The original 2023 PDF booklet of 54p is *Marine de Guglielmo Weber, et autres. (2023, Novembre). Géo-ingénierie solaire: enjeux géostratégiques et de défense. l’Observatoire Défense & Climat.* https://defenseclimat.fr/wp-content/uploads/2023/11/Note_5_Obs-DC_Geo-ingenierie_VF.pdf
Le mar. 10 sept. 2024 à 14:25, Geoengineering News < [email protected]> a écrit : > > https://www.politics-dz.com/opportunities-and-risks-solar-geoengineering-scenarios-for-climate-change-mitigation-by-2050/ > > *07 September 2024* > > With warnings of rising planetary temperatures and the international > community’s failure to implement preventative policies to combat climate > change, the importance of developing technological solutions like solar > geoengineering has increased. Solar geoengineering aims to reduce global > temperatures by modifying solar radiation (SRM) or by decreasing > atmospheric carbon dioxide through capture and storage in oceans or on land > (CDR). In the absence of a genuine commitment to reducing emissions, > scientists propose solar geoengineering as a last-ditch effort to tackle > global warming. > > In this context, a recent report by the French Defense and Climate > Observatory highlighted the developments in the widespread deployment of > solar geoengineering technologies in the coming decades, the associated > natural and human risks, key actors, and the role of major powers in this > field. The report also presented potential scenarios and recommendations > for deploying these technologies by 2050. > *Nature of Technologies and Risks:* > > Solar geoengineering, or solar radiation management (SRM), involves > techniques designed to reflect sunlight to cool the Earth through > large-scale, deliberate intervention in the Earth’s climate system to > mitigate the harmful effects of global warming. However, using these > techniques involves both human and natural risks. Several types of SRM > technologies are designed, including: > > *Local Solar Geoengineering:* Two local techniques have been developed: > marine cloud brightening (MCB) and cloud thinning (CCT). Marine cloud > brightening involves injecting tiny droplets into marine clouds to make > them brighter and more reflective by spraying sea salt into low marine > clouds. Brighter clouds help reduce the amount of solar radiation reaching > the Earth’s surface, thereby lowering atmospheric and ocean temperatures. > > *Planetary Solar Geoengineering:* This involves injecting aerosols into > the stratosphere (SAI) on a planetary scale. This method disperses > reflective particles via aircraft or balloons in the stratosphere, > targeting the release of sulfate particles to reduce the amount of sunlight > reaching the Earth and the heat trapped in the atmosphere. This approach > aims to create cooling conditions similar to those following major volcanic > eruptions. While this technique is the most studied for modifying radiative > balance, it is also the most controversial due to its planetary scope and > associated scientific uncertainties. > > *Space-Based Solar Geoengineering:* Some solar geoengineering projects > plan to deploy reflective devices (mirrors) in outer space to reflect about > 2% of sunlight. This technique is less advanced and less studied due to its > complexity and high costs, estimated in billions of dollars. Mirrors would > need to be launched by rocket and positioned about 1,500,000 kilometers > from Earth at the “Lagrange L1” point, where Earth’s gravity > counterbalances the Sun’s gravity, allowing objects to be stable in orbit. > > According to a 2023 United Nations report on solar geoengineering, the > mirrors would last about 20 years. Currently, there is only one space-based > geoengineering project, titled “Space Bubbles,” being carried out by a team > from MIT, aimed at dispersing some sunlight away from Earth. However, it > remains theoretical. > > There are several natural risks associated with the three solar > geoengineering techniques, including: persistent effects related to > increased carbon dioxide levels, reduced photosynthesis affecting humidity, > rainfall, and local oxygen concentrations (e.g., drought in South America, > increased tropical rainfall), ozone layer degradation, increased > hurricanes, and extreme climate changes with severe impacts on temperatures > and ecosystems due to solar radiation. > > Human risks include: reduced agricultural yields, decreased primary > productivity in the Amazon, slight increases in rainfall disruption in > Africa, health risks associated with temperature changes, declining air > quality, and loss of ecosystem services (e.g., decreased photosynthesis). > > > Additionally, there is a common risk known as “social and technical > lock-in,” where developed technologies become entrenched due to economic > and political interests, making it difficult to reverse their deployment > even if they prove ineffective or harmful, leading to what is known as > “terminal shock.” This risk is particularly relevant for space mirrors, > which might become targets in military conflicts, potentially causing an > immediate increase in global temperatures. This risk also applies to > geoengineering operations requiring ongoing chemical interventions. > *Network of Actors:* > > The actors in the field of solar geoengineering vary between major > countries, the scientific community, as well as the private sector, > international bodies, and non-governmental organizations. However, major > powers remain the most influential actors in the solar geoengineering > network. Key players include: > > *United States:* The country is the most advanced in solar > geoengineering, dominating the sector through several major projects (such > as Harvard, the University of California, Cornell). The Department of > Defense is significantly involved, and the private sector has increasingly > financed research, granting around $20 million from 2008 to 2018 for solar > geoengineering initiatives and projects. > > *China:* Active in solar geoengineering research, as evidenced by a > publicly funded Chinese research project from 2015 to 2019. This project > aims to study the climate impacts of solar geoengineering and explore > related governance issues. In August 2020, China conducted a local solar > geoengineering experiment on the Dagu Glacier in Sichuan to reduce glacier > melting during summer. > > *Russia:* Does not have a research program in solar geoengineering based > on available information. However, the former Soviet Union had laid the > groundwork for aerosol injection into the stratosphere, a proposal by > researcher Budyko in the late 1970s. Moscow’s official stance appears > supportive of solar geoengineering, as evidenced by its request to include > a section on it as a potential climate change solution in the 2013 > Intergovernmental Panel on Climate Change report and its acknowledgment of > ongoing developments in geoengineering techniques. > *Expected Scenarios:* > > Several scenarios are proposed for the future of solar geoengineering by > 2050: > > *Scenario One: Unilateral Deployment by the United States:* This scenario > assumes that by 2047, the global average temperature will rise by +2.5°C > compared to pre-industrial levels, with greenhouse gas emissions not > sufficiently reduced and the international community failing to meet Paris > Agreement goals. All countries will experience widespread natural disasters > annually, resulting in thousands of casualties and displaced people, > weakening the economic situation globally. In the U.S., political tensions > rise, and the country becomes the world’s second superpower after China, > starting from 2039. Additionally, drought and water scarcity severely > impact agriculture, making cotton and corn cultivation impossible, and > soybean and wheat yields drop by about 40% starting in 2025. > > In this context, public criticism of the U.S. government increases for not > adequately anticipating climate change impacts and delaying adaptation > efforts. Consequently, in 2047, the U.S. officially announces the > deployment of stratospheric aerosol injection, while it has not ratified > the 2035 Solar Geoengineering Convention that prohibits unilateral > technology deployment. This unilateral decision entrenches international > polarization. With the UN and Security Council failing to resolve the > crisis, Russia and China, along with a few partners, launch a diplomatic > campaign condemning the “selfish” actions of the U.S., threatening military > intervention, and initiating discussions within the alliance about > counter-solar geoengineering operations. > > *Scenario Two: China and the “ArcticX” Project:* This scenario posits > that by 2050, global warming will reach +2.6°C compared to pre-industrial > times. This will lead to the collapse of the Greenland ice sheet, the > complete disappearance of winter ice in the Barents Sea, and the melting of > summer ice in the Arctic, causing a two-meter rise in average sea levels, > submerging thousands of homes, and leaving entire communities without > habitable land. Biodiversity will also face consecutive extinctions, with > thousands of plant and animal species disappearing since 2020. > Additionally, conflicts over water and food resources, as well as social > and environmental conflicts, will intensify. > > In this context, an alliance of countries will form to deploy solar > geoengineering technologies, with the U.S., China, and India leading, > aiming to mitigate climate change impacts and calm rising social > disturbances. After several proposals for deployment are rejected by the > UN, China proposes a regional solar geoengineering initiative to protect > the Arctic, announcing the “ArcticX” project in 2050, which aims to enhance > the reflectivity of marine clouds over the Arctic. > > This regional deployment receives support from all allied countries and > most regional nations (such as Canada, Norway, Denmark, and Iceland), > interested in protecting the poles. However, it faces opposition from > Moscow, as melting ice caps in Greenland and the Barents Sea would allow > Russia to use the Arctic as a commercial shipping route, rich in oil, > natural gas, and minerals, and crucial fish resources. Consequently, Russia > threatens to militarily attack the ships deployed by China. > > *Scenario Three: Solar Geoengineering as a New Consumer Commodity:* In > the first half of the 21st century, the Amazon rainforest gradually > transforms into savanna, releasing increasing amounts of carbon dioxide > into the atmosphere, surpassing an irreparable tipping point, resulting in > a rise in the global average temperature to +3°C by 2037 compared to > pre-industrial levels. Agricultural losses will affect 40% of global > production. Consequently, technological advancements in carbon extraction > from the atmosphere will face commercial and political failure due to > ineffective technologies and social and environmental conflicts. > > In this context, several countries (including the U.S., the U.K., Gulf > States, Russia, and Maghreb countries), supported by oil lobby groups, will > move towards deploying solar geoengineering. Europe will be divided, with > Sweden, Norway, and Spain opposing any solar geoengineering deployment and > implementing an emergency mitigation plan, while countries like France, > Germany, and Italy will emphasize the need for urgent cooling measures. In > 2037, oil lobby groups, backed by the U.S. and Gulf States, will develop a > strategy to promote solar geoengineering to individual consumers, creating > a new commercial market by promoting a new form of individual climate > commitment. Meanwhile, several G77 countries, led by China, will strongly > oppose these moves. > > In conclusion, the French Ministry of Defense recommended integrating > solar geoengineering as a political, geostrategic, and military tool, > enhancing information exchange in this field, particularly through raising > the issue in strategic bilateral dialogues, strengthening partnerships with > atmospheric science research institutes (such as MétéoFrance), and > integrating research on climate change impacts on natural systems and > potential effects of solar geoengineering. The ministry also recommended > establishing a scientific, technological, and geostrategic monitoring body > to oversee the development of solar geoengineering projects and anticipate > the ability of various actors to maintain technological leadership enabling > unilateral large-scale deployment. > > *Source: Politics_DZ* > > -- > You received this message because you are subscribed to the Google Groups > "geoengineering" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/geoengineering/CAHJsh98o5Admqz7OkNpXEewRnFkDO%2BEb%2BadycnLwvwpHV4oBmw%40mail.gmail.com > <https://groups.google.com/d/msgid/geoengineering/CAHJsh98o5Admqz7OkNpXEewRnFkDO%2BEb%2BadycnLwvwpHV4oBmw%40mail.gmail.com?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "geoengineering" group. 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