 October 2024.
  150. ^ 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.
  151. ^ 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.
  152. ^ 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.
  153. ^ 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.
  154. ^ 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. Bibcode:2020Ecomm..14..641S. doi:10.1080/17524032.2019.1699137. ISSN 1752-4032. S2CID 212981798. Archived from the original on 11 June 2021. Retrieved 11 June 2021.
  155. ^ Baum, Chad M.; Fritz, Livia; Low, Sean; Sovacool, Benjamin K. (6 March 2024). "Public perceptions and support of climate intervention technologies across the Global North and Global South". Nature Communications. 15 (1): 2060. Bibcode:2024NatCo..15.2060B. doi:10.1038/s41467-024-46341-5. ISSN 2041-1723. PMC 10918186. PMID 38448460.
  156. ^ Orquiola, John (4 February 2021). "Snowpiercer Theory: The World Is Warming Because Of The Train". SCREEN RANT. Retrieved 13 March 2023.
  157. ^ Wehrstedt, Lisa (30 January 2021). "Snowpiercer season 2: Mr Wilford intentionally kicked off apocalypse – here's how". Express. Retrieved 13 March 2023.
  158. ^ Robinson, Kim Stanley (2021). The ministry for the future (First paperback ed.). New York, NY: Orbit. ISBN 978-0-316-30013-1.
  159. ^ Stephenson, Neal (2021). Termination shock : a novel. New York, NY: HarperCollins. ISBN 978-0-06-302807-4.