Hadean

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Hadean

 

Artist's depiction of a collision between two planetary bodies, similar to the hypothesized collision between Theia and Proto-Earth
Artist's illustration of Earth and the Moon towards the middle/end of the Hadean eon
Chronology
−4500 — – — – −4000 — – — – −3500 — – — – −3000 — – — – −2500 — – — – −2000 — – — – −1500 — – — – −1000 — – — – −500 — – — – 0 — Precambrian Hadean Archean Proterozoic Phaner- ozoic Eoarchean Paleo­archean Mesoarchean Neoarchean Paleo­proterozoic Meso­proterozoic Neo­proterozoic Paleozoic Mesozoic Cenozoic       Vertical axis scale: Millions of years ago

The Hadean (/heɪˈdiːən, ˈheɪdiən/ hay-DEE-ən, HAY-dee-ən) is the first and oldest of the four geologic eons of Earth's history, starting with the planet's formation about 4.6 Ga^[4][5] (estimated 4567.30 ± 0.16 Ma set by the age of the oldest solid material in the Solar System—protoplanetary disk dust particles—found as chondrules and calcium–aluminium-rich inclusions in some meteorites about 4.567 Ga),^[6][1] and ending 4.031 Ga, the age of the oldest known intact rock formations on Earth as recognized by the International Commission on Stratigraphy. The interplanetary collision that created the Moon occurred early in this eon. The Hadean eon was succeeded by the Archean eon, with the Late Heavy Bombardment hypothesized to have occurred at the Hadean-Archean boundary.

Hadean rocks are very rare, largely consisting of granular zircons from one locality (Jack Hills) in Western Australia. Hadean geophysical models remain controversial among geologists: plate tectonics and the growth of cratons into continents may have started in the Hadean, but there is still uncertainty.

Earth in the early Hadean had a very thick hydride-rich atmosphere whose composition likely resembled the solar nebula and the gas giants, with mostly water vapor, methane and ammonia. As the Earth's surface cooled, vaporized atmospheric water condensed into liquid water and eventually a superocean covering nearly all of the planet was formed, turning Earth into an ocean planet. Volcanic outgassing and asteroid bombardments eventually altered the Hadean atmosphere into the nitrogen- and carbon dioxide-rich, weakly reducing Paleoarchean atmosphere.

Etymology

The eon's name "Hadean" comes from Hades, the Greek god of the underworld, referring to the hellish conditions then prevailing on early Earth: the planet had just been formed from recent accretion, and its surface is thought to have been molten lava.

The term was coined by American geologist Preston Cloud, originally to label the period before the earliest known rocks on Earth. W. B. Harland later coined an almost synonymous term, the Priscoan period, from priscus, a Latin word for 'ancient'. Other, older texts refer to the eon as the Pre-Archean.

Rock dating

Further information: Oldest dated rocks

Prior to the 1980s and the discovery of Hadean lithic fragments, scientific narratives of the early Earth explanations were almost entirely in the hands of geodynamic modelers.

Backscatter electron micrograph of detrital zircons from the Hadean (4.404 ± 0.008 Ga) metasediments of the Jack Hills, Narryer Gneiss terrane, Western Australia

In the last decades of the 20th century, geologists identified a few Hadean rocks from western Greenland, northwestern Canada, and Western Australia. In 2015, traces of carbon minerals interpreted as "remains of biotic life" were found in 4.1-billion-year-old rocks in Western Australia.

The oldest dated zircon crystals, enclosed in a metamorphosed sandstone conglomerate in the Jack Hills of the Narryer Gneiss terrane of Western Australia, date to 4.404 ± 0.008 Ga. This zircon is a slight outlier, with the oldest consistently dated zircon falling closer to 4.35 Ga—around 200 million years after the hypothesized time of Earth's formation.

In many other areas, xenocryst (or relict) Hadean zircons enclosed in older rocks indicate that younger rocks have formed on older terranes and have incorporated some of the older material. One example occurs in the Guiana shield from the Iwokrama Formation of southern Guyana where zircon cores have been dated at 4.22 Ga.

Atmosphere

A sizable quantity of water would have been in the material that formed Earth. Water molecules would have escaped Earth's gravity more easily when the planet was less massive during its formation. Photodissociation by short-wave ultraviolet in sunlight could split surface water molecules into oxygen and hydrogen, the former of which would readily react to form compounds in the then-reducing atmosphere, while the latter (along with the similarly light helium) would be expected to continually leave the atmosphere (as it does to the present day) due to atmospheric escape.

Part of the ancient planet is theorized to have been disrupted by the impact that created the Moon, which should have caused the melting of one or two large regions of Earth. Earth's present composition suggests that there was not complete remelting as it is difficult to completely melt and mix huge rock masses. However, a fair fraction of material should have been vaporized by this impact. The material would have condensed within 2,000 years. The initial magma ocean solidified within 5 million years, leaving behind hot volatiles which probably resulted in a heavy CO
₂ atmosphere with hydrogen and water vapor. The initial heavy atmosphere had a surface temperature of 230 °C (446 °F) and an atmospheric pressure of above 27 standard atmospheres.

Oceans

Hadean and Archean zircons with evaluation of δ¹⁸O

Studies of zircons have found that liquid water may have existed between 4.0 and 4.4 Ga, very soon after the formation of Earth. Liquid water oceans existed despite the high surface temperature, because at an atmospheric pressure of 27 atmospheres, water remains liquid.

The most likely source of the water in the Hadean ocean was outgassing from the Earth's mantle. Bombardment origin of a substantial amount of water is unlikely, due to the incompatibility of isotope fractions between the Earth and comets.

Asteroid impacts during the Hadean and into the Archean would have periodically disrupted the ocean. The geological record from 3.2 Ga contains evidence of multiple impacts of objects up to 100 kilometres (62 mi) in diameter. Each such impact would have boiled off up to 100 metres (330 ft) of a global ocean, and temporarily raised the atmospheric temperature to 500 °C (932 °F). However, the frequency of meteorite impacts is still under study: the Earth may have gone through long periods when liquid oceans and life were possible.

The liquid water would absorb the carbon dioxide in the early atmosphere; this would not be enough by itself to substantially reduce the amount of CO
₂.

Plate tectonics

Evolution of continental crust and ocean depths (from Korenaga, 2021)

A 2008 study of zircons found that Australian Hadean rock contains minerals pointing to the existence of plate tectonics as early as 4 Ga (approximately 600 million years after Earth's formation). However, some geologists suggest that the zircons could have been formed by meteorite impacts. The direct evidence of Hadean geology from zircons is limited, because the zircons are largely gathered in one locality in Australia. Geophysical models are underconstrained, but can paint a general picture of the state of Earth in the Hadean.

Mantle convection in the Hadean was likely vigorous, due to lower viscosity. The lower viscosity was due to the high levels of radiogenic heat and the fact that water in the mantle had not yet fully outgassed. Whether the vigorous convection led to plate tectonics in the Hadean or was confined under a rigid lid is still a matter of debate. The presence of Hadean oceans is thought to have triggered plate tectonics.

Subduction due to plate tectonics would have removed carbonate from the early oceans, contributing to the removal of the CO
₂-rich early atmosphere. Removal of this early atmosphere is evidence of Hadean plate tectonics.

If plate tectonics occurred in the Hadean, it would have formed continental crust. Different models predict different amounts of continental crust during the Hadean. The work of Dhiume et al. predicts that by the end of the Hadean, the continental crust had only 25% of today's area. The models of Korenaga, et al. predict that the continental crust grew to present-day volume sometime between 4.2 and 4.0 Ga.

Continents

The amount of exposed land in the Hadean is only loosely dependent on the amount of continental crust: it also depends on the ocean level. In models where plate tectonics started in the Archean, Earth has a global ocean in the Hadean. The high heat of the mantle may have made it difficult to support high elevations in the Hadean. If continents did form in the Hadean, their growth competed with outgassing of water from the mantle. Continents may have appeared in the mid-Hadean, and then disappeared under a thick ocean by the end of the Hadean. The limited amount of land has implications for the origin of life.

Possible life

Abundant Hadean-like geothermal microenvironments were shown by Salditt et al. to have the potential to support the synthesis and replication of RNA and thus possibly the evolution of a primitive life form. Porous rock systems comprising heated air-water interfaces were shown to allow ribozyme-catalyzed RNA replication of sense and antisense strands followed by subsequent strand dissociation, thus enabling combined synthesis, release and folding of active ribozymes. A study published in 2024 inferred the last common ancestor of all current life to have emerged during the Hadean, between 4.09 and 4.33 Ga.

Although the early part of the Late Heavy Bombardment happened during the Hadean, the impacts were frequent only on a cosmic scale, with thousands or even millions of years between each event. As Earth already had oceans, life would have been possible, but vulnerable to extinction events caused by those impacts. The risk would not be on the frequency, but on the size of the impactor, and remains on the Moon suggest impactors bigger than the Chicxulub impactor that caused the extinction of dinosaurs.

Carbonate–silicate cycle

From Wikipedia, the free encyclopedia

Not to be confused with Carbon cycle.

This figure describes the geological aspects and processes of the carbonate silicate cycle, within the long-term carbon cycle.

The carbonate–silicate geochemical cycle, also known as the inorganic carbon cycle, describes the long-term transformation of silicate rocks to carbonate rocks by weathering and sedimentation, and the transformation of carbonate rocks back into silicate rocks by metamorphism and volcanism. Carbon dioxide is removed from the atmosphere during burial of weathered minerals and returned to the atmosphere through volcanism. On million-year time scales, the carbonate-silicate cycle is a key factor in controlling Earth's climate because it regulates carbon dioxide levels and therefore global temperature.

The rate of weathering is sensitive to factors that change how much land is exposed. These factors include sea level, topography, lithology, and vegetation changes. Furthermore, these geomorphic and chemical changes have worked in tandem with solar forcing, whether due to orbital changes or stellar evolution, to determine the global surface temperature. Additionally, the carbonate-silicate cycle has been considered a possible solution to the faint young Sun paradox.

Overview of the cycle

This schematic shows the relationship between the different physical and chemical processes that make up the carbonate-silicate cycle.

The carbonate-silicate cycle is the primary control on carbon dioxide levels over long timescales. It can be seen as a branch of the carbon cycle, which also includes the organic carbon cycle, in which biological processes convert carbon dioxide and water into organic matter and oxygen via photosynthesis.

Physical and chemical processes

Microscopic shells of Foraminifera found in sediment cores may be used to determine past climate conditions including ocean temperatures and aspects of atmospheric chemistry.

The inorganic cycle begins with the production of carbonic acid (H₂CO₃) from rainwater and gaseous carbon dioxide. Due to this process, normal rain has a pH of around 5.6. Carbonic acid is a weak acid, but over long timescales, it can dissolve silicate rocks (as well as carbonate rocks). Most of the Earth's crust (and mantle) is composed of silicates. These substances break down into dissolved ions as a result. For example, calcium silicate (CaSiO₃), or wollastonite, reacts with carbon dioxide and water to yield a calcium ion, Ca²⁺, a bicarbonate ion, HCO₃⁻, and dissolved silica. This reaction structure is representative of general silicate weathering of calcium silicate minerals. The chemical pathway is as follows:

${\displaystyle 2{\text{CO}}_2^{}+{\text{H}}_2^{}\text{O}+{\text{CaSiO}}_3^{}⟶{\text{Ca}}^{2+}+2{\text{HCO}}_3^{-}+{\text{SiO}}_2^{}}$

River runoff carries these products to the ocean, where marine calcifying organisms use Ca²⁺ and HCO₃⁻ to build their shells and skeletons, a process called carbonate precipitation:

${\displaystyle {\text{Ca}}^{2+}+2{\text{HCO}}_3^{-}⟶{\text{CaCO}}_3^{}+{\text{CO}}_2^{}+{\text{H}}_2^{}\text{O}}$

Two molecules of CO₂ are required for silicate rock weathering; marine calcification releases one molecule back to the atmosphere. The calcium carbonate (CaCO₃) contained in shells and skeletons sinks after the marine organism dies and is deposited on the ocean floor.

The final stage of the process involves the movement of the seafloor. At subduction zones, the carbonate sediments are buried and forced back into the mantle. Some carbonate may be carried deep into the mantle where high pressure and temperature conditions allow it to combine metamorphically with SiO₂ to form CaSiO₃ and CO₂, which is released from the interior into the atmosphere via volcanism, thermal vents in the ocean, or soda springs, which are natural springs that contain carbon dioxide gas or soda water:

${\displaystyle {\text{CaCO}}_3^{}+{\text{SiO}}_2^{}⟶{\text{CaSiO}}_3^{}+{\text{CO}}_2^{}}$

This final step returns the second CO₂ molecule to the atmosphere and closes the inorganic carbon budget. 99.6% of all carbon on Earth (equating to roughly 10⁸ billion tons of carbon) is sequestered in the longterm rock reservoir. And essentially all carbon has spent time in the form of carbonate. By contrast, only 0.002% of carbon exists in the biosphere.

Feedbacks

Changes to the surface of the planet, such as an absence of volcanoes or higher sea levels, which would reduce the amount of land surface exposed to weathering can change the rates at which different processes in this cycle take place. Over tens to hundreds of millions of years, carbon dioxide levels in the atmosphere may vary due to natural perturbations in the cycle but even more generally, it serves as a critical negative feedback loop between carbon dioxide levels and climate changes. For example, if CO₂ builds up in the atmosphere, the greenhouse effect will serve to increase the surface temperature, which will in turn increase the rate of rainfall and silicate weathering, which will remove carbon from the atmosphere. In this way, over long timescales, the carbonate-silicate cycle has a stabilizing effect on the Earth's climate, which is why it has been called the Earth's thermostat.

Changes through Earth history

Aspects of the carbonate-silicate cycle have changed through Earth history as a result of biological evolution and tectonic changes. Generally, the formation of carbonates has outpaced that of silicates, effectively removing carbon dioxide from the atmosphere. The advent of carbonate biomineralization near the Precambrian-Cambrian boundary would have allowed more efficient removal of weathering products from the ocean. Biological processes in soils can significantly increase weathering rates. Plants produce organic acids that increase weathering. These acids are secreted by root and mycorrhizal fungi, as well as microbial plant decay. Root respiration and oxidation of organic soil matter also produce carbon dioxide, which is converted to carbonic acid, which increases weathering.

Tectonics can induce changes in the carbonate-silicate cycle. For example, the uplift of major mountain ranges, such as Himalayas and the Andes, is thought to have initiated the Late Cenozoic Ice Age due to increased rates of silicate weathering and draw down of carbon dioxide. Seafloor weather is linked both to solar luminosity and carbon dioxide concentration. However, it presented a challenge to modelers who have tried to relate the rate of outgassing and subduction to the related rates of seafloor change. Proper, uncomplicated proxy data is difficult to attain for such questions. For example, sediment cores, from which scientists can deduce past sea levels, are not ideal because sea levels change as a result of more than just seafloor adjustment. Recent modeling studies have investigated the role of seafloor weathering on the early evolution of life, showing that relatively fast seafloor creation rates worked to draw down carbon dioxide levels to a moderate extent.

Observations of so-called deep time indicate that Earth has a relatively insensitive rock weathering feedback, allowing for large temperature swings. With about twice as much carbon dioxide in the atmosphere, paleoclimate records show that global temperatures reached up to 5 to 6 °C higher than current temperatures. However, other factors such as changes in orbital/solar forcing contribute to global temperature change in the paleo-record.

Human emissions of CO₂ have been steadily increasing in a very short amount of time. Excess carbon in the atmosphere that is dissolved in seawater can alter the rates of carbonate-silicate cycle. Dissolved CO₂ may react with water to form bicarbonate ions, HCO₃⁻, and hydrogen ions, H⁺. These hydrogen ions quickly react with carbonate, CO₃^2- to produce more bicarbonate ions and reduce the available carbonate ions, which presents an obstacle to the carbon carbonate precipitation process. Put differently, 30% of excess carbon emitted into the atmosphere is absorbed by the oceans. Higher concentrations of carbon dioxide in the oceans work to push the carbonate precipitation process in the opposite direction (to the left), producing less CaCO₃. This process, which harms shell-building organisms, is called ocean acidification.

The cycle on other planets

One should not assume that a carbonate-silicate cycle would appear on all terrestrial planets. To begin, the carbonate-silicate cycle requires the presence of a water cycle. It therefore breaks down at the inner edge of the Solar System's habitable zone. Even if a planet starts out with liquid water on the surface, if it becomes too warm, it will undergo a runaway greenhouse, losing surface water. Without the requisite rainwater, no weathering will occur to produce carbonic acid from gaseous CO₂. Furthermore, at the outer edge, CO₂ may condense, consequently reducing the greenhouse effect and reducing the surface temperature. As a result, the atmosphere would collapse into polar caps.

Mars is such a planet. Located at the edge of the solar system's habitable zone, its surface is too cold for liquid water to form without a greenhouse effect. With its thin atmosphere, Mars' mean surface temperature is 210 K (−63 °C). In attempting to explain topographical features resembling fluvial channels, despite seemingly insufficient incoming solar radiation, some have suggested that a cycle similar to Earth's carbonate-silicate cycle could have existed – similar to a retreat from Snowball Earth periods. It has been shown using modeling studies that gaseous CO₂ and H₂O acting as greenhouse gases could not have kept Mars warm during its early history when the Sun was fainter because CO₂ would condense out into clouds. Even though CO₂ clouds do not reflect in the same way that water clouds do on Earth, it could not have had much of a carbonate-silicate cycle in the past.

By contrast, Venus is located at the inner edge of the habitable zone and has a mean surface temperature of 737 K (464 °C). After losing its water by photodissociation and hydrogen escape, Venus stopped removing carbon dioxide from its atmosphere, and began instead to build it up, and experience a runaway greenhouse effect.

On tidally locked exoplanets, the location of the substellar point will dictate the release of carbon dioxide from the lithosphere.

Disinformation

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Disinformation 

Disinformation is false or misleading information deliberately spread to deceive people, or to secure economic or political gain and which may cause public harm. Disinformation is an orchestrated adversarial activity in which actors employ strategic deceptions and media manipulation tactics to advance political, military, or commercial goals. Disinformation is implemented through coordinated campaigns that "weaponize multiple rhetorical strategies and forms of knowing—including not only falsehoods but also truths, half-truths, and value judgements—to exploit and amplify culture wars and other identity-driven controversies."

In contrast, misinformation refers to inaccuracies that stem from inadvertent error. Misinformation can be used to create disinformation when known misinformation is purposefully and intentionally disseminated. "Fake news" has sometimes been categorized as a type of disinformation, although scholars distinguish between the two concepts. Some researchers have cautioned against using the term in academic writing have because of its lack of precision and its contested use in public and political discourse regarding news coverage or information. Others note that it continues to be used both in reference to demonstrably false or misleading information and more broadly in political communication, where its meaning and implications remain debated.

Etymology

The Etymology of Disinformation by H. Newman as published in The Journal of Information Warfare in 2021. Elements of the word disinformation have their origins in Proto-Indo-European language family. The Latin 'dis' and 'in' and can both be considered to have Proto-Indo-European roots, 'forma' is considerably more obscure. The green box in the figure highlights the origin 'forma' is uncertain, however, it may have its roots in the Aristotelian concept of μορφή (morphe) where something becomes a 'thing' when it has 'form' or substance.

The English word disinformation comes from the application of the Latin prefix dis- to information making the meaning "reversal or removal of information". The rarely used word had appeared with this usage in print at least as far back as 1887. Some consider it a loan translation of the Russian дезинформация, transliterated as dezinformatsiya, apparently derived from the title of a KGB black propaganda department. Soviet planners in the 1950s defined disinformation as "dissemination (in the press, on the radio, etc.) of false reports intended to mislead public opinion."

Disinformation first made an appearance in dictionaries in 1985, specifically, Webster's New College Dictionary and the American Heritage Dictionary. In 1986, the term disinformation was not defined in Webster's New World Thesaurus or New Encyclopædia Britannica. After the Soviet term became widely known in the 1980s, native speakers of English broadened the term as "any government communication (either overt or covert) containing intentionally false and misleading material, often combined selectively with true information, which seeks to mislead and manipulate either elites or a mass audience."

By 1990, use of the term disinformation had fully established itself in the English language within the lexicon of politics. By 2001, the term disinformation had come to be known as simply a more civil phrase for saying someone was lying. Stanley B. Cunningham wrote in his 2002 book The Idea of Propaganda that disinformation had become pervasively used as a synonym for propaganda.

Operationalization

The Shorenstein Center at Harvard University defines disinformation research as an academic field that studies "the spread and impacts of misinformation, disinformation, and media manipulation", including "how it spreads through online and offline channels, and why people are susceptible to believing bad information, and successful strategies for mitigating its impact". According to a 2023 research article published in New Media & Society, disinformation circulates on social media through deception campaigns implemented in multiple ways including: astroturfing, conspiracy theories, clickbait, culture wars, echo chambers, hoaxes, fake news, propaganda, pseudoscience, and rumors.

Glossary of key terms related to disinformation and misinformation
Term	Description	Term	Description
Astroturfing	A centrally coordinated campaign that mimics grassroots activism by making participants pretend to be ordinary citizens	Fake news	Genre: The deliberate creation of pseudo-journalism Label: The instrumentalization of the term to delegitimize news media
Conspiracy theories	Rebuttals of official accounts that propose alternative explanations in which individuals or groups act in secret	Greenwashing	Deceptive communication makes people believe that a company is environmentally responsible when it is not
Clickbait	The deliberate use of misleading headlines and thumbnails to increase online traffic for profit or popularity	Propaganda	Organized mass communication, on a hidden agenda, and with a mission to conform belief and action by circumventing individual reasoning
Culture wars	A phenomenon in which multiple groups of people, who hold entrenched values, attempt to steer public policy contentiously	Pseudoscience	Accounts that claim the explanatory power of science, borrow its language and legitimacy but diverge substantially from its quality criteria
Doxxing	A form of online harassment that breaches privacy boundaries by releasing information intending physical and online harm to a target	Rumors	Unsubstantiated news stories that circulate while not corroborated or validated
Echo chamber	An epistemic environment in which participants encounter beliefs and opinions that coincide with their own	Trolling	Networked groups of digital influencers that operate 'click armies' designed to mobilize public sentiment
Hoax	News in which false facts are presented as legitimate	Urban legends	Moral tales featuring durable stories of intruders incurring boundary transgressions and their dire consequences

In order to distinguish between similar terms, including misinformation and malinformation, scholars collectively agree on the definitions for each term as follows: (1) disinformation is the strategic dissemination of false information with the intention to cause public harm; (2) misinformation represents the unintentional spread of false information; and (3) malinformation is factual information disseminated with the intention to cause harm, these terms are abbreviated 'DMMI'.

In 2019, Camille François devised the "ABC" framework of understanding different modalities of online disinformation:

• Manipulative Actors, who "engage knowingly and with clear intent in viral deception campaigns" that are "covert, designed to obfuscate the identity and intent of the actor orchestrating them." Examples include personas such as Guccifer 2.0, Internet trolls, state media, and military operatives.
• Deceptive Behavior, which "encompasses the variety of techniques viral deception actors may use to enhance and exaggerate the reach, virality and impact of their campaigns." Examples include troll farms, Internet bots, astroturfing, and "paid engagement".
• Harmful Content, which includes health misinformation, manipulated media such as deepfakes, online harassment, violent extremism, hate speech or terrorism.

In 2020, the Brookings Institution proposed amending this framework to include Distribution, defined by the "technical protocols that enable, constrain, and shape user behavior in a virtual space". Similarly, the Carnegie Endowment for International Peace proposed adding Degree ("distribution of the content ... and the audiences it reaches") and Effect ("how much of a threat a given case poses").

Comparisons with propaganda

Whether and to what degree disinformation and propaganda overlap is subject to debate. Some (like U.S. Department of State) define propaganda as the use of non-rational arguments to either advance or undermine a political ideal, and use disinformation as an alternative name for undermining propaganda, while others consider them to be separate concepts altogether. One popular distinction holds that disinformation also describes politically motivated messaging designed explicitly to engender public cynicism, uncertainty, apathy, distrust, and paranoia, all of which disincentivize citizen engagement and mobilization for social or political change.

Practice

Disinformation is the label often given to foreign information manipulation and interference (FIMI). Studies on disinformation are often concerned with the content of activity whereas the broader concept of FIMI is more concerned with the "behaviour of an actor" that is described through the military doctrine concept of tactics, techniques, and procedures (TTPs).

Disinformation is primarily carried out by government intelligence agencies, but has also been used by non-governmental organizations and businesses. Front groups are a form of disinformation, as they mislead the public about their true objectives and who their controllers are. Most recently, disinformation has been deliberately spread through social media in the form of "fake news", disinformation masked as legitimate news articles and meant to mislead readers or viewers. Disinformation may include distribution of forged documents, manuscripts, and photographs, or spreading dangerous rumours and fabricated intelligence. Use of these tactics can lead to blowback, however, causing such unintended consequences such as defamation lawsuits or damage to the dis-informer's reputation.

Disinformation can spread with greater ease in situations where there is a lack of credible information on a topic, such as a crisis. The implications of this were seen after the 2024 Southport stabbings, where the spread of disinformation regarding the killer's background was fuelled by reporting restrictions, meaning that there were no facts to counter the disinformation. This then led to the 2024 United Kingdom riots.

Worldwide

Disinformation has been identified as a significant challenge, undermining public trust and the factual basis for public debate. Studies have found that false information often spreads faster and more widely online than accurate information. Empirical research has also links disinformation to political polarisation, democratic erosion, and regime resilience in authoritarian contexts.

Soviet disinformation

Former Romanian secret police senior official Ion Mihai Pacepa exposed disinformation history in his book Disinformation (2013).

Use of disinformation as a Soviet tactical weapon started in 1923, when it became a tactic used in the Soviet political warfare called active measures.

Russian disinformation

Russian disinformation campaigns have occurred in many countries. For example, disinformation campaigns led by Yevgeny V. Prigozhin, a Russian oligarch, have been reported in several African countries. Russia denies that it uses disinformation to influence public opinion. Often Russian campaigns aim to disrupt domestic politics within Europe and the United States in an attempt to weaken the West due to its long-standing commitment to fight back against "Western imperialism" and shift the balance of world power to Russia and its allies (the Second World during the Cold War era). According to the Voice of America, Russia seeks to promote American isolationism, border security concerns and racial tensions within the United States through its disinformation campaigns.

Chinese disinformation

Spamouflage (also known under the names Dragonbridge, Spamouflage Dragon, Storm 1376 and Taizi Flood) is an online propaganda and disinformation operation that has been using a network of social media accounts to make posts in favor of the Chinese Communist Party and government of the People's Republic of China and harass dissidents and journalists overseas since 2017. Beginning in the early 2020s, Spamouflage accounts also began making posts about American and Taiwanese politics. It is widely believed that the Chinese government, particularly the Ministry of Public Security, is behind the network. Spamouflage has increasingly used generative artificial intelligence for influence operations. The campaign has largely failed to receive views from real users, although it has attracted some organic engagement using new tactics.

American disinformation

How Disinformation Can Be Spread, explanation by U.S. Defense Department (2001)

The United States Intelligence Community appropriated use of the term disinformation in the 1950s from the Russian dezinformatsiya, and began to use similar strategies, starting during Cold War, and in conflict with other nations. The New York Times reported in 2000 that during the CIA's effort to substitute Mohammed Reza Pahlavi for then-Prime Minister of Iran Mohammad Mossadegh, the CIA placed fictitious stories in the local newspaper. Reuters documented how, subsequent to the 1979 Soviet Union invasion of Afghanistan during the Soviet–Afghan War, the CIA put false articles in newspapers of Islamic-majority countries, inaccurately stating that Soviet embassies had "invasion day celebrations". Reuters noted a former U.S. intelligence officer said they would attempt to gain the confidence of reporters and use them as secret agents, to affect a nation's politics by way of their local media.

In October 1986, the term gained increased currency in the U.S. when it was revealed that two months previously, the Reagan Administration had engaged in a disinformation campaign against then-leader of Libya Muammar Gaddafi. White House representative Larry Speakes said reports of a planned attack on Libya as first broken by The Wall Street Journal on August 25, 1986, were "authoritative", and other newspapers including The Washington Post then wrote articles saying this was factual. U.S. State Department representative Bernard Kalb resigned from his position in protest over the disinformation campaign, and said: "Faith in the word of America is the pulse beat of our democracy."

The executive branch of the Reagan administration kept watch on disinformation campaigns through three yearly publications by the Department of State: Active Measures: A Report on the Substance and Process of Anti-U.S. Disinformation and Propaganda Campaigns (1986); Report on Active Measures and Propaganda, 1986–87 (1987); and Report on Active Measures and Propaganda, 1987–88 (1989).

According to a report by Reuters, the United States ran a propaganda campaign to spread disinformation about the Sinovac Chinese COVID-19 vaccine, including using fake social media accounts to spread the disinformation that the Sinovac vaccine contained pork-derived ingredients and was therefore haram under Islamic law. Reuters said the ChinaAngVirus disinformation campaign was designed to "counter what it perceived as China's growing influence in the Philippines" and was prompted by the "[fear] that China's COVID diplomacy and propaganda could draw other Southeast Asian countries, such as Cambodia and Malaysia, closer to Beijing". The campaign was also described as "payback for Beijing's efforts to blame Washington for the pandemic". The campaign primarily targeted people in the Philippines and used a social media hashtag for "China is the virus" in Tagalog. The campaign ran from 2020 to mid-2021. The primary contractor for the U.S. military on the project was General Dynamics IT, which received $493 million for its role.

Since 2023, Republican members of the US Congress have attacked researchers who study disinformation as being against freedom of speech and as a euphemism for government censorship. On April 18, 2025, citing an Executive Order signed by Trump, the US National Science Foundation released a statement cancelling funding for disinformation research, saying that it does not fit with the NSF priorities, "including but not limited to those on diversity, equity, and inclusion (DEI) and misinformation/disinformation."

Disinformation in the 2016 United Kingdom European Union membership referendum

The 2016 United Kingdom European Union membership referendum saw figures from the Leave campaign spread disinformation on social media. Many of these arguments played on voters' emotions and attachments, such as the claim that the £350 million that the UK sent to the EU each week could be allocated to the NHS instead, which made them highly effective. Ofcom requires news broadcasters to remain neutral, yet this adherence to neutrality created false balance in the Brexit debate, causing broadcasters to inadvertedly promote disinformation.

Response

Responses from cultural leaders

Pope Francis condemned disinformation in a 2016 interview, after being made the subject of a fake news website during the 2016 U.S. election cycle which falsely claimed that he supported Donald Trump. He stated that the worst thing the news media could do was spread disinformation and said the act was a sin, comparing those who spread disinformation to individuals who engage in coprophilia.

Ethics in warfare

In a contribution to the 2014 book Military Ethics and Emerging Technologies, writers David Danks and Joseph H. Danks discuss the ethical implications in using disinformation as a tactic during information warfare. They note there has been a significant degree of philosophical debate over the issue as related to the ethics of war and use of the technique. The writers describe a position whereby the use of disinformation is occasionally allowed, but not in all situations. Typically the ethical test to consider is whether the disinformation was performed out of a motivation of good faith and acceptable according to the rules of war. By this test, the tactic during World War II of putting fake inflatable tanks in visible locations on the Pacific Islands in order to falsely present the impression that there were larger military forces present would be considered as ethically permissible. Conversely, disguising a munitions plant as a healthcare facility in order to avoid attack would be outside the bounds of acceptable use of disinformation during war.

Research

Main article: Disinformation research

Disinformation spreads through controversies.

Research related to disinformation studies is increasing as an applied area of inquiry. The call to formally classify disinformation as a cybersecurity threat is made by advocates due to its increase in social networking sites. Despite the proliferation of social media websites, Facebook and Twitter showed the most activity in terms of active disinformation campaigns. Techniques reported on included the use of bots to amplify hate speech, the illegal harvesting of data, and paid trolls to harass and threaten journalists.

Whereas disinformation research focuses primarily on how actors orchestrate deceptions on social media, primarily via fake news, new research investigates how people take what started as deceptions and circulate them as their personal views. As a result, research shows that disinformation can be conceptualized as a program that encourages engagement in oppositional fantasies (i.e., culture wars), through which disinformation circulates as rhetorical ammunition for never-ending arguments. As disinformation entangles with culture wars, identity-driven controversies constitute a vehicle through which disinformation disseminates on social media. This means that disinformation thrives, not despite raucous grudges but because of them. The reason is that controversies provide fertile ground for never-ending debates that solidify points of view.

Scholars have pointed out that disinformation is not only a foreign threat as domestic purveyors of disinformation are also leveraging traditional media outlets such as newspapers, radio stations, and television news media to disseminate false information. Current research suggests right-wing online political activists in the United States may be more likely to use disinformation as a strategy and tactic. The 2016 European Union referendum in the UK also saw British politicians supporting the Leave campaign spread disinformation on Twitter. The Conservative Party was also accused of spreading disinformation about the Labour Party in the lead-up to the 2019 General Election. Governments have responded with a wide range of policies to address concerns about the potential threats that disinformation poses to democracy, however, there is little agreement in elite policy discourse or academic literature as to what it means for disinformation to threaten democracy, and how different policies might help to counter its negative implications.

Consequences of exposure to disinformation online

There is a broad consensus amongst scholars that there is a high degree of disinformation, misinformation, and propaganda online; however, it is unclear to what extent such disinformation has on political attitudes in the public and, therefore, political outcomes. This conventional wisdom has come mostly from investigative journalists, with a particular rise during the 2016 U.S. election: some of the earliest work came from Craig Silverman at Buzzfeed News. Cass Sunstein supported this in #Republic, arguing that the internet would become rife with echo chambers and informational cascades of misinformation leading to a highly polarized and ill-informed society. Later studies have since proven the existence of echo chambers on social media.

Research after the 2016 US presidential election found: (1) for 14% of Americans social media was their "most important" source of election news; 2) known false news stories "favoring Trump were shared a total of 30 million times on Facebook, while those favoring Clinton were shared 8 million times"; 3) the average American adult saw fake news stories, "with just over half of those who recalled seeing them believing them"; and 4) people are more likely to "believe stories that favor their preferred candidate, especially if they have ideologically segregated social media networks." Correspondingly, whilst there is wide agreement that the digital spread and uptake of disinformation during the 2016 election was massive and very likely facilitated by foreign agents, there is an ongoing debate on whether all this had any actual effect on the election. For example, a double blind randomized-control experiment by researchers from the London School of Economics (LSE), found that exposure to online fake news about either Trump or Clinton had no significant effect on intentions to vote for those candidates. Researchers who examined the influence of Russian disinformation on Twitter during the 2016 US presidential campaign found that exposure to disinformation was (1) concentrated among a tiny group of users, (2) primarily among Republicans, and (3) eclipsed by exposure to legitimate political news media and politicians. Finally, they find "no evidence of a meaningful relationship between exposure to the Russian foreign influence campaign and changes in attitudes, polarization, or voting behavior." As such, despite its mass dissemination during the 2016 Presidential Elections, online fake news or disinformation probably did not cost Hillary Clinton the votes needed to secure the presidency.

Research on this topic remains inconclusive, for example, misinformation appears not to significantly change political knowledge of those exposed to it. There seems to be a higher level of diversity of news sources that users are exposed to on Facebook and Twitter than conventional wisdom would dictate, as well as a higher frequency of cross-spectrum discussion. Other evidence has found that disinformation campaigns rarely succeed in altering the foreign policies of the targeted states.

Research is also challenging because disinformation is meant to be difficult to detect and some social media companies have discouraged outside research efforts. For example, researchers found disinformation made "existing detection algorithms from traditional news media ineffective or not applicable...[because disinformation] is intentionally written to mislead readers...[and] users' social engagements with fake news produce data that is big, incomplete, unstructured, and noisy." Facebook, the largest social media company, has been criticized by analytical journalists and scholars for preventing outside research of disinformation.

Alternative perspectives and critiques

Researchers have criticized the framing of disinformation as being limited to technology platforms, removed from its wider political context and inaccurately implying that the media landscape was otherwise well-functioning. "The field possesses a simplistic understanding of the effects of media technologies; overemphasizes platforms and underemphasizes politics; focuses too much on the United States and Anglocentric analysis; has a shallow understanding of political culture and culture in general; lacks analysis of race, class, gender, and sexuality as well as status, inequality, social structure, and power; has a thin understanding of journalistic processes; and, has progressed more through the exigencies of grant funding than the development of theory and empirical findings."

Alternative perspectives have been proposed:

1. Moving beyond fact-checking and media literacy to study a pervasive phenomenon as something that involves more than news consumption.
2. Moving beyond technical solutions including AI-enhanced fact checking to understand the systemic basis of disinformation.
3. Develop a theory that goes beyond Americentrism to develop a global perspective, understand cultural imperialism and Third World dependency on Western news, and understand disinformation in the Global South.
4. Develop market-oriented disinformation research that examines the financial incentives and business models that nudge content creators and digital platforms to circulate disinformation online.
5. Include a multidisciplinary approach, involving history, political economy, ethnic studies, feminist studies, and science and technology studies.
6. Develop understandings of Gendered-based disinformation (GBD) defined as "the dissemination of false or misleading information attacking women (especially political leaders, journalists and public figures), basing the attack on their identity as women."

Strategies for spreading disinformation

Disinformation attack

Main article: Disinformation attack

The research literature on how disinformation spreads is growing. Studies show that disinformation spread in social media can be classified into two broad stages: seeding and echoing. "Seeding", when malicious actors strategically insert deceptions, like fake news, into a social media ecosystem, and "echoing" is when the audience disseminates disinformation argumentatively as their own opinions often by incorporating disinformation into a confrontational fantasy.

Internet manipulation

Separate from factual reporting, techniques such as rage baiting, outrage porn, etc. involve media broadcast of content designed to manipulate increased viewer engagement, often by provoking negative emotional responses aligned with political or other narratives.

Internet manipulation is the use of online digital technologies, including algorithms, social bots, and automated scripts, for commercial, social, military, or political purposes. Internet and social media manipulation are the prime vehicles for spreading disinformation due to the importance of digital platforms for media consumption and everyday communication. When employed for political purposes, internet manipulation may be used to steer public opinion, polarise citizens, circulate conspiracy theories, and silence political dissidents. Internet manipulation can also be done for profit, for instance, to harm corporate or political adversaries and improve brand reputation. Internet manipulation is sometimes also used to describe the selective enforcement of Internet censorship or selective violations of net neutrality.

Internet manipulation for propaganda purposes with the help of data analysis and internet bots in social media is called computational propaganda.

Studies show four main methods of seeding disinformation online:

1. Selective censorship
2. Manipulation of search rankings
3. Hacking and releasing
4. Directly sharing disinformation

Recently, concerns have been expressed that AI technology could enable groups of AI programs, known as 'AI swarms,' to autonomously coordinate to manipulate democratic discourse, by maintaining persistent fake identities and mimicking human social dynamics over extended periods of time.

Exploiting online advertising technologies

Disinformation is amplified online due to malpractice concerning online advertising, especially the machine-to-machine interactions of real-time bidding systems. Online advertising technologies have been used to amplify disinformation due to the financial incentives and monetization of user-generated content and fake news. The lax oversight over the online advertising market can be used to amplify disinformation, including the use of dark money used for political advertising.