solar irradiation (1904) by the German mathematician, Ludwig Pilgrim (1879–1935). It was
Joseph John Murphy (1827–1894), however, who, as early as 1869, proposed that cool
summers of the northern hemisphere had instigated the ice ages. This original idea was taken
up in 1921 by the German paleoclimatologist Rudolf Spitaler (1859–1946), but was popularized by the Serbian geophysicist engineer, Milutin Milankovich (1879–1958), mainly
through his books Mathematical Theory of Thermal Phenomena Produced by Solar Radiation
(1920) and Kanon der Erdbestrahlung und seine Anwendung auf des Eizeitenproblem (1941).
Milankovitch was a contemporary of the German geophysicist Alfred Wegener (1880–1930)
with whom he became acquainted through the Russsian-born climatologist Wladimir Köppen
(1846–1940), Wegener’s father-in-law (Thiede, 2017). The modern era of astronomical theory
was born, even if there remained much criticism related to the lack of reliable paleoclimatic
data and of a reliable timescale, both by geologists and meteorologists. It was not until the
1950s and 1960s that new techniques made it possible to date, measure, and interpret the
climate records contained in marine sediments, in ice and on land. In 1955, the American,
Cesare Emiliani (1922–1995), proposed a stratigraphy, which still applies today, based on the
succession of minima and maxima of the oxygen-18 / oxygen-16 isotopic ratio measured in
the foraminiferal shells found in sediments taken from the deep ocean. The interpretation of
this isotopic ratio in terms of salinity was made by Jean-Claude Duplessy (1970), and in terms
of temperature and volume of ice (1973) by Nicholas Shackleton (1937–2006) and Niels
Opdyke (1933–2019). Mathematical tools made it possible to establish transfer functions to
quantitatively interpret information collected in the oceans in 1974 by the American paleoceanographers John Imbrie (1925–2016) and Nilva Kipp (1925–1989),) and in tree rings
(Harold Fritts, 1968). Efforts by the CLIMAP group (1976) resulted in the first seasonal
climate chart of the Last Glacial Maximum and the pivotal article by James Hays, John Imbrie,
and Nicholas Shackleton (1976). The arrival of big computers allowed the first climate simulations to be conducted using general circulation models (Fred Nelson Alyea, 1972), and
further astronomical calculations led to the establishment of a high-precision time scale reference, as well as the determination of the daily and seasonal irradiation essential for climate
modeling (André Berger, 1973 and Berger and Loutre, 1991).These calculations of the
astronomical parameters were based on the 1974 and 1988 developments of the orbital elements by the French astronomers Pierre Bretagnon (1942–2002) and Jacques Laskar,
respectively. These are valid over a few million years. The Laskar solution was extended over
a few tens of millions of years by Laskar et al. (2011) and over the whole Mesozoic with the
American paleobiologist Paul Olsen and colleagues (2019).
This evolution and the recent advances in paleoclimatology show the difficulties involved
in tackling the study of the climate system. Overcoming these difficulties requires high-quality
books to improve understanding and to update the range of disciplines involved. It is with this
perspective in mind that this book was written. Written originally in French, it unquestionably
fills a gap in the field of graduate and postgraduate third-level education that goes far beyond
its description. It provides an overview of the state of knowledge on a number of key topics by
outlining the information necessary to understand and appreciate the complexity of the disciplines discussed, making it a reference book on the subject. The first of the two volumes is
devoted to the methods used to reconstruct ancient climates, the second to the behavior of the
climate system in the past. Many of the thirty-one chapters are written by researchers from the
Laboratoire des Sciences du Climat et de l’Environnement and associated research laboratories each focusing on his or her area of expertise, which ensures a reliable document founded
on solid experience.
Understanding the evolving climate of the Earth and its many variations is not just an
academic challenge. It is also fundamental in order to better understand the future climate and
its possible impacts on the society of tomorrow. Jean-Claude Duplessy and Gilles Ramstein
have achieved this huge feat by bringing together fifty or so of the most highly reputed
researchers in the field.
Foreword
vii
Joseph John Murphy (1827–1894), however, who, as early as 1869, proposed that cool
summers of the northern hemisphere had instigated the ice ages. This original idea was taken
up in 1921 by the German paleoclimatologist Rudolf Spitaler (1859–1946), but was popularized by the Serbian geophysicist engineer, Milutin Milankovich (1879–1958), mainly
through his books Mathematical Theory of Thermal Phenomena Produced by Solar Radiation
(1920) and Kanon der Erdbestrahlung und seine Anwendung auf des Eizeitenproblem (1941).
Milankovitch was a contemporary of the German geophysicist Alfred Wegener (1880–1930)
with whom he became acquainted through the Russsian-born climatologist Wladimir Köppen
(1846–1940), Wegener’s father-in-law (Thiede, 2017). The modern era of astronomical theory
was born, even if there remained much criticism related to the lack of reliable paleoclimatic
data and of a reliable timescale, both by geologists and meteorologists. It was not until the
1950s and 1960s that new techniques made it possible to date, measure, and interpret the
climate records contained in marine sediments, in ice and on land. In 1955, the American,
Cesare Emiliani (1922–1995), proposed a stratigraphy, which still applies today, based on the
succession of minima and maxima of the oxygen-18 / oxygen-16 isotopic ratio measured in
the foraminiferal shells found in sediments taken from the deep ocean. The interpretation of
this isotopic ratio in terms of salinity was made by Jean-Claude Duplessy (1970), and in terms
of temperature and volume of ice (1973) by Nicholas Shackleton (1937–2006) and Niels
Opdyke (1933–2019). Mathematical tools made it possible to establish transfer functions to
quantitatively interpret information collected in the oceans in 1974 by the American paleoceanographers John Imbrie (1925–2016) and Nilva Kipp (1925–1989),) and in tree rings
(Harold Fritts, 1968). Efforts by the CLIMAP group (1976) resulted in the first seasonal
climate chart of the Last Glacial Maximum and the pivotal article by James Hays, John Imbrie,
and Nicholas Shackleton (1976). The arrival of big computers allowed the first climate simulations to be conducted using general circulation models (Fred Nelson Alyea, 1972), and
further astronomical calculations led to the establishment of a high-precision time scale reference, as well as the determination of the daily and seasonal irradiation essential for climate
modeling (André Berger, 1973 and Berger and Loutre, 1991).These calculations of the
astronomical parameters were based on the 1974 and 1988 developments of the orbital elements by the French astronomers Pierre Bretagnon (1942–2002) and Jacques Laskar,
respectively. These are valid over a few million years. The Laskar solution was extended over
a few tens of millions of years by Laskar et al. (2011) and over the whole Mesozoic with the
American paleobiologist Paul Olsen and colleagues (2019).
This evolution and the recent advances in paleoclimatology show the difficulties involved
in tackling the study of the climate system. Overcoming these difficulties requires high-quality
books to improve understanding and to update the range of disciplines involved. It is with this
perspective in mind that this book was written. Written originally in French, it unquestionably
fills a gap in the field of graduate and postgraduate third-level education that goes far beyond
its description. It provides an overview of the state of knowledge on a number of key topics by
outlining the information necessary to understand and appreciate the complexity of the disciplines discussed, making it a reference book on the subject. The first of the two volumes is
devoted to the methods used to reconstruct ancient climates, the second to the behavior of the
climate system in the past. Many of the thirty-one chapters are written by researchers from the
Laboratoire des Sciences du Climat et de l’Environnement and associated research laboratories each focusing on his or her area of expertise, which ensures a reliable document founded
on solid experience.
Understanding the evolving climate of the Earth and its many variations is not just an
academic challenge. It is also fundamental in order to better understand the future climate and
its possible impacts on the society of tomorrow. Jean-Claude Duplessy and Gilles Ramstein
have achieved this huge feat by bringing together fifty or so of the most highly reputed
researchers in the field.
Foreword
vii