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Italo Calvino

Italo Calvino (, also, ; 15 October 1923 – 19 September 1985) was an Italian writer and journalist. His best-known works include the Our Ancestors trilogy (1952–1959), the Cosmicomics collection of short stories (1965), and the novels Invisible Cities (1972) and If on a winter's night a traveler (1979).

Admired in Britain, Australia and the United States, Calvino was the most translated contemporary Italian writer at the time of his death. He is buried in the garden cemetery of Castiglione della Pescaia in Tuscany.

Parents
Italo Calvino was born in Santiago de las Vegas, a suburb of Havana, Cuba, in 1923. His father, Mario, was a tropical agronomist and botanist who also taught agriculture and floriculture. Born 47 years earlier in Sanremo, Italy, Mario Calvino had emigrated to Mexico in 1909 where he took up an important position with the Ministry of Agriculture. In an autobiographical essay, Italo Calvino explained that his father "had been in his youth an anarchist, a follower of Kropotkin and then a Socialist Reformist". In 1917, Mario left for Cuba to conduct scientific experiments, after living through the Mexican Revolution.

Calvino's mother, Giuliana Luigia Evelina "Eva" Mameli, was a botanist and university professor. A native of Sassari in Sardinia and 11 years younger than her husband, she married while still a junior lecturer at Pavia University. Born into a secular family, Eva was a pacifist educated in the "religion of civic duty and science". Eva gave Calvino his unusual first name to remind him of his Italian heritage, although since he would end up growing up in Italy after all, Calvino thought his name sounded "belligerently nationalist". Calvino described his parents as being "very different in personality from one another", suggesting perhaps deeper tensions behind a comfortable, albeit strict, middle-class upbringing devoid of conflict. As an adolescent, he found it hard to relate to poverty and the working-class, and was "ill at ease" with his parents' openness to the labourers who filed into his father's study on Saturdays to receive their weekly paycheck.

Early life and education
In 1925, less than two years after Calvino's birth, the family returned to Italy and settled permanently in Sanremo on the Ligurian coast. Calvino's brother Floriano, who became a distinguished geologist, was born in 1927. The family divided their time between the Villa Meridiana, an experimental floriculture station which also served as their home, and Mario's ancestral land at San Giovanni Battista. On this small working farm set in the hills behind Sanremo, Mario pioneered the cultivation of the then exotic fruits such as avocado and grapefruit, eventually obtaining an entry in the Dizionario biografico degli italiani for his achievements. The vast forests and luxuriant fauna omnipresent in Calvino's early fiction such as The Baron in the Trees derive from this "legacy". In an interview, Calvino stated that "San Remo continues to pop out in my books, in the most diverse pieces of writing."

Calvino and Floriano would climb the tree-rich estate and perch for hours on the branches reading their favourite adventure stories. Less salubrious aspects of this "paternal legacy" are described in The Road to San Giovanni, Calvino's memoir of his father in which he exposes their inability to communicate: "Talking to each other was difficult. Both verbose by nature, possessed of an ocean of words, in each other's presence we became mute, would walk in silence side by side along the road to San Giovanni." A fan of Rudyard Kipling's The Jungle Book as a child, Calvino felt that his early interest in stories made him the "black sheep" of a family that held literature in less esteem than the sciences. Fascinated by American movies and cartoons, he was equally attracted to drawing, poetry, and theatre. On a darker note, Calvino recalled that his earliest memory was of a Marxist professor who had been brutally assaulted by Benito Mussolini's Blackshirts. He said: "I remember clearly that we were at dinner when the old professor came in with his face beaten up and bleeding, his bowtie all torn up over it, asking for help."

Other legacies include the parents' beliefs in Freemasonry, republicanism with elements of anarchism and Marxism. Austere freethinkers with an intense hatred of the ruling National Fascist Party, Eva and Mario also refused to give their sons any education in the Catholic Faith or any other religion. Italo attended the English nursery school St George's College, followed by a Protestant elementary private school run by Waldensians. His secondary schooling, with a classical lyceum curriculum, was completed at the state-run Liceo Gian Domenico Cassini where, at his parents' request, he was exempted from religion classes but frequently asked to justify his anti-conformism to teachers, janitors, and fellow pupils. In his mature years, Calvino described the experience as having made him "tolerant of others' opinions, particularly in the field of religion, remembering how irksome it was to hear myself mocked because I did not follow the majority's beliefs". In 1938, Eugenio Scalfari, who went on to found the weekly magazine L'Espresso and La Repubblica, a major Italian newspaper, came from Civitavecchia to join the same class though a year younger, and they shared the same desk. The two teenagers formed a lasting friendship, Calvino attributing his political awakening to their university discussions. Seated together "on a huge flat stone in the middle of a stream near our land", he and Scalfari founded a university movement called the MUL. Eva managed to delay her son's enrolment in the Party's armed scouts, the Balilla Moschettieri, and then arranged that he be excused, as a non-Catholic, from performing devotional acts in Church. But later on, as a compulsory member, he could not avoid the assemblies and parades of the Avanguardisti, and was forced to participate in the Italian invasion of the French Riviera in June 1940.

World War II
In 1941, Calvino enrolled at the University of Turin, choosing the Agriculture Faculty where his father had previously taught courses in agronomy. Concealing his literary ambitions to please his family, he passed four exams in his first year while reading anti-Fascist works by Elio Vittorini, Eugenio Montale, Cesare Pavese, Johan Huizinga, and Pisacane, and works by Max Planck, Werner Heisenberg, and Albert Einstein on physics. Calvino's real aspiration was to be a playwright. His letters to Eugenio Scalfari overflow with references to Italian and foreign plays, and with plots and characters of future theatrical projects. Luigi Pirandello and Gabriele D'Annunzio, Cesare Vico Lodovici and Ugo Betti,  Eugene O'Neill and Thornton Wilder are among the main authors Calvino cites as his sources of inspiration. Disdainful of Turin students, Calvino saw himself as enclosed in a "provincial shell" that offered the illusion of immunity from the Fascist nightmare: "We were ‘hard guys’ from the provinces, hunters, snooker-players, show-offs, proud of our lack of intellectual sophistication, contemptuous of any patriotic or military rhetoric, coarse in our speech, regulars in the brothels, dismissive of any romantic sentiment and desperately devoid of women."

Calvino transferred to the University of Florence in 1943 and reluctantly passed three more exams in agriculture. By the end of the year, the Germans had succeeded in occupying Liguria and setting up Benito Mussolini's puppet Republic of Salò in northern Italy. Now twenty years old, Calvino refused military service and went into hiding. Reading intensely in a wide array of subjects, he also reasoned politically that, of all the partisan groupings, the communists were the best organized with "the most convincing political line".

In spring 1944, Eva encouraged her sons to enter the Italian Resistance in the name of "natural justice and family virtues". Using the nom de guerre "Santiago", Calvino joined the Garibaldi Brigades, a clandestine Communist group and, for twenty months, endured the fighting in the Maritime Alps until 1945 and the Liberation. As a result of his refusal to be a conscript, his parents were held hostage by the Nazis for an extended period at the Villa Meridiana. Calvino wrote of his mother's ordeal that "she was an example of tenacity and courage… behaving with dignity and firmness before the SS and the Fascist militia, and in her long detention as a hostage, not least when the blackshirts three times pretended to shoot my father in front of her eyes. The historical events which mothers take part in acquire the greatness and invincibility of natural phenomena".

Turin and communism
Calvino settled in Turin in 1945, after a long hesitation over living there or in Milan. He often humorously belittled this choice, describing Turin as a "city that is serious but sad". Returning to university, he abandoned Agriculture for the Arts Faculty. A year later, he was initiated into the literary world by Elio Vittorini, who published his short story "Andato al comando" (1945; "Gone to Headquarters") in Il Politecnico, a Turin-based weekly magazine associated with the university. The horror of the war had not only provided the raw material for his literary ambitions but deepened his commitment to the Communist cause. Viewing civilian life as a continuation of the partisan struggle, he confirmed his membership in the Italian Communist Party. On reading Vladimir Lenin's State and Revolution, he plunged into post-war political life, associating himself chiefly with the worker's movement in Turin.

In 1947, he graduated with a Master's thesis on Joseph Conrad, wrote short stories in his spare time, and landed a job in the publicity department at the Einaudi publishing house run by Giulio Einaudi. Although brief, his stint put him in regular contact with Cesare Pavese, Natalia Ginzburg, Norberto Bobbio, and many other left-wing intellectuals and writers. He then left Einaudi to work as a journalist for the official Communist daily, l'Unità, and the newborn Communist political magazine, Rinascita. During this period, Pavese and poet Alfonso Gatto were Calvino's closest friends and mentors.

His first novel, Il sentiero dei nidi di ragno (The Path to the Nest of Spiders) written with valuable editorial advice from Pavese, won the Premio Riccione on publication in 1947. With sales topping 5000 copies, a surprise success in postwar Italy, the novel inaugurated Calvino's neorealist period. In a clairvoyant essay, Pavese praised the young writer as a "squirrel of the pen" who "climbed into the trees, more for fun than fear, to observe partisan life as a fable of the forest". In 1948, he interviewed one of his literary idols, Ernest Hemingway, travelling with Natalia Ginzburg to his home in Stresa.

Ultimo viene il corvo (The Crow Comes Last), a collection of stories based on his wartime experiences, was published to acclaim in 1949. Despite the triumph, Calvino grew increasingly worried by his inability to compose a worthy second novel. He returned to Einaudi in 1950, responsible this time for the literary volumes. He eventually became a consulting editor, a position that allowed him to hone his writing talent, discover new writers, and develop into "a reader of texts". In late 1951, presumably to advance in the Communist Party, he spent two months in the Soviet Union as a correspondent for l'Unità. While in Moscow, he learned of his father's death on 25 October. The articles and correspondence he produced from this visit were published in 1952, winning the Saint-Vincent Prize for journalism.

Over a seven-year period, Calvino wrote three realist novels, The White Schooner (1947–1949), Youth in Turin (1950–1951), and The Queen's Necklace (1952–54), but all were deemed defective. Calvino's first efforts as a fictionist were marked with his experience in the Italian resistance during the Second World War, however, his acclamation as a writer of fantastic stories came in the 1950s. During the eighteen months it took to complete I giovani del Po (Youth in Turin), he made an important self-discovery: "I began doing what came most naturally to me – that is, following the memory of the things I had loved best since boyhood. Instead of making myself write the book I ought to write, the novel that was expected of me, I conjured up the book I myself would have liked to read, the sort by an unknown writer, from another age and another country, discovered in an attic." The result was Il visconte dimezzato (1952; The Cloven Viscount) composed in 30 days between July and September 1951. The protagonist, a seventeenth-century viscount sundered in two by a cannonball, incarnated Calvino's growing political doubts and the divisive turbulence of the Cold War. Skilfully interweaving elements of the fable and the fantasy genres, the allegorical novel launched him as a modern "fabulist". In 1954, Giulio Einaudi commissioned his Fiabe italiane (1956; Italian Folktales) on the basis of the question, "Is there an Italian equivalent of the Brothers Grimm?" For two years, Calvino collated tales found in 19th century collections across Italy then translated 200 of the finest from various dialects into Italian. Key works he read at this time were Vladimir Propp's Morphology of the Folktale and Historical Roots of Russian Fairy Tales, stimulating his own ideas on the origin, shape and function of the story.

In 1952 Calvino wrote with Giorgio Bassani for Botteghe Oscure, a magazine named after the popular name of the party's head offices in Rome. He also worked for Il Contemporaneo, a Marxist weekly.

From 1955 to 1958 Calvino had an affair with Italian actress Elsa De Giorgi, a married, older woman. Excerpts of the hundreds of love letters Calvino wrote to her were published in the Corriere della Sera in 2004, causing some controversy.

After communism
In 1957, disillusioned by the 1956 Soviet invasion of Hungary, Calvino left the Italian Communist Party. In his letter of resignation published in l'Unità on 7 August, he explained the reason for his dissent (the violent suppression of the Hungarian uprising and the revelation of Joseph Stalin's crimes) while confirming his "confidence in the democratic perspectives" of world Communism. He withdrew from taking an active role in politics and never joined another party. Ostracized by the PCI party leader Palmiro Togliatti and his supporters on publication of Becalmed in the Antilles (La gran bonaccia delle Antille), a satirical allegory of the party's immobilism, Calvino began writing The Baron in the Trees. Completed in three months and published in 1957, the fantasy is based on the "problem of the intellectual's political commitment at a time of shattered illusions". He found new outlets for his periodic writings in the journals Città aperta and Tempo presente, the magazine Passato e presente, and the weekly Italia Domani. With Vittorini in 1959, he became co-editor of 'Il Menabò, a cultural journal devoted to literature in the modern industrial age, a position he held until 1966.

Despite severe restrictions in the US against foreigners holding communist views, Calvino was allowed to visit the United States, where he stayed six months from 1959 to 1960 (four of which he spent in New York), after an invitation by the Ford Foundation. Calvino was particularly impressed by the "New World": "Naturally I visited the South and also California, but I always felt a New Yorker. My city is New York." The letters he wrote to Einaudi describing this visit to the United States were first published as "American Diary 1959–1960" in Hermit in Paris in 2003.

In 1962 Calvino met Argentinian translator Esther Judith Singer ("Chichita") and married her in 1964 in Havana, during a trip in which he visited his birthplace and was introduced to Ernesto "Che" Guevara. On 15 October 1967, a few days after Guevara's death, Calvino wrote a tribute to him that was published in Cuba in 1968, and in Italy thirty years later. He and his wife settled in Rome in via Monte Brianzo where their daughter, Giovanna, was born in 1965. Once again working for Einaudi, Calvino began publishing some of his "Cosmicomics" in Il Caffè, a literary magazine.

Later life and work
Vittorini's death in 1966 greatly affected Calvino. He went through what he called an "intellectual depression", which the writer himself described as an important passage in his life: "I ceased to be young. Perhaps it's a metabolic process, something that comes with age, I'd been young for a long time, perhaps too long, suddenly I felt that I had to begin my old age, yes, old age, perhaps with the hope of prolonging it by beginning it early."

Amid the atmosphere that would evolve into 1968's cultural revolution (the French May), he and his family moved to Paris in 1967, taking up residence in a villa in the Square de Châtillon. Nicknamed l'ironique amusé, Calvino was invited by Raymond Queneau in 1968 to join the Oulipo (Ouvroir de littérature potentielle) group of experimental writers where he met Roland Barthes and Georges Perec, who would influence his later work. That same year, he turned down the Viareggio Prize for Ti con zero (Time and the Hunter) on the grounds that it was an award given by "institutions emptied of meaning". He accepted, however, both the Asti Prize and the Feltrinelli Prize for his writing in 1970 and 1972, respectively. In two autobiographical essays published in 1962 and 1970, Calvino described himself as "atheist" and his outlook as "non-religious".

Calvino had more significant contact with the academic world, notably at the Sorbonne (with Barthes) and the University of Urbino. His literary interests spanned multiple periods, genres, and languages, including Honoré de Balzac, Ludovico Ariosto, Dante, Ignatius of Loyola, Cervantes, Shakespeare, Cyrano de Bergerac, and Giacomo Leopardi.

Between 1972 and 1973, Calvino published two short stories, "The Name, the Nose" and the Oulipo-inspired "The Burning of the Abominable House", in the Italian edition of Playboy. He also became a regular contributor to the Italian newspaper Corriere della Sera. During this period, Calvino spent his summer vacations in a house constructed in the pinewood of Roccamare, in Castiglione della Pescaia, Tuscany.

In 1975, Calvino was made an Honorary Member of the American Academy. Awarded the Austrian State Prize for European Literature in 1976, he visited Mexico, Japan, and the United States, where he gave a series of lectures in several American cities. After his mother died in 1978 at the age of 92, Calvino sold Villa Meridiana, the family home in San Remo. Two years later, he moved to Rome in Piazza Campo Marzio near the Pantheon and began editing the work of Tommaso Landolfi for Rizzoli. Awarded the French Légion d'honneur in 1981, he also accepted the role of jury president for the 38th Venice Film Festival.

During the summer of 1985, Calvino prepared a series of texts on literature for the Charles Eliot Norton Lectures to be delivered at Harvard University in the fall. On 6 September, he was admitted to the hospital of Santa Maria della Scala in Siena (now a museum) where he died during the night between 18 and 19 September of a cerebral haemorrhage. His lecture notes were published posthumously in Italian in 1988 and in English as Six Memos for the Next Millennium in 1993.

Authors he helped publish

 * Mario Rigoni Stern
 * Gianni Celati
 * Andrea De Carlo
 * Daniele Del Giudice
 * Leonardo Sciascia

Selected publications
A selected bibliography of Calvino's writings follows, listing the works that have been published in English translation, along with a few major untranslated works. More exhaustive bibliographies can be found in Martin McLaughlin's Italo Calvino and Beno Weiss's Understanding Italo Calvino.

Selected filmography

 * Boccaccio '70, 1962 (co-wrote screenplay of "Renzo e Luciano" segment directed by Mario Monicelli)
 * L'Amore difficile, 1963 (wrote "L'avventura di un soldato" segment directed by Nino Manfredi)
 * Tiko and the Shark, 1964 (co-wrote screenplay directed by Folco Quilici)

Film and television adaptations

 * The Nonexistent Knight by Pino Zac, 1969 (Italian animated film based on the novel)
 * Amores dificiles by Ana Luisa Ligouri, 1983 (13' Mexican short)
 * L'Aventure d'une baigneuse by Philippe Donzelot, 1991 (14' French short based on The Adventure of a Bather in Difficult Loves )
 * Fantaghirò by Lamberto Bava, 1991 (TV adaptation based on Fanta-Ghirò the Beautiful in Italian Folktales)
 * Palookaville by Alan Taylor, 1995 (American film based on Theft in a Cake Shop, Desire in November, and Transit Bed)
 * Solidarity by Nancy Kiang, 2006 (10' American short)
 * Conscience by Yu-Hsiu Camille Chen, 2009 (10' Australian short)
 * "La Luna" by Enrico Casarosa, 2011 (American short loosely based on "The Distance of the Moon" from Cosmicomics.)

Films on Calvino

 * Damian Pettigrew, Lo specchio di Calvino, 2012 . Co-produced by Arte France, Italy's Ministero per i Beni e le Attività Culturali, and the National Film Board of Canada, the feature-length docufiction stars Neri Marcorè as the Italian writer alongside distinguished literary critic Pietro Citati. The film also uses in-depth interviews conducted at Calvino's Rome residence a year before his death in 1985 and rare footage from RAI, INA (Institut national de l'audiovisuel), and BBC television archives. The 52-minute French version titled, Dans la peau d'Italo Calvino ("Being Italo Calvino"), was broadcast by Arte France on 19 December 2012 and Sky Arte (Italy) on 14 October 2013.

Legacy
The Scuola Italiana Italo Calvino, an Italian curriculum school in Moscow, Russia, is named after him. A crater on the planet Mercury, Calvino, and a main-belt asteroid, 22370 Italocalvino, are also named after him. Salt Hill Journal and University of Louisville award annually the Italo Calvino Prize "for a work of fiction written in the fabulist experimental style of Italo Calvino".

Kai Nieminen (b. 1953) wrote his flute concerto (2001) based on the story of Mr. Palomar. The text was written to the dedicatee, Patrick Gallois.

Awards

 * 1946 – l'Unità Prize (shared with Marcello Venturi) for the short story, Minefield (Campo di mine)
 * 1947 – Riccione Prize for The Path to the Nest of Spiders
 * 1952 – Saint-Vincent Prize
 * 1957 – Viareggio Prize for The Baron in the Trees
 * 1959 – Bagutta Prize
 * 1960 – Salento Prize for Our Ancestors
 * 1963 – International Charles Veillon Prize for The Watcher
 * 1970 – Asti Prize
 * 1974 - Prix Médicis étranger for Invisible Cities
 * 1972 – Feltrinelli Prize for Invisible Cities
 * 1976 – Austrian State Prize for European Literature
 * 1982 – World Fantasy Award – Life Achievement

Online sources

 * Italo Calvino at Emory University Online Resources and Links
 * Outside the Town of Malbork A Site for Italo Calvino
 * The Words that Failed Calvino on Che Guevara
 * http://atlantecalvino.unige.ch/ vizualisation of Calvino's work by

license: Creative Commons - Attribution Share-Alike - https://creativecommons.org/licenses/by-sa/4.0/

title: Italo Calvino


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Intercontinental ballistic missile

An intercontinental ballistic missile (ICBM) is a ballistic missile with a range greater than 5500 km, primarily designed for nuclear weapons delivery (delivering one or more thermonuclear warheads). Conventional, chemical, and biological weapons can also be delivered with varying effectiveness, but have never been deployed on ICBMs. Most modern designs support multiple independently targetable reentry vehicle (MIRVs), allowing a single missile to carry several warheads, each of which can strike a different target. The United States, Russia, China, France, India, the United Kingdom, Israel, and North Korea are the only countries known to have operational ICBMs.

Early ICBMs had limited precision, which made them suitable for use only against the largest targets, such as cities. They were seen as a "safe" basing option, one that would keep the deterrent force close to home where it would be difficult to attack. Attacks against military targets (especially hardened ones) demanded the use of a more precise, crewed bomber. Second- and third-generation designs (such as the LGM-118 Peacekeeper) dramatically improved accuracy to the point where even the smallest point targets can be successfully attacked.

ICBMs are differentiated by having greater range and speed than other ballistic missiles: intermediate-range ballistic missiles (IRBMs), medium-range ballistic missiles (MRBMs), short-range ballistic missiles (SRBMs) and tactical ballistic missiles.

World War II
The first practical design for an ICBM grew out of Nazi Germany's V-2 rocket program. The liquid-fueled V-2, designed by Wernher von Braun and his team, was then widely used by Nazi Germany from mid-1944 until March 1945 to bomb British and Belgian cities, particularly Antwerp and London.

Under Projekt Amerika, von Braun's team developed the A9/10 ICBM, intended for use in bombing New York and other American cities. Initially intended to be guided by radio, it was changed to be a piloted craft after the failure of Operation Elster. The second stage of the A9/A10 rocket was tested a few times in January and February 1945.

After the war, the US executed Operation Paperclip, which took von Braun and hundreds of other leading Nazi scientists to the United States to develop IRBMs, ICBMs, and launchers for the US Army.

This technology was predicted by US General of the Army Hap Arnold, who wrote in 1943: "Someday, not too distant, there can come streaking out of somewhere – we won't be able to hear it, it will come so fast – some kind of gadget with an explosive so powerful that one projectile will be able to wipe out completely this city of Washington."

Cold War
After World War II, the Americans and the Soviets started rocket research programs based on the V-2 and other German wartime designs. Each branch of the US military started its own programs, leading to considerable duplication of effort. In the Soviet Union, rocket research was centrally organized although several teams worked on different designs.

In the Soviet Union, early development was focused on missiles able to attack European targets. That changed in 1953, when Sergei Korolyov was directed to start development of a true ICBM able to deliver newly developed hydrogen bombs. Given steady funding throughout, the R-7 developed with some speed. The first launch took place on 15 May 1957 and led to an unintended crash 400 km from the site. The first successful test followed on 21 August 1957; the R-7 flew over 6000 km and became the world's first ICBM. The first strategic-missile unit became operational on 9 February 1959 at Plesetsk in north-west Russia.

It was the same R-7 launch vehicle that placed the first artificial satellite in space, Sputnik, on 4 October 1957. The first human spaceflight in history was accomplished on a derivative of R-7, Vostok, on 12 April 1961, by Soviet cosmonaut Yuri Gagarin. A heavily modernized version of the R-7 is still used as the launch vehicle for the Soviet/Russian Soyuz spacecraft, marking more than 60 years of operational history of Sergei Korolyov's original rocket design.

The US initiated ICBM research in 1946 with the RTV-A-2 Hiroc project. This was a three-stage effort with the ICBM development not starting until the third stage. However, funding was cut in 1948 after only three partially successful launches of the second stage design, that was used to test variations of the V-2 design. With overwhelming air superiority and truly intercontinental bombers, the newly formed US Air Force did not take the problem of ICBM development seriously. Things changed in 1953 with the Soviet testing of their first thermonuclear weapon, but it was not until 1954 that the Atlas missile program was given the highest national priority. The Atlas A first flew on 11 June 1957; the flight lasted only about 24 seconds before the rocket exploded. The first successful flight of an Atlas missile to full range occurred 28 November 1958. The first armed version of the Atlas, the Atlas D, was declared operational in January 1959 at Vandenberg, although it had not yet flown. The first test flight was carried out on 9 July 1959, and the missile was accepted for service on 1 September. The Titan I was another US multistage ICBM, with a successful launch February 5, 1959, with Titan I A3. Unlike the Atlas, the Titan I was a two-stage missile, rather than three. The Titan was larger, yet lighter, than the Atlas. Due to the improvements in engine technology and guidance systems the Titan I overtook the Atlas.

The R-7 and Atlas each required a large launch facility, making them vulnerable to attack, and could not be kept in a ready state. Failure rates were very high throughout the early years of ICBM technology. Human spaceflight programs (Vostok, Mercury, Voskhod, Gemini, etc.) served as a highly visible means of demonstrating confidence in reliability, with successes translating directly to national defense implications. The US was well behind the Soviets in the Space Race and so US President John F. Kennedy increased the stakes with the Apollo program, which used Saturn rocket technology that had been funded by President Dwight D. Eisenhower.

These early ICBMs also formed the basis of many space launch systems. Examples include R-7, Atlas, Redstone, Titan, and Proton, which was derived from the earlier ICBMs but never deployed as an ICBM. The Eisenhower administration supported the development of solid-fueled missiles such as the LGM-30 Minuteman, Polaris and Skybolt. Modern ICBMs tend to be smaller than their ancestors, due to increased accuracy and smaller and lighter warheads, and use solid fuels, making them less useful as orbital launch vehicles.

The Western view of the deployment of these systems was governed by the strategic theory of mutual assured destruction. In the 1950s and 1960s, development began on anti-ballistic missile systems by both the Americans and Soviets. Such systems were restricted by the 1972 Anti-Ballistic Missile Treaty. The first successful ABM test was conducted by the Soviets in 1961, which later deployed a fully operational system defending Moscow in the 1970s (see Moscow ABM system).

The 1972 SALT treaty froze the number of ICBM launchers of both the Americans and the Soviets at existing levels and allowed new submarine-based SLBM launchers only if an equal number of land-based ICBM launchers were dismantled. Subsequent talks, called SALT II, were held from 1972 to 1979 and actually reduced the number of nuclear warheads held by the US and Soviets. SALT II was never ratified by the US Senate, but its terms were honored by both sides until 1986, when the Reagan administration "withdrew" after it had accused the Soviets of violating the pact.

In the 1980s, President Ronald Reagan launched the Strategic Defense Initiative as well as the MX and Midgetman ICBM programs.

China developed a minimal independent nuclear deterrent entering its own cold war after an ideological split with the Soviet Union beginning in the early 1960s. After first testing a domestic built nuclear weapon in 1964, it went on to develop various warheads and missiles. Beginning in the early 1970s, the liquid fuelled DF-5 ICBM was developed and used as a satellite launch vehicle in 1975. The DF-5, with a range of 10000 to 12000 km—long enough to strike the Western United States and the Soviet Union—was silo deployed, with the first pair in service by 1981 and possibly twenty missiles in service by the late 1990s. China also deployed the JL-1 Medium-range ballistic missile with a reach of 1700 km aboard the ultimately unsuccessful type 92 submarine.

Post–Cold War
In 1991, the United States and the Soviet Union agreed in the START I treaty to reduce their deployed ICBMs and attributed warheads.

, all five of the nations with permanent seats on the United Nations Security Council have fully operational long-range ballistic missile systems; Russia, the United States, and China also have land-based ICBMs (the US missiles are silo-based, while China and Russia have both silo and road-mobile (DF-31, RT-2PM2 Topol-M missiles).

Israel is believed to have deployed a road mobile nuclear ICBM, the Jericho III, which entered service in 2008; an upgraded version is in development.

India successfully test fired Agni V, with a strike range of more than 5000 km on 19 April 2012, claiming entry into the ICBM club. The missile's actual range is speculated by foreign researchers to be up to 8000 km with India having downplayed its capabilities to avoid causing concern to other countries. On 15 December 2022, first night trial of Agni-V was successfully carried out by SFC from Abdul Kalam Island, Odisha. The missile is now 20 percent lighter because the use of composite materials rather than steel material. The range has been increased to 7,000 km.

By 2012 there was speculation by some intelligence agencies that North Korea is developing an ICBM. North Korea successfully put a satellite into space on 12 December 2012 using the 32 m Unha-3 rocket. The United States claimed that the launch was in fact a way to test an ICBM. (See Timeline of first orbital launches by country.) In early July 2017, North Korea claimed for the first time to have tested successfully an ICBM capable of carrying a large thermonuclear warhead.

In July 2014, China announced the development of its newest generation of ICBM, the Dongfeng-41 (DF-41), which has a range of 12,000 km, capable of reaching the United States, and which analysts believe is capable of being outfitted with MIRV technology.

Most countries in the early stages of developing ICBMs have used liquid propellants, with the known exceptions being the Indian Agni-V, the planned but cancelled South African RSA-4 ICBM, and the now in service Israeli Jericho III.

The RS-28 Sarmat (Russian: РС-28 Сармат; NATO reporting name: SATAN 2), is a Russian liquid-fueled, MIRV-equipped, super-heavy thermonuclear armed intercontinental ballistic missile in development by the Makeyev Rocket Design Bureau from 2009, intended to replace the previous R-36 missile. Its large payload would allow for up to 10 heavy warheads or 15 lighter ones or up to 24 hypersonic glide vehicles Yu-74, or a combination of warheads and massive amounts of countermeasures designed to defeat anti-missile systems; it was announced by the Russian military as a response to the US Prompt Global Strike.

In July 2023, North Korea fired a suspected intercontinental ballistic missile that was expected to land short of Japanese waters. The launch follows North Korea's threat to retaliate against the US for alleged spy plane incursions.

Flight phases
The following flight phases can be distinguished:

 * 1) Boost phase, which can last from 3 to 5 minutes. It is shorter for a solid-fuel rocket than for a liquid-propellant rocket. Depending on the trajectory chosen, typical burnout speed is 4 km/s, up to 7.8 km/s. The altitude of the missile at the end of this phase is typically 150 to 400 km.
 * 2) Midcourse phase, which lasts approx. 25 minutes, is sub-orbital spaceflight with the flightpath being a part of an ellipse with a vertical major axis. The apogee (halfway through the midcourse phase) is at an altitude of approximately 1200 km. The semi-major axis is between 3186 and 6372 km and the projection of the flightpath on the Earth's surface is close to a great circle, though slightly displaced due to earth rotation during the time of flight. In this phase, the missile may release several independent warheads and penetration aids, such as metallic-coated balloons, aluminum chaff, and full-scale warhead decoys.
 * 3) Reentry/Terminal phase, which lasts two minutes starting at an altitude of 100 km. At the end of this phase, the missile's payload will impact the target, with impact at a speed of up to 7 km/s (for early ICBMs less than 1 km/s); see also maneuverable reentry vehicle.

ICBMs usually use the trajectory which optimizes range for a given amount of payload (the minimum-energy trajectory); an alternative is a depressed trajectory, which allows less payload, shorter flight time, and has a much lower apogee.

Modern ICBMs
Modern ICBMs typically carry multiple independently targetable reentry vehicles (MIRVs), each of which carries a separate nuclear warhead, allowing a single missile to hit multiple targets. MIRV was an outgrowth of the rapidly shrinking size and weight of modern warheads and the Strategic Arms Limitation Treaties (SALT I and SALT II), which imposed limitations on the number of launch vehicles. It has also proved to be an "easy answer" to proposed deployments of anti-ballistic missile (ABM) systems: It is far less expensive to add more warheads to an existing missile system than to build an ABM system capable of shooting down the additional warheads; hence, most ABM system proposals have been judged to be impractical. The first operational ABM systems were deployed in the United States during the 1970s. The Safeguard ABM facility, located in North Dakota, was operational from 1975 to 1976. The Soviets deployed their ABM-1 Galosh system around Moscow in the 1970s, which remains in service. Israel deployed a national ABM system based on the Arrow missile in 1998, but it is mainly designed to intercept shorter-ranged theater ballistic missiles, not ICBMs. The Alaska-based United States national missile defense system attained initial operational capability in 2004.

ICBMs can be deployed from multiple platforms: The last three kinds are mobile and therefore hard to detect prior to a missile launch. During storage, one of the most important features of the missile is its serviceability. One of the key features of the first computer-controlled ICBM, the Minuteman missile, was that it could quickly and easily use its computer to test itself.
 * In missile silos, which offer some protection from military attack (including, the designers hope, some protection from a nuclear first strike)
 * On submarines: submarine-launched ballistic missiles (SLBMs); most or all SLBMs have the long range of ICBMs (as opposed to IRBMs)
 * On heavy trucks: this applies to one version of the Topol which may be deployed from a self-propelled mobile launcher, capable of moving through roadless terrain, and launching a missile from any point along its route
 * Mobile launchers on rails; this applies, for example, to РТ-23УТТХ "Молодец" (RT-23UTTH "Molodets" – SS-24 "Scalpel")

After launch, a booster pushes the missile and then falls away. Most modern boosters are Solid-propellant rocket motors, which can be stored easily for long periods of time. Early missiles used liquid-fueled rocket motors. Many liquid-fueled ICBMs could not be kept fueled at all times as the cryogenic fuel liquid oxygen boiled off and caused ice formation, and therefore fueling the rocket was necessary before launch. This procedure was a source of significant operational delay and might allow the missiles to be destroyed by enemy counterparts before they could be used. To resolve this problem Nazi Germany invented the missile silo that protected the missile from Strategic Bombing and also hid fueling operations underground.

Although the USSR/Russia preferred ICBM designs, that use hypergolic liquid fuels, which can be stored at room temperature for more than a few years.

Once the booster falls away, the remaining "bus" releases several warheads, each of which continues on its own unpowered ballistic trajectory, much like an artillery shell or cannonball. The warhead is encased in a cone-shaped reentry vehicle and is difficult to detect in this phase of flight as there is no rocket exhaust or other emissions to mark its position to defenders. The high speeds of the warheads make them difficult to intercept and allow for little warning, striking targets many thousands of kilometers away from the launch site (and due to the possible locations of the submarines: anywhere in the world) within approximately 30 minutes.

Many authorities say that missiles also release aluminized balloons, electronic noisemakers, and other decoys intended to confuse interception devices and radars.

As the nuclear warhead reenters the Earth's atmosphere, its high speed causes compression of the air, leading to a dramatic rise in temperature which would destroy it, if it were not shielded in some way. In one design, warhead components are contained within an aluminium honeycomb substructure, sheathed in a pyrolytic carbon-epoxy synthetic resin composite material heat shield. Warheads are also often radiation-hardened (to protect against nuclear armed ABMs or the nearby detonation of friendly warheads), one neutron-resistant material developed for this purpose in the UK is three-dimensional quartz phenolic.

Circular error probable is crucial, because halving the circular error probable decreases the needed warhead energy by a factor of four. Accuracy is limited by the accuracy of the navigation system and the available geodetic information.

Strategic missile systems are thought to use custom integrated circuits designed to calculate navigational differential equations thousands to millions of FLOPS in order to reduce navigational errors caused by calculation alone. These circuits are usually a network of binary addition circuits that continually recalculate the missile's position. The inputs to the navigation circuit are set by a general-purpose computer according to a navigational input schedule loaded into the missile before launch.

One particular weapon developed by the Soviet Union – the Fractional Orbital Bombardment System – had a partial orbital trajectory, and unlike most ICBMs its target could not be deduced from its orbital flight path. It was decommissioned in compliance with arms control agreements, which address the maximum range of ICBMs and prohibit orbital or fractional-orbital weapons. However, according to reports, Russia is working on the new Sarmat ICBM which leverages Fractional Orbital Bombardment concepts to use a Southern polar approach instead of flying over the northern polar regions. Using that approach, it is theorized, avoids the American missile defense batteries in California and Alaska.

New development of ICBM technology are ICBMs able to carry hypersonic glide vehicles as a payload such as RS-28 Sarmat.

In March 12 2024 India announced that it had joined a very limited group of countries, which are capable of firing multiple warheads on a single ICBM. The announcement came after successfully testing multiple independently targetable reentry vehicle (MIRV) technology.

Land-based ICBMs

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Russia, the United States, China, North Korea, India and Israel are the only countries currently known to possess land-based ICBMs.

The United States currently operates 405 ICBMs in three USAF bases. The only model deployed is LGM-30G Minuteman-III. All previous USAF Minuteman II missiles were destroyed in accordance with START II, and their launch silos have been sealed or sold to the public. The powerful MIRV-capable Peacekeeper missiles were phased out in 2005.

The Russian Strategic Rocket Forces have 286 ICBMs able to deliver 958 nuclear warheads: 46 silo-based R-36M2 (SS-18), 30 silo-based UR-100N (SS-19), 36 mobile RT-2PM "Topol" (SS-25), 60 silo-based RT-2UTTH "Topol M" (SS-27), 18 mobile RT-2UTTH "Topol M" (SS-27), 84 mobile RS-24 "Yars" (SS-29), and 12 silo-based RS-24 "Yars" (SS-29).

China has developed several long-range ICBMs, like the DF-31. The Dongfeng 5 or DF-5 is a 3-stage liquid fuel ICBM and has an estimated range of 13,000 kilometers. The DF-5 had its first flight in 1971 and was in operational service 10 years later. One of the downsides of the missile was that it took between 30 and 60 minutes to fuel. The Dong Feng 31 (a.k.a. CSS-10) is a medium-range, three-stage, solid-propellant intercontinental ballistic missile, and is a land-based variant of the submarine-launched JL-2.

The DF-41 or CSS-X-10 can carry up to 10 nuclear warheads, which are MIRVs and has a range of approximately 12000 –. The DF-41 deployed underground in Xinjiang, Qinghai, Gansu and Inner Mongolia. The mysterious underground subway ICBM carrier systems are called the "Underground Great Wall Project".

Israel is believed to have deployed a road mobile nuclear ICBM, the Jericho III, which entered service in 2008. It is possible for the missile to be equipped with a single 750 kg nuclear warhead or up to three MIRV warheads. It is believed to be based on the Shavit space launch vehicle and is estimated to have a range of 4800 to 11500 km. In November 2011 Israel tested an ICBM believed to be an upgraded version of the Jericho III.

India has a series of ballistic missiles called Agni. On 19 April 2012, India successfully test fired its first Agni-V, a three-stage solid fueled missile, with a strike range of more than 7500 km. Missile was test-fired for the second time on 15 September 2013. On 31 January 2015, India conducted a third successful test flight of the Agni-V from the Abdul Kalam Island facility. The test used a canisterised version of the missile, mounted over a Tata truck. On 15 December 2022, first night trial of Agni-V was successfully carried out by SFC from Abdul Kalam Island, Odisha. The missile is now 20 percent lighter because the use of composite materials rather than steel material. The range has been increased to 7,000 km.

Submarine-launched ICBMs
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Missile defense
An anti-ballistic missile is a missile which can be deployed to counter an incoming nuclear or non-nuclear ICBM. ICBMs can be intercepted in three regions of their trajectory: boost phase, mid-course phase or terminal phase. The United States, Russia, India, France, Israel, and China have now developed anti-ballistic missile systems, of which the Russian A-135 anti-ballistic missile system, the American Ground-Based Midcourse Defense, the Indian Prithvi Defence Vehicle Mark-II and the Israeli Arrow 3 are the only systems having the capability to intercept and shoot down ICBMs carrying nuclear, chemical, biological, or conventional warheads.

title: Intercontinental ballistic missile


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Irish traditional music session

Irish traditional music sessions are mostly informal gatherings at which people play Irish traditional music. The Irish language word for "session" is seisiún. This article discusses tune-playing, although "session" can also refer to a singing session or a mixed session (tunes and songs).

Barry Foy's Field Guide to the Irish Music Session defines a session as: ...a gathering of Irish traditional musicians for the purpose of celebrating their common interest in the music by playing it together in a relaxed, informal setting, while in the process generally beefing up the mystical cultural mantra that hums along uninterruptedly beneath all manifestations of Irishness worldwide.

Social and cultural aspects
The general session scheme is that someone starts a tune, and those who know it join in. Good session etiquette requires not playing if one does not know the tune (or at least quietly playing an accompaniment part) and waiting until a tune one knows comes along. In an "open" session, anyone who is able to play Irish music is welcome. Most often there are more-or-less recognized session leaders; sometimes there are no leaders. At times a song will be sung or a slow air played by a single musician between sets.

Locations and times
Sessions are usually held in public houses or taverns. A pub owner might have one or two musicians paid to come regularly in order for the session to have a base. These musicians can perform during any gaps during the day or evening when no other performers are there and wish to play. Sunday afternoons and weekday nights (especially Tuesday and Wednesday) are common times for sessions to be scheduled, on the theory that these are the least likely times for dances and concerts to be held, and therefore the times that professional musicians will be most able to show up.

Sessions can be held in homes or at various public places in addition to pubs; often at a festival sessions will be got together in the beer tent or in the vendor's booth of a music-loving craftsperson or dealer. When a particularly large musical event "takes over" an entire village, spontaneous sessions may erupt on the street corners. Sessions may also take place occasionally at wakes. House sessions are not as common now as they were in the past. In her book Peig, Peig Sayers notes that when she was young they often attended sessions at people's houses, in a practice called 'bothántiocht'.

title: Irish traditional music session


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Ice

Ice is water that is frozen into a solid state, typically forming at or below temperatures of 0 °C, 32 °F, or 273.15 K. It occurs naturally on Earth, on other planets, in Oort cloud objects, and as interstellar ice. As a naturally occurring crystalline inorganic solid with an ordered structure, ice is considered to be a mineral. Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaque bluish-white color.

Virtually all of the ice on Earth is of a hexagonal crystalline structure denoted as ice Ih (spoken as "ice one h"). Depending on temperature and pressure, at least nineteen phases (packing geometries) can exist. The most common phase transition to ice Ih occurs when liquid water is cooled below $0.36$ ($5.5$, $0 °C$) at standard atmospheric pressure. When water is cooled rapidly (quenching), up to three types of amorphous ice can form. Interstellar ice is overwhelmingly low-density amorphous ice (LDA), which likely makes LDA ice the most abundant type in the universe. When cooled slowly, correlated proton tunneling occurs below $273.15 K$ ($32 °F$, $-253.15 °C$) giving rise to macroscopic quantum phenomena.

Ice is abundant on the Earth's surface, particularly in the polar regions and above the snow line, where it can aggregate from snow to form glaciers and ice sheets. As snowflakes and hail, ice is a common form of precipitation, and it may also be deposited directly by water vapor as frost. The transition from ice to water is melting and from ice directly to water vapor is sublimation. These processes plays a key role in Earth's water cycle and climate. In the recent decades, ice volume on Earth has been decreasing due to climate change. The largest declines have occurred in the Arctic and in the mountains located outside of the polar regions. The loss of grounded ice (as opposed to floating sea ice) is the primary contributor to sea level rise.

Humans have been using ice for various purposes for thousands of years. Some historic structures designed to hold ice to provide cooling are over 2,000 years old. Before the invention of refrigeration technology, the only way to safely store food without modifying it through preservatives was to use ice. Sufficiently solid surface ice makes waterways accessible to land transport during winter, and dedicated ice roads may be maintained. Ice also plays a major role in winter sports.

Physical properties

Ice possesses a regular crystalline structure based on the molecule of water, which consists of a single oxygen atom covalently bonded to two hydrogen atoms, or H–O–H. However, many of the physical properties of water and ice are controlled by the formation of hydrogen bonds between adjacent oxygen and hydrogen atoms; while it is a weak bond, it is nonetheless critical in controlling the structure of both water and ice.

An unusual property of water is that its solid form—ice frozen at atmospheric pressure—is approximately 8.3% less dense than its liquid form; this is equivalent to a volumetric expansion of 9%. The density of ice is 0.9167 –0.9168 g/cm3 at 0 °C and standard atmospheric pressure (101,325 Pa), whereas water has a density of 0.9998 –0.999863 g/cm3 at the same temperature and pressure. Liquid water is densest, essentially 1.00 g/cm3, at 4 °C and begins to lose its density as the water molecules begin to form the hexagonal crystals of ice as the freezing point is reached. This is due to hydrogen bonding dominating the intermolecular forces, which results in a packing of molecules less compact in the solid. Density of ice increases slightly with decreasing temperature and has a value of 0.9340 g/cm3 at −180 °C (93 K).

When water freezes, it increases in volume (about 9% for fresh water). The effect of expansion during freezing can be dramatic, and ice expansion is a basic cause of freeze-thaw weathering of rock in nature and damage to building foundations and roadways from frost heaving. It is also a common cause of the flooding of houses when water pipes burst due to the pressure of expanding water when it freezes.

Because ice is less dense than liquid water, it floats, and this prevents bottom-up freezing of the bodies of water. Instead, a sheltered environment for animal and plant life is formed beneath the floating ice, which protects the underside from short-term weather extremes such as wind chill. Sufficiently thin floating ice allows light to pass through, supporting the photosynthesis of bacterial and algal colonies. When sea water freezes, the ice is riddled with brine-filled channels which sustain sympagic organisms such as bacteria, algae, copepods and annelids. In turn, they provide food for animals such as krill and specialized fish like the bald notothen, fed upon in turn by larger animals such as emperor penguins and minke whales.

When ice melts, it absorbs as much energy as it would take to heat an equivalent mass of water by 80 C. During the melting process, the temperature remains constant at 0 C. While melting, any energy added breaks the hydrogen bonds between ice (water) molecules. Energy becomes available to increase the thermal energy (temperature) only after enough hydrogen bonds are broken that the ice can be considered liquid water. The amount of energy consumed in breaking hydrogen bonds in the transition from ice to water is known as the heat of fusion.

As with water, ice absorbs light at the red end of the spectrum preferentially as the result of an overtone of an oxygen–hydrogen (O–H) bond stretch. Compared with water, this absorption is shifted toward slightly lower energies. Thus, ice appears blue, with a slightly greener tint than liquid water. Since absorption is cumulative, the color effect intensifies with increasing thickness or if internal reflections cause the light to take a longer path through the ice. Other colors can appear in the presence of light absorbing impurities, where the impurity is dictating the color rather than the ice itself. For instance, icebergs containing impurities (e.g., sediments, algae, air bubbles) can appear brown, grey or green.

Because ice in natural environments is usually close to its melting temperature, its hardness shows pronounced temperature variations. At its melting point, ice has a Mohs hardness of 2 or less, but the hardness increases to about 4 at a temperature of -44 C and to 6 at a temperature of -78.5 C, the vaporization point of solid carbon dioxide (dry ice).

Phases

Most liquids under increased pressure freeze at higher temperatures because the pressure helps to hold the molecules together. However, the strong hydrogen bonds in water make it different: for some pressures higher than 1 atm, water freezes at a temperature below 0 C. Ice, water, and water vapour can coexist at the triple point, which is exactly 273.16 K at a pressure of 611.657 Pa. The kelvin was defined as $20 K$ of the difference between this triple point and absolute zero, though this definition changed in May 2019. Unlike most other solids, ice is difficult to superheat. In an experiment, ice at −3 °C was superheated to about 17 °C for about 250picoseconds.

Subjected to higher pressures and varying temperatures, ice can form in nineteen separate known crystalline phases at various densities, along with hypothetical proposed phases of ice that have not been observed. With care, at least fifteen of these phases (one of the known exceptions being ice X) can be recovered at ambient pressure and low temperature in metastable form. The types are differentiated by their crystalline structure, proton ordering, and density. There are also two metastable phases of ice under pressure, both fully hydrogen-disordered; these are Ice IV and Ice XII. Ice XII was discovered in 1996. In 2006, Ice XIII and Ice XIV were discovered. Ices XI, XIII, and XIV are hydrogen-ordered forms of ices I$-423.67 °F$, V, and XII respectively. In 2009, ice XV was found at extremely high pressures and −143 °C. At even higher pressures, ice is predicted to become a metal; this has been variously estimated to occur at 1.55 TPa or 5.62 TPa.

As well as crystalline forms, solid water can exist in amorphous states as amorphous solid water (ASW) of varying densities. In outer space, hexagonal crystalline ice is present in the ice volcanoes, but is extremely rare otherwise. Even icy moons like Ganymede are expected to mainly consist of other crystalline forms of ice. Water in the interstellar medium is dominated by amorphous ice, making it likely the most common form of water in the universe. Low-density ASW (LDA), also known as hyperquenched glassy water, may be responsible for noctilucent clouds on Earth and is usually formed by deposition of water vapor in cold or vacuum conditions. High-density ASW (HDA) is formed by compression of ordinary ice I$2$ or LDA at GPa pressures. Very-high-density ASW (VHDA) is HDA slightly warmed to 160 K under 1–2 GPa pressures.

Ice from a theorized superionic water may possess two crystalline structures. At pressures in excess of 500000 bar such superionic ice would take on a body-centered cubic structure. However, at pressures in excess of 1000000 bar the structure may shift to a more stable face-centered cubic lattice. It is speculated that superionic ice could compose the interior of ice giants such as Uranus and Neptune.

Friction properties
Ice is "slippery" because it has a low coefficient of friction. This subject was first scientifically investigated in the 19th century. The preferred explanation at the time was "pressure melting" -i.e. the blade of an ice skate, upon exerting pressure on the ice, would melt a thin layer, providing sufficient lubrication for the blade to glide across the ice. Yet, 1939 research by Frank P. Bowden and T. P. Hughes found that skaters would experience a lot more friction than they actually do if it were the only explanation. Further, the optimum temperature for figure skating is -5.5 C and −9 C for hockey; yet, according to pressure melting theory, skating below −4 C would be outright impossible. Instead, Bowden and Hughes argued that heating and melting of the ice layer is caused by friction. However, this theory does not sufficiently explain why ice is slippery when standing still even at below-zero temperatures.

Subsequent research suggested that ice molecules at the interface cannot properly bond with the molecules of the mass of ice beneath (and thus are free to move like molecules of liquid water). These molecules remain in a semi-liquid state, providing lubrication regardless of pressure against the ice exerted by any object. However, the significance of this hypothesis is disputed by experiments showing a high coefficient of friction for ice using atomic force microscopy. Thus, the mechanism controlling the frictional properties of ice is still an active area of scientific study. A comprehensive theory of ice friction must take into account all of the aforementioned mechanisms to estimate friction coefficient of ice against various materials as a function of temperature and sliding speed. 2014 research suggests that frictional heating is the most important process under most typical conditions.

Natural formation
The term that collectively describes all of the parts of the Earth's surface where water is in frozen form is the cryosphere. Ice is an important component of the global climate, particularly in regard to the water cycle. Glaciers and snowpacks are an important storage mechanism for fresh water; over time, they may sublimate or melt. Snowmelt is an important source of seasonal fresh water. The World Meteorological Organization defines several kinds of ice depending on origin, size, shape, influence and so on. Clathrate hydrates are forms of ice that contain gas molecules trapped within its crystal lattice.

In the oceans
Ice that is found at sea may be in the form of drift ice floating in the water, fast ice fixed to a shoreline or anchor ice if attached to the seafloor. Ice which calves (breaks off) from an ice shelf or a coastal glacier may become an iceberg. The aftermath of calving events produces a loose mixture of snow and ice known as Ice mélange.

Sea ice forms in several stages. At first, small, millimeter-scale crystals accumulate on the water surface in what is known as frazil ice. As they become somewhat larger and more consistent in shape and cover, the water surface begins to look "oily" from above, so this stage is called grease ice. Then, ice continues to clump together, and solidify into flat cohesive pieces known as ice floes. Ice floes are the basic building blocks of sea ice cover, and their horizontal size (defined as half of their diameter) varies dramatically, with the smallest measured in centimeters and the largest in hundreds of kilometers. An area which is over 70% ice on its surface is said to be covered by pack ice.

Fully formed sea ice can be forced together by currents and winds to form pressure ridges up to 12 m tall. On the other hand, active wave activity can reduce sea ice to small, regularly shaped pieces, known as pancake ice. Sometimes, wind and wave activity "polishes" sea ice to perfectly spherical pieces known as ice eggs.

On land
The largest ice formations on Earth are the two ice sheets which almost completely cover the world's largest island, Greenland, and the continent of Antarctica. These ice sheets have an average thickness of over 1 km and have existed for millions of years.

Other major ice formations on land include ice caps, ice fields, ice streams and glaciers. In particular, the Hindu Kush region is known as the Earth's "Third Pole" due to the large number of glaciers it contains. They cover an area of around 80,000 sqkm, and have a combined volume of between 3,000-4,700 km3. These glaciers are nicknamed "Asian water towers", because their meltwater run-off feeds into rivers which provide water for an estimated two billion people.

Permafrost refers to soil or underwater sediment which continuously remains below 0 C for two years or more. The ice within permafrost is divided into four categories: pore ice, vein ice (also known as ice wedges), buried surface ice and intrasedimental ice (from the freezing of underground waters). One example of ice formation in permafrost areas is aufeis - layered ice that forms in Arctic and subarctic stream valleys. Ice, frozen in the stream bed, blocks normal groundwater discharge, and causes the local water table to rise, resulting in water discharge on top of the frozen layer. This water then freezes, causing the water table to rise further and repeat the cycle. The result is a stratified ice deposit, often several meters thick. Snow line and snow fields are two related concepts, in that snow fields accumulate on top of and ablate away to the equilibrium point (the snow line) in an ice deposit.

On rivers and streams
Ice which forms on moving water tends to be less uniform and stable than ice which forms on calm water. Ice jams (sometimes called "ice dams"), when broken chunks of ice pile up, are the greatest ice hazard on rivers. Ice jams can cause flooding, damage structures in or near the river, and damage vessels on the river. Ice jams can cause some hydropower industrial facilities to completely shut down. An ice dam is a blockage from the movement of a glacier which may produce a proglacial lake. Heavy ice flows in rivers can also damage vessels and require the use of an icebreaker vessel to keep navigation possible.

Ice discs are circular formations of ice floating on river water. They form within eddy currents, and their position results in asymmetric melting, which makes them continuously rotate at a low speed.

On lakes
Ice forms on calm water from the shores, a thin layer spreading across the surface, and then downward. Ice on lakes is generally four types: primary, secondary, superimposed and agglomerate. Primary ice forms first. Secondary ice forms below the primary ice in a direction parallel to the direction of the heat flow. Superimposed ice forms on top of the ice surface from rain or water which seeps up through cracks in the ice which often settles when loaded with snow. An ice shove occurs when ice movement, caused by ice expansion and/or wind action, occurs to the extent that ice pushes onto the shores of lakes, often displacing sediment that makes up the shoreline.

Shelf ice is formed when floating pieces of ice are driven by the wind piling up on the windward shore. This kind of ice may contain large air pockets under a thin surface layer, which makes it particularly hazardous to walk across it. Another dangerous form of rotten ice to traverse on foot is candle ice, which develops in columns perpendicular to the surface of a lake. Because it lacks a firm horizontal structure, a person who has fallen through has nothing to hold onto to pull themselves out.

Snow and freezing rain
Snow crystals form when tiny supercooled cloud droplets (about 10 μm in diameter) freeze. These droplets are able to remain liquid at temperatures lower than -18 C, because to freeze, a few molecules in the droplet need to get together by chance to form an arrangement similar to that in an ice lattice; then the droplet freezes around this "nucleus". Experiments show that this "homogeneous" nucleation of cloud droplets only occurs at temperatures lower than -35 C. In warmer clouds an aerosol particle or "ice nucleus" must be present in (or in contact with) the droplet to act as a nucleus. Our understanding of what particles make efficient ice nuclei is poor – what we do know is they are very rare compared to that cloud condensation nuclei on which liquid droplets form. Clays, desert dust and biological particles may be effective, although to what extent is unclear. Artificial nuclei are used in cloud seeding. The droplet then grows by condensation of water vapor onto the ice surfaces.

Ice storm is a type of winter storm characterized by freezing rain, which produces a glaze of ice on surfaces, including roads and power lines. In the United States, a quarter of winter weather events produce glaze ice, and utilities need to be prepared to minimize damages.

Hard forms
Hail forms in storm clouds when supercooled water droplets freeze on contact with condensation nuclei, such as dust or dirt. The storm's updraft blows the hailstones to the upper part of the cloud. The updraft dissipates and the hailstones fall down, back into the updraft, and are lifted up again. Hail has a diameter of 5 mm or more. Within METAR code, GR is used to indicate larger hail, of a diameter of at least 6.4 mm and GS for smaller. Stones of 0.75 in, 1.0 in and 1.75 in are the most frequently reported hail sizes in North America. Hailstones can grow to 15 cm and weigh more than 0.5 kg. In large hailstones, latent heat released by further freezing may melt the outer shell of the hailstone. The hailstone then may undergo 'wet growth', where the liquid outer shell collects other smaller hailstones. The hailstone gains an ice layer and grows increasingly larger with each ascent. Once a hailstone becomes too heavy to be supported by the storm's updraft, it falls from the cloud. Hail forms in strong thunderstorm clouds, particularly those with intense updrafts, high liquid water content, great vertical extent, large water droplets, and where a good portion of the cloud layer is below freezing 0 C. Hail-producing clouds are often identifiable by their green coloration. The growth rate is maximized at about -13 C, and becomes vanishingly small much below -30 C as supercooled water droplets become rare. For this reason, hail is most common within continental interiors of the mid-latitudes, as hail formation is considerably more likely when the freezing level is below the altitude of 11000 ft. Entrainment of dry air into strong thunderstorms over continents can increase the frequency of hail by promoting evaporative cooling which lowers the freezing level of thunderstorm clouds giving hail a larger volume to grow in. Accordingly, hail is actually less common in the tropics despite a much higher frequency of thunderstorms than in the mid-latitudes because the atmosphere over the tropics tends to be warmer over a much greater depth. Hail in the tropics occurs mainly at higher elevations. Ice pellets (METAR code PL ) are a form of precipitation consisting of small, translucent balls of ice, which are usually smaller than hailstones. This form of precipitation is also referred to as "sleet" by the United States National Weather Service. (In British English "sleet" refers to a mixture of rain and snow.) Ice pellets typically form alongside freezing rain, when a wet warm front ends up between colder and drier atmospheric layers. There, raindrops would both freeze and shrink in size due to evaporative cooling. So-called snow pellets, or graupel, form when multiple water droplets freeze onto snowflakes until a soft ball-like shape is formed. So-called "diamond dust", (METAR code IC ) also known as ice needles or ice crystals, forms at temperatures approaching -40 C due to air with slightly higher moisture from aloft mixing with colder, surface-based air.

On surfaces
As water drips and re-freezes, it can form hanging icicles, or stalagmite-like structures on the ground. On sloped roofs, buildup of ice can produce an ice dam, which stops melt water from draining properly and potentially leads to damaging leaks. More generally, water vapor depositing onto surfaces due to high relative humidity and then freezing results in various forms of atmospheric icing, or frost. Inside buildings, this can be seen as ice on the surface of un-insulated windows. Hoar frost is common in the environment, particularly in the low-lying areas such as valleys. In Antarctica, the temperatures can be so low that electrostatic attraction is increased to the point hoarfrost on snow sticks together when blown by wind into tumbleweed-like balls known as yukimarimo.

Sometimes, drops of water crystallize on cold objects as rime instead of glaze. Soft rime has a density between a quarter and two thirds that of pure ice, due to a high proportion of trapped air, which also makes soft rime appear white. Hard rime is denser, more transparent, and more likely to appear on ships and aircraft. Cold wind specifically causes what is known as advection frost when it collides with objects. When it occurs on plants, it often causes damage to them. Various methods exist to protect agricultural crops from frost - from simply covering them to using wind machines. In recent decades, irrigation sprinklers have been calibrated to spray just enough water to preemptively create a layer of ice that would form slowly and so avoid a sudden temperature shock to the plant, and not be so thick as to cause damage with its weight.

Ablation

Ablation of ice refers to both its melting and its dissolution.

The melting of ice entails the breaking of hydrogen bonds between the water molecules. The ordering of the molecules in the solid breaks down to a less ordered state and the solid melts to become a liquid. This is achieved by increasing the internal energy of the ice beyond the melting point. When ice melts it absorbs as much energy as would be required to heat an equivalent amount of water by 80 °C. While melting, the temperature of the ice surface remains constant at 0 °C. The rate of the melting process depends on the efficiency of the energy exchange process. An ice surface in fresh water melts solely by free convection with a rate that depends linearly on the water temperature, T∞, when T∞ is less than 3.98 °C, and superlinearly when T∞ is equal to or greater than 3.98 °C, with the rate being proportional to (T∞ − 3.98 °C)α, with α = $2$ for T∞ much greater than 8 °C, and α = $1⁄273.16$ for in between temperatures T∞.

In salty ambient conditions, dissolution rather than melting often causes the ablation of ice. For example, the temperature of the Arctic Ocean is generally below the melting point of ablating sea ice. The phase transition from solid to liquid is achieved by mixing salt and water molecules, similar to the dissolution of sugar in water, even though the water temperature is far below the melting point of the sugar. However, the dissolution rate is limited by salt concentration and is therefore slower than melting.

Cooling

Ice has long been valued as a means of cooling. In 400 BC Iran, Persian engineers had already developed techniques for ice storage in the desert through the summer months. During the winter, ice was transported from harvesting pools and nearby mountains in large quantities to be stored in specially designed, naturally cooled refrigerators, called yakhchal (meaning ice storage). Yakhchals were large underground spaces (up to 5000 m3) that had thick walls (at least two meters at the base) made of a specific type of mortar called sarooj made from sand, clay, egg whites, lime, goat hair, and ash. The mortar was resistant to heat transfer, helping to keep the ice cool enough not to melt; it was also impenetrable by water. Yakhchals often included a qanat and a system of windcatchers that could lower internal temperatures to frigid levels, even during the heat of the summer. One use for the ice was to create chilled treats for royalty.

Harvesting
There were thriving industries in 16th–17th century England whereby low-lying areas along the Thames Estuary were flooded during the winter, and ice harvested in carts and stored inter-seasonally in insulated wooden houses as a provision to an icehouse often located in large country houses, and widely used to keep fish fresh when caught in distant waters. This was allegedly copied by an Englishman who had seen the same activity in China. Ice was imported into England from Norway on a considerable scale as early as 1823.

In the United States, the first cargo of ice was sent from New York City to Charleston, South Carolina, in 1799, and by the first half of the 19th century, ice harvesting had become a big business. Frederic Tudor, who became known as the "Ice King", worked on developing better insulation products for long distance shipments of ice, especially to the tropics; this became known as the ice trade.

Between 1812 and 1822, under Lloyd Hesketh Bamford Hesketh's instruction, Gwrych Castle was built with 18 large towers, one of those towers is called the 'Ice Tower'. Its sole purpose was to store Ice.

Trieste sent ice to Egypt, Corfu, and Zante; Switzerland, to France; and Germany sometimes was supplied from Bavarian lakes. From 1930s and up until 1994, the Hungarian Parliament building used ice harvested in the winter from Lake Balaton for air conditioning.

Ice houses were used to store ice formed in the winter, to make ice available all year long, and an early type of refrigerator known as an icebox was cooled using a block of ice placed inside it. Many cities had a regular ice delivery service during the summer. The advent of artificial refrigeration technology made the delivery of ice obsolete.

Ice is still harvested for ice and snow sculpture events. For example, a swing saw is used to get ice for the Harbin International Ice and Snow Sculpture Festival each year from the frozen surface of the Songhua River.

Artificial production
The earliest known written process to artificially make ice is by the 13th-century writings of Arab historian Ibn Abu Usaybia in his book Kitab Uyun al-anba fi tabaqat-al-atibba concerning medicine in which Ibn Abu Usaybi’a attributes the process to an even older author, Ibn Bakhtawayhi, of whom nothing is known.

Ice is now produced on an industrial scale, for uses including food storage and processing, chemical manufacturing, concrete mixing and curing, and consumer or packaged ice. Most commercial icemakers produce three basic types of fragmentary ice: flake, tubular and plate, using a variety of techniques. Large batch ice makers can produce up to 75 tons of ice per day. In 2002, there were 426 commercial ice-making companies in the United States, with a combined value of shipments of $595,487,000. Home refrigerators can also make ice with a built in icemaker, which will typically make ice cubes or crushed ice. The first such device was presented in 1965 by Frigidaire.

Land travel
Ice forming on roads is a common winter hazard, and black ice particularly dangerous because it is very difficult to see. It is both very transparent, and often forms specifically in shaded (and therefore cooler and darker) areas, i.e. beneath overpasses.

Whenever there is freezing rain or snow which occurs at a temperature near the melting point, it is common for ice to build up on the windows of vehicles. Often, snow melts, re-freezes, and forms a fragmented layer of ice which effectively "glues" snow to the window. In this case, the frozen mass is commonly removed with ice scrapers. A thin layer of ice crystals can also form on the inside surface of car windows during sufficiently cold weather. In the 1970s and 1980s, some vehicles such as Ford Thunderbird could be upgraded with heated windshields as the result. This technology fell out of style as it was too expensive and prone to damage, but rear-window defrosters are cheaper to maintain and so are more widespread.

In sufficiently cold places, the layers of ice on water surfaces can get thick enough for ice roads to be built. Some regulations specify that the minimum safe thickness is 4 in for a person, 7 in for a snowmobile and 15 in for an automobile lighter than 5 tonnes. For trucks, effective thickness varies with load - i.e. a vehicle with 9-ton total weight requires a thickness of 20 in. Notably, the speed limit for a vehicle moving at a road which meets its minimum safe thickness is 25 km/h (15 mph), going up to 35 km/h (25 mph) if the road's thickness is 2 or more times larger than the minimum safe value. There is a known instance where a railroad has been built on ice.

The most famous ice road had been the Road of Life across Lake Ladoga. It operated in the winters of 1941–1942 and 1942–1943, when it was the only land route available to the Soviet Union to relieve the Siege of Leningrad by the German Army Group North. The trucks moved hundreds of thousands tonnes of supplies into the city, and hundreds of thousands of civilians were evacuated. It is now a World Heritage Site.

Water-borne travel
For ships, ice presents two distinct hazards. Firstly, spray and freezing rain can produce an ice build-up on the superstructure of a vessel sufficient to make it unstable, potentially to the point of capsizing. Earlier, crewmembers were regularly forced to manually hack off ice build-up. After 1980s, spraying de-icing chemicals or melting the ice through hot water/steam hoses became more common. Secondly, icebergs – large masses of ice floating in water (typically created when glaciers reach the sea) – can be dangerous if struck by a ship when underway. Icebergs have been responsible for the sinking of many ships, the most famous being the Titanic.

For harbors near the poles, being ice-free, ideally all year long, is an important advantage. Examples are Murmansk (Russia), Petsamo (Russia, formerly Finland), and Vardø (Norway). Harbors which are not ice-free are opened up using specialized vessels, called icebreakers. Icebreakers are also used to open routes through the sea ice for other vessels, as the only alternative is to find the openings called "polynyas" or "leads". A widespread production of icebreakers began during the 19th century. Earlier designs simply had reinforced bows in a spoon-like or diagonal shape to effectively crush the ice. Later designs attached a forward propeller underneath the protruding bow, as the typical rear propellers were incapable of effectively steering the ship through the ice

Air travel
For aircraft, ice can cause a number of dangers. As an aircraft climbs, it passes through air layers of different temperature and humidity, some of which may be conducive to ice formation. If ice forms on the wings or control surfaces, this may adversely affect the flying qualities of the aircraft. In 1919, during the first non-stop flight across the Atlantic, the British aviators Captain John Alcock and Lieutenant Arthur Whitten Brown encountered such icing conditions – Brown left the cockpit and climbed onto the wing several times to remove ice which was covering the engine air intakes of the Vickers Vimy aircraft they were flying.

One vulnerability effected by icing that is associated with reciprocating internal combustion engines is the carburetor. As air is sucked through the carburetor into the engine, the local air pressure is lowered, which causes adiabatic cooling. Thus, in humid near-freezing conditions, the carburetor will be colder, and tend to ice up. This will block the supply of air to the engine, and cause it to fail. Between 1969 and 1975, 468 such instances were recorded, causing 75 aircraft losses, 44 fatalities and 202 serious injuries. Thus, carburetor air intake heaters were developed. Further, reciprocating engines with fuel injection do not require carburetors in the first place.

Jet engines do not experience carb icing, but they can be affected by the moisture inherently present in jet fuel freezing and forming ice crystals, which can potentially clog up fuel intake to the engine. Fuel heaters and/or de-icing additives are used to address the issue.

Recreation and sports

Ice plays a central role in winter recreation and in many sports such as ice skating, tour skating, ice hockey, bandy, ice fishing, ice climbing, curling, broomball and sled racing on bobsled, luge and skeleton. Many of the different sports played on ice get international attention every four years during the Winter Olympic Games.

Small boat-like craft can be mounted on blades and be driven across the ice by sails. This sport is known as ice yachting, and it had been practiced for centuries. Another vehicular sport is ice racing, where drivers must speed on lake ice, while also controlling the skid of their vehicle (similar in some ways to dirt track racing). The sport has even been modified for ice rinks.

As thermal ballast

 * Ice is still used to cool and preserve food in portable coolers.
 * Ice cubes or crushed ice can be used to cool drinks. As the ice melts, it absorbs heat and keeps the drink near 0 C.
 * Ice can be used as part of an air conditioning system, using battery- or solar-powered fans to blow hot air over the ice. This is especially useful during heat waves when power is out and standard (electrically powered) air conditioners do not work.
 * Ice can be used (like other cold packs) to reduce swelling (by decreasing blood flow) and pain by pressing it against an area of the body.

As structural material

 * Engineers used the substantial strength of pack ice when they constructed Antarctica's first floating ice pier in 1973. Such ice piers are used during cargo operations to load and offload ships. Fleet operations personnel make the floating pier during the winter. They build upon naturally occurring frozen seawater in McMurdo Sound until the dock reaches a depth of about 22 ft. Ice piers are inherently temporary structures, although some can last as long as 10 years. Once a pier is no longer usable, it is towed to sea with an icebreaker.
 * Structures and ice sculptures are built out of large chunks of ice or by spraying water The structures are mostly ornamental (as in the case with ice castles), and not practical for long-term habitation. Ice hotels exist on a seasonal basis in a few cold areas. Igloos are another example of a temporary structure, made primarily from snow.
 * Engineers can also use ice to destroy. In mining, drilling holes in rock structures and then pouring water during cold weather is an accepted alternative to using dynamite, as the rock cracks when the water expands as ice.
 * During World War II, Project Habbakuk was an Allied programme which investigated the use of pykrete (wood fibers mixed with ice) as a possible material for warships, especially aircraft carriers, due to the ease with which a vessel immune to torpedoes, and a large deck, could be constructed by ice. A small-scale prototype was built, but it soon turned out the project would cost far more than a conventional aircraft carrier while being many times slower and also vulnerable to melting.
 * Ice has even been used as the material for a variety of musical instruments, for example by percussionist Terje Isungset.

Historical

Greenhouse gas emissions from human activities unbalance the Earth's energy budget and so cause an accumulation of heat. About 90% of that heat is added to ocean heat content, 1% is retained in the atmosphere and 3-4% goes to melt major parts of the cryosphere. Between 1994 and 2017, 28 trillion tonnes of ice were lost around the globe as the result. Arctic sea ice decline accounted for the single largest loss (7.6 trillion tonnes), followed by the melting of Antarctica's ice shelves (6.5 trillion tonnes), the retreat of mountain glaciers (6.1 trillion tonnes), the melting of the Greenland ice sheet (3.8 trillion tonnes) and finally the melting of the Antarctic ice sheet (2.5 trillion tonnes) and the limited losses of the sea ice in the Southern Ocean (0.9 trillion tonnes).

Other than the sea ice (which already displaces water due to Archimedes' principle), these losses are a major cause of sea level rise (SLR) and they are expected to intensify in the future. In particular, the melting of the West Antarctic ice sheet may accelerate substantially as the floating ice shelves are lost and can no longer buttress the glaciers. This would trigger poorly understood marine ice sheet instability processes, which could then increase the SLR expected for the end of the century (between 30 cm and 1 m, depending on future warming), by tens of centimeters more.

Ice loss in Greenland and Antarctica also produces large quantities of fresh meltwater, which disrupts the Atlantic meridional overturning circulation (AMOC) and the Southern Ocean overturning circulation, respectively. These two halves of the thermohaline circulation are very important for the global climate. A continuation of high meltwater flows may cause a severe disruption (up to a point of a "collapse") of either circulation, or even both of them. Either event would be considered an example of tipping points in the climate system, because it would be extremely difficult to reverse. AMOC is generally not expected to collapse during the 21st century, while there is only limited knowledge about the Southern Ocean circulation.

Another example of ice-related tipping point is permafrost thaw. While the organic content in the permafrost causes and methane emissions once it thaws and begins to decompose, ice melting liqufies the ground, causing anything built above the former permafrost to collapse. By 2050, the economic damages from such infrastructure loss are expected to cost tens of billions of dollars.

Predictions

In the future, the Arctic Ocean is likely to lose effectively all of its sea ice during at least some Septembers (the end of the ice melting season), although some of the ice would refreeze during the winter. I.e. an ice-free September is likely to occur once in every 40 years if global warming is at 1.5 C-change, but would occur once in every 8 years at 2 C-change and once in every 1.5 years at 3 C-change. This would affect the regional and global climate due to the ice-albedo feedback. Because ice is highly reflective of solar energy, persistent sea ice cover lowers local temperatures. Once that ice cover melts, the darker ocean waters begin to absorb more heat, which also helps to melt the remaining ice.

Global losses of sea ice between 1992 and 2018, almost all of them in the Arctic, have already had the same impact as 10% of greenhouse gas emissions over the same period. If all the Arctic sea ice was gone every year between June and September (polar day, when the Sun is constantly shining), temperatures in the Arctic would increase by over 1.5 C-change, while the global temperatures would increase by around 0.19 C-change.

By 2100, at least a quarter of mountain glaciers outside of Greenland and Antarctica would melt, and effectively all ice caps on non-polar mountains are likely to be lost around 200 years after global warming reaches 2 C-change. The West Antarctic ice sheet is highly vulnerable and will likely disappear even if the warming does not progress further,  although it could take around 2,000 years before its loss is complete. The Greenland ice sheet will most likely be lost with the sustained warming between 1.7 C-change and 2.3 C-change, although its total loss requires around 10,000 years. Finally, the East Antarctic ice sheet will take at least 10,000 years to melt entirely, which requires a warming of between 5 C-change and 10 C-change.

If all the ice on Earth melted, it would result in about 70 m of sea level rise, with some 53.3 m coming from East Antarctica. Due to isostatic rebound, the ice-free land would eventually become 301 m higher in Greenland and 494 m in Antarctica, on average. Areas in the center of each landmass would become up to 783 m and 936 m higher, respectively. The impact on global temperatures from losing West Antartica, mountain glaciers and the Greenland ice sheet is estimated at 0.05 C-change, 0.08 C-change and 0.13 C-change, respectively, while the lack of the East Antarctic ice sheet would increase the temperatures by 0.6 C-change.

Non-water
The solid phases of several other volatile substances are also referred to as ices; generally a volatile is classed as an ice if its melting or sublimation point lies above or around 100 K (assuming standard atmospheric pressure). The best known example is dry ice, the solid form of carbon dioxide. Its sublimation/deposition point occurs at 194.7 K.

A "magnetic analogue" of ice is also realized in some insulating magnetic materials in which the magnetic moments mimic the position of protons in water ice and obey energetic constraints similar to the Bernal-Fowler ice rules arising from the geometrical frustration of the proton configuration in water ice. These materials are called spin ice.

title: Ice