Preface
Before taking this journey together into the Earth’s paleoclimates, it is important to know what
we will be facing. This exploration will bring us into the heart of the ‘Earth system’: a tangle
of interwoven components with very different characteristics and response times, a system in
constant interaction.
The first volume is dedicated (Chaps. 1 and 2) to an introduction to climate of the Earth.
Chapters 3–9 focus on different time measurement and datation technics. The most important
part of this first volume deals with the reconstructions of different climatic parameters from the
three major reservoirs (ocean, continent, cryosphere, Chaps. 10–21). The second volume is
devoted to modeling the Earth system to better understand and simulate its evolution (Chaps. 1
–9). Last but not least, the final chapter (Chap. 10) describes the future climate of the Earth
projection from next century to millennia.
The first part of this book (Chaps. 1 and 2) will equip the reader with a ‘climate kit’ before
delving into the study of paleoclimates. This quick overview shows the great diversity in the
systems involved. From the microphysics of the clouds that can be seen evolving over our
heads by the minute to the huge ice caps that take nearly 100,000 years to reach their peak, the
spatiotemporal differences are dizzying (Chap. 1). Yet, it is the same ‘Earth system’ that,
throughout the ages, undergoes various disturbances that we will address. Chapter 2 takes us
on a journey through the geological history of our planet. The distribution of continents,
oceans, and reliefs changes how energy and heat are transported at the Earth’s surface by the
ocean and the atmosphere.
The study of paleoclimates requires an understanding of two indispensable concepts in
order to describe the past climates of the Earth.
The first is the concept of time. Measuring time is fundamental to our research, and an
understanding of the diversity of temporalities particular to paleoclimatic records is essential.
The second part (Chaps. 3 to 9) of this book is devoted to the question of the measurement of
time. Different techniques may be implemented depending on the timescales considered in
Chap. 3. Thus, although carbon-14 (Chap. 4) provides us with reliable measurements going
back to 30,000–40,000 years ago, other radioactive disequilibria (Chaps. 5 and 6) need to be
used to access longer timescales. But it is not only the radioactivity-based methods that inform
us of the age of sediments; the use of magnetism (Chap. 7) is also a valuable way of placing
events occurring on the geological timescale into the context of climate. On shorter timescales,
the use of tree rings is also a valuable method (Chap. 8). Ice core dating techniques will also be
outlined (Chap. 9). This gamut of different methods shows how researchers have succeeded in
developing ‘paleo-chronometers’ which are essential to locate climate archives within a
temporal context, but also to establish the connections of cause and effect between the different
components of the Earth system during periods of climatic changes.
The second concept is that of climate reconstruction. Indeed, in the same way that there is
no single chronometer that allows us to go back in time, there is not one paleothermometer,
pluviometer, or anemometer. Just as it was necessary to invent paleo-chronometers based on
physical or biological grounds in order to attribute an age and an estimate of its uncertainty to
archives, the relevant climatic indicators had to be invented to quantify the variations in
temperature, hydrological cycle, and deepwater current. The third part of this book (Chaps. 10
xv
Before taking this journey together into the Earth’s paleoclimates, it is important to know what
we will be facing. This exploration will bring us into the heart of the ‘Earth system’: a tangle
of interwoven components with very different characteristics and response times, a system in
constant interaction.
The first volume is dedicated (Chaps. 1 and 2) to an introduction to climate of the Earth.
Chapters 3–9 focus on different time measurement and datation technics. The most important
part of this first volume deals with the reconstructions of different climatic parameters from the
three major reservoirs (ocean, continent, cryosphere, Chaps. 10–21). The second volume is
devoted to modeling the Earth system to better understand and simulate its evolution (Chaps. 1
–9). Last but not least, the final chapter (Chap. 10) describes the future climate of the Earth
projection from next century to millennia.
The first part of this book (Chaps. 1 and 2) will equip the reader with a ‘climate kit’ before
delving into the study of paleoclimates. This quick overview shows the great diversity in the
systems involved. From the microphysics of the clouds that can be seen evolving over our
heads by the minute to the huge ice caps that take nearly 100,000 years to reach their peak, the
spatiotemporal differences are dizzying (Chap. 1). Yet, it is the same ‘Earth system’ that,
throughout the ages, undergoes various disturbances that we will address. Chapter 2 takes us
on a journey through the geological history of our planet. The distribution of continents,
oceans, and reliefs changes how energy and heat are transported at the Earth’s surface by the
ocean and the atmosphere.
The study of paleoclimates requires an understanding of two indispensable concepts in
order to describe the past climates of the Earth.
The first is the concept of time. Measuring time is fundamental to our research, and an
understanding of the diversity of temporalities particular to paleoclimatic records is essential.
The second part (Chaps. 3 to 9) of this book is devoted to the question of the measurement of
time. Different techniques may be implemented depending on the timescales considered in
Chap. 3. Thus, although carbon-14 (Chap. 4) provides us with reliable measurements going
back to 30,000–40,000 years ago, other radioactive disequilibria (Chaps. 5 and 6) need to be
used to access longer timescales. But it is not only the radioactivity-based methods that inform
us of the age of sediments; the use of magnetism (Chap. 7) is also a valuable way of placing
events occurring on the geological timescale into the context of climate. On shorter timescales,
the use of tree rings is also a valuable method (Chap. 8). Ice core dating techniques will also be
outlined (Chap. 9). This gamut of different methods shows how researchers have succeeded in
developing ‘paleo-chronometers’ which are essential to locate climate archives within a
temporal context, but also to establish the connections of cause and effect between the different
components of the Earth system during periods of climatic changes.
The second concept is that of climate reconstruction. Indeed, in the same way that there is
no single chronometer that allows us to go back in time, there is not one paleothermometer,
pluviometer, or anemometer. Just as it was necessary to invent paleo-chronometers based on
physical or biological grounds in order to attribute an age and an estimate of its uncertainty to
archives, the relevant climatic indicators had to be invented to quantify the variations in
temperature, hydrological cycle, and deepwater current. The third part of this book (Chaps. 10
xv