This allowed Allègre and his team to develop new ideas about the age and chemical evolution of the outer parts of the Earth, and also provide new information and insight into the early history of the solar system, by dating meteorites.

This combined data from isotope geochemistry with constraints from geophysics to develop ideas about the long-term chemical evolution of the planet, from core-formation to crustal growth.

This led to the establishment of the annual 'Goldschmidt Conferences' of the international geochemistry community, in cooperation with the Geochemical Society which are held in alternate years in Europe, and in the United States.

[21] In 1976, Allègre and volcanologist Haroun Tazieff became involved in an intense and public quarrel about whether inhabitants should evacuate the areas surrounding the la Soufrière volcano on the Caribbean island of Guadeloupe, which had begun to show signs of unrest, including steam explosions.

[23] A one time member of the French Socialist Party, Allègre is better known to the general public for his political responsibilities, which included serving as Minister of Education of France in the Jospin cabinet from 4 June 1997 to March 2000, when he was replaced by Jack Lang.

[24][25] In 1996, Allegre published La Défaite de Platon ("The defeat of Plato"), described by mathematician Pierre Schapira in the Spring 1997 edition of Mathematical Intelligencer as "one of the most savage broadsides against conceptual thought.

"[26] In the run-up to the 2007 French presidential election, he endorsed Lionel Jospin, then Dominique Strauss-Kahn, for the Socialist nomination, and finally sided with the ex-Socialist Jean-Pierre Chevènement, against Ségolène Royal.

When Chevènement decided not to run, he publicly declined to support Royal's bid for the presidency, citing differences over nuclear energy, GMOs and stem-cell research.

[28] This represented a change of mind, since Allègre wrote in 1987 that "By burning fossil fuels, man increased the concentration of carbon dioxide in the atmosphere which, for example, has raised the global mean temperature by half a degree in the last century".

[29] Allègre accused those agreeing with the mainstream scientific view of global warming of being motivated by money, saying that "the ecology of helpless protesting has become a very lucrative business for some people!

"[30] In 2009, when it was suggested that Claude Allègre might be offered a position as minister in President Nicolas Sarkozy's government, TV presenter and environmental activist Nicolas Hulot stated: In a 2010 petition, more than 500 French researchers asked Science Minister Valérie Pécresse to dismiss Allègre's book L'imposture climatique, claiming the book was "full of factual mistakes, distortions of data, and plain lies".