Contents

Preface viii

Acknowledgments xii

Introduction xiv

The Science of Paleoclimatology 1

The Purpose of Paleoclimatology 2

What Prehistoric Change Reveals about the Future 7

Rate of Change 8

Climate Patterns 12

Key Climate Intervals in the Earth's Past 16

The Earth's Geologic Past 17

Ancient Climates—2 Million to 4.6 Billion Years Ago 22

Evidence for Snowball Earth 29 The Pleistocene Climates—10,000 Years to 2 Million

Years Ago 32 The Holocene/Recent Climates—10,000 Years Ago to Present 35

Climate Time Line at a Glance 39

Key Uncertainties 40

Geochronology and Climate Proxies 42

Radiometric Dating Techniques 42

The Discovery and Use of Radioactive Decay 45

Nonradiogenic Dating Methods 53

Climate Reconstruction Resolution Climate Proxies

54 56

4 Proxy Data: Geomorphic Landforms 58

Geologic Evidence 60

Landforms of Arid Environments 61

Landforms of Cold Environments 69

Geological and Geochemical Proxy Data 73

Soils and Mineralogy Composition 75

Sediments 79

Ice Cores 85

Loess 90

Cave Environments 92

6 Biotic Proxies 96

Life-forms/Fossils 97

Dendrochronology 103 A. E. Douglass (1867-1962): The Birth of

Dendrochronology 108

Coral 108

Vegetation 111

Climate Change and Past Civilizations 115

The Rise of Civilization 116

Central and North America 117

Middle East, Far East, and Europe 124

Adaptations Today 127

8 Using New Technology to Discover the Past 131

The Science of Remote Sensing 131

The Science of Geographic Information Systems 139

9 What the Experts Say 143

Modeling Abrupt Climate Change 143

Mineral Clues to Past Climate 146

The Stories Marshes Tell 147

World Warmth Edging Ancient Levels 149

10 Conclusions and a Glance into the Future 152

Modeling the Earth's Climate 152

What Some Models Say about North America 157

Pangaea Ultima—the Future? 161

The Geological Timescale 166

The Periodic Table of the Elements 167

Chronology 169

Glossary 175

Further Resources 181

Index 188

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