For several years, Philippe was director of research unit EPOC, after which he supervised the research carried out by CNRS in the fields of ocean, atmosphere and climate (around 30 research units and observatories), which further strengthened his interdisciplinary background. It also reinforced his wish to link information from several disciplines to analyze the dynamic complexity and evolution of the Earth System over 4.6 billion years.


He is a dedicated amateur photographer of the natural environment.

Philippe Bertrand

Philippe Bertrand is physical chemist. He conducted his research career at CNRS (Centre National de la Recherche Scientifique, the main French research organization). His main research topics are paleoceanography and paleoclimatology.


His research has focused on the relationships between the activity of coastal upwellings systems and climatic variations in the last glacial-interglacial cycles. He then became interested in the functioning of the Earth System as a whole, and devoted to this topic his book Les attracteurs de Gaia and many other publications.

Philippe Bertrand in Reunion Island

Philippe (first on the left) with his wife Marie-Soline and the team of the Reunion Island Atmospheric Physics Observatory (Maïdo, 2160 m) in 2014.

Louis Legendre

Louis Legendre conducted his career in Canada and France. He is professor emeritus at Sorbonne University, France, and Laval University, Canada. He conducts his research at the Villefranche Oceanography Laboratory, on the shores of the Mediterranean Sea.

His fields of research are: marine biogeochemistry, biological oceanography, numerical ecology, and philosophy of science. His work is a blend of theoretical studies, laboratory research, and fieldwork. He tested his theoretical contributions by conducting research in tropical, temperate and polar waters, including the Gulf of St. Lawrence, Arctic waters and polynyas, the Greenland Sea, the Mediterranean Sea, lagoons of coral reefs and atolls of French Polynesia, the Sea of Okhotsk, the Equatorial Atlantic, and lakes.

Louis received several prestigious honours and awards, including membership in four academies of science in Canada (RSC), China (CAS) and Europe (AE and EurASc). His textbook Numerical Ecology (with Pierre Legendre) is used for research and university teaching all over the world. His book on Scientific Research and Discovery and its abridged electronic edition are also well known.


He enjoys the cultures, including foods and drinks, of countries where he worked and/or travelled extensively, especially (alphabetical order) China, France, Greece, Italy, Japan, Québec and Spain.

Photo (portrait) of Louis Legendre.

Origin and Development of the Book

The authors of Earth, Our Living Planet, Philippe and Louis, are two oceanographers. Philippe was initially trained as a chemist, and spent most of his career in France. Louis was initially trained as a biologist, and spent the first part of his career in Canada before moving to France. They first met when they were both directors of French oceanographic research units, Philippe on the Atlantic Ocean and Louis on the Mediterranean Sea. Talking together, they realized that they shared a common interest in topics that went beyond their own scientific domains, especially Earth System Science.

Philippe had published a book on the evolution and functioning of the Earth System, and Louis a book on the discovery process. They were interested in each other’s books, and talked about some of the general topics following from their works, including the general lack of analyses in the scientific literature of the conditions that had led organisms and ecosystems to take over the Earth System during the course of the history of the planet.

Hence, their question: “Which combination of factors led to this apparently unique development in the Solar System?” They answer this key question in their book Earth, Our Living Planet.


Philippe and Louis wrote their book for readers who would be fascinated by the interactions between astronomical, geological, environmental, biological phenomena and ecological characteristics of the planet that led to the unique Earth System. Readers of the book include scientifically literate members of the general public, students, and researchers from various scientific and non-scientific disciplines.

Cover of book "Earth, Our Living Planet", 2021, Springer.