The Climate Of Past Interglacials

Historically, climate fluctuations, such as the Little Ice Age, show that interglacial climate chage in not entirely stable, but responds to even subtle changes in radiative forcing. Through research, it has been made clear that even an abrupt change of climate within years is not just a theoretical possibility but has in fact happened in the prehistoric past. It is therefore clear that in principal it could happen again. Human civilaization has exploded under the mild and relatively stable climatic conditions that have prevailed over the last 11,000 years. This book focuses on revisiting the past and to study climate and environment in a suite of experiments where boundary conditions are similar but not identical to today so we can learn about the climate-environment system, its sensitivity, thresholds and feedback. The palaeoclimate community holds an important key to scientific information on climate change that provides a basis for appropriate adaptation and mitigation strategies. The authors of this book have taken up this challenge and summarize their results in this special volume. It presents state-of-the-art science on new reconstructions from all spheres of the Earth System and on their synthesis, on methodological advances, and on the current ability of numerical models to simulate low and high frequency changes of climate, environment, and chemical cycling related to interglacials. * Summarizes important information on climate change, providing a basis for appropriate adaptation and mitigation strategies for human civilization * Reports on new reconstuctions on methodological advances, numerical models simulating low and high frequence changes, and chemical cycling related to interglacials * Incorporates palaeovegetaion and numerical modeling of climate and environmental and geochemical parameters to address regional feedback to global change with successful data-models

This book studies the history and gives an analysis of extreme climate change on Earth. In order to provide a long-term perspective, the first chapter briefly reviews some of the wild gyrations that occurred in the Earth’s climate hundreds of millions of years ago: snowball Earth and hothouse Earth. Coming closer to modern times, the effects of continental drift, particularly the closing of the Isthmus of Panama are believed to have contributed to the advent of ice ages in the past three million years. This first chapter sets the stage for a discussion of ice ages in the geological recent past (i.e. within the last three million years, with an emphasis on the last few hundred thousand years). The second chapter discusses geological evidence for ice ages – how geologists surmised their existence prior to actual subsurface data that proved the theory. The following two chapters look at ice cores (primarily from Greenland and Antarctica). Chapter 3 discusses how ice core data is processed and Chapter 4 summarizes data obtained from ice cores. Chapter 5 discusses the processing of data obtained from ocean sediments, and summarizes the results, while the following chapter discusses data from other sources, such as "Devil’s Cave." Chapter 7 summarizes the experimental results from Chapters 4, 5, and 6. It provides the foundation for comparison with theories in later chapters. In a perfect world, this data would be totally separate and disconnected from theory. Unfortunately, as the author shows, dating of much of the data was accomplished by "tuning" to the astronomical theory, which introduces circular reasoning. Chapter 8 provides a brief overview of the various theories that have been devised to "explain" the patterns of alternating ice ages and interglacials that have occurred over the past three million years. This serves as an introduction to the following three chapters which presents the astronomical theory in its various manifestations, compare the astronomical theory with data, and then compare other theories with data. Finally, Chapter 12 summarizes what we think we know about ice ages and, more importantly, what we don’t know.

Nothing new from the Ice Age? Far from it! Barely ten years have passed since the first edition of this book was published, but in that time researchers around the world have developed new methods and published their findings in scientific journals. Consequently, ideas about the course of the Ice Age have changed dramatically. The sequence of the individual ice advances, the direction of ice movement and the direction of meltwater drainage are only partially known, but they can be reconstructed. This book offers in-depth information about the state of the investigations. Ice ages are the periods of the earth's history in which at least one polar region is glaciated or covered by sea ice. Thus, we are currently living in an Ice Age. The present Ice Age is also the period in which humans started to intervene in the shaping of the earth. The results are obvious. Aerial and satellite images can be used to trace the melting of glaciers, but also the decay of the Arctic permafrost, and the clearing of the Brazilian rainforest. This book is a translation of the original German 2nd edition Das Eiszeitalter by Juergen Ehlers, published by Springer-Verlag GmbH Germany, part of Springer Nature, in 2020. The translation was done with the help of artificial intelligence (machine translation by DeepL.com). A subsequent human revision was done primarily in terms of content, so that the book will read stylistically differently from a conventional translation. Springer Nature works continuously to further the development of tools for the production of books and promotes technologies to support the authors.

Focuses on the mechanisms that caused past climate changes, putting the Earth repeatedly into and out of ice ages.

The work addresses the following questions in the context of interglacial climate dynamics: (i) What are the amplitudes of natural climate variations on timescales of several years to millennia? (ii) Do abrupt changes in the large-scale circulation of the Atlantic Ocean occur in interglacials? (iii) Which biogeochemical feedback mechanisms control the natural limits of atmospheric concentrations of greenhouse gases and aerosols? (iv) Which linkages exist between climate and pre-industrial cultures? The work is based on an integrated approach in paleoclimate research, in which all available paleoclimate archives (terrestrial and marine as well as ice cores) are combined in order to yield a comprehensive and quantitative analysis of global environmental variations. Moreover, through a close linkage be-tween paleoclimate reconstructions and results from Earth-system models detailed insights into the dynamics of climate variations are gained.

The geologic record contains evidence of greenhouse climates in the earth's past, and by studying these past conditions, we can gain greater understanding of the forcing mechanisms and feedbacks that influence today's climate. Leading experts in paleoclimatology combine in one integrated volume new and state-of-the-art paleontological, geological, and theoretical studies to assess intervals of global warmth. The book reviews what is known about the causes and consequences of globally warm climates, demonstrates current directions of research on warm climates, and outlines the central problems that remain unresolved. The chapters present new research on a number of different warm climate intervals from the early Paleozoic to the early Cenozoic. The book will be of great interest to researchers in paleoclimatology, and it will also be useful as a supplementary text on advanced undergraduate or graduate level courses in paleoclimatology and earth science.

There is little dispute within the scientific community that humans are changing Earth's climate on a decadal to century time-scale. By the end of this century, without a reduction in emissions, atmospheric CO2 is projected to increase to levels that Earth has not experienced for more than 30 million years. As greenhouse gas emissions propel Earth toward a warmer climate state, an improved understanding of climate dynamics in warm environments is needed to inform public policy decisions. In Understanding Earth's Deep Past, the National Research Council reports that rocks and sediments that are millions of years old hold clues to how the Earth's future climate would respond in an environment with high levels of atmospheric greenhouse gases. Understanding Earth's Deep Past provides an assessment of both the demonstrated and underdeveloped potential of the deep-time geologic record to inform us about the dynamics of the global climate system. The report describes past climate changes, and discusses potential impacts of high levels of atmospheric greenhouse gases on regional climates, water resources, marine and terrestrial ecosystems, and the cycling of life-sustaining elements. While revealing gaps in scientific knowledge of past climate states, the report highlights a range of high priority research issues with potential for major advances in the scientific understanding of climate processes. This proposed integrated, deep-time climate research program would study how climate responded over Earth's different climate states, examine how climate responds to increased atmospheric carbon dioxide and other greenhouse gases, and clarify the processes that lead to anomalously warm polar and tropical regions and the impact on marine and terrestrial life. In addition to outlining a research agenda, Understanding Earth's Deep Past proposes an implementation strategy that will be an invaluable resource to decision-makers in the field, as well as the research community, advocacy organizations, government agencies, and college professors and students. (National Academies Press website 5/16/2011).