There has never been a more critical time for students to understand the record of Earth’s climate history, as well as the relevance of that history to understanding Earth’s present and likely future climate. There also has never been a more critical time for students, as well as the public-at-large, to understand how we know, as much as what we know, in science. This book addresses these needs by placing you, the student, at the center of learning. In this book, you will actively use inquiry-based explorations of authentic scientific data to develop skills that are essential in all disciplines: making observations, developing and testing hypotheses, reaching conclusions based on the available data, recognizing and acknowledging uncertainty in scientific data and scientific conclusions, and communicating your results to others.
The context for understanding global climate change today lies in the records of Earth’s past, as preserved in archives such as sediments and sedimentary rocks on land and on the seafloor, as well as glacial ice, corals, speleothems, and tree rings. These archives have been studied for decades by geoscientists and paleoclimatologists. Much like detectives, these researchers work to reconstruct what happened in the past, as well as when and how it happened, based on the often-incomplete and indirect records of those events preserved in these archives. This book uses guided-inquiry to build your knowledge of foundational concepts needed to interpret such archives. Foundational concepts include: interpreting the environmental meaning of sediment composition, determining ages of geologic materials and events (supported by a new section on radiometric dating), and understanding the role of CO2 in Earth’s climate system, among others. Next, this book provides the opportunity for you to apply your foundational knowledge to a collection of paleoclimate case studies. The case studies consider: long-term climate trends, climate cycles, major and/or abrupt episodes of global climate change, and polar paleoclimates. New sections on sea level change in the past and future, climate change and life, and climate change and civilization expand the book’s examination of the causes and effects of Earth’s climate history.
In using this book, we hope you gain new knowledge, new skills, and greater confidence in making sense of the causes and consequences of climate change. Our goal is that science becomes more accessible to you. Enjoy the challenge and the reward of working with scientific data and results!
Reconstructing Earth’s Climate History, Second Edition, is an essential purchase for geoscience students at a variety of levels studying paleoclimatology, paleoceanography, oceanography, historical geology, global change, Quaternary science and Earth-system science.
Table of Contents
The Authors viii
Foreword from First Edition x
Acknowledgments xi
Book Introduction to the Second Edition for Students and Instructors xii
About the Companion Website xvii
1 Chapter 1. Introduction to Paleoclimate Records
3 Part 1.1. Archives and Proxies
13 Part 1.2. Obtaining Cores from Terrestrial and Marine Paleoclimate Archives
27 Part 1.3. Owens Lake - An Introductory Case Study of Paleoclimate Reconstruction
31 Chapter 2. Seafloor Sediments
33 Part 2.1. Sediment Predictions
34 Part 2.2. Core Observation and Description
41 Part 2.3. Sediment Composition
52 Part 2.4. Seafloor Sediment Synthesis
57 Chapter 3. Geologic Time and Geochronology
59 Part 3.1. The Geologic Timescale
62 Part 3.2. Principles of Stratigraphy and Determining Relative Ages
64 Part 3.3. Radiometric Age Dating Fundamentals
69 Part 3.4. Using 40K - 40Ar Dating to Determine the Numerical Ages of Layered Volcanic Rocks
76 Part 3.5. Using Uranium Series Dating to Determine Changes in Growth Rate of Speleothems
89 Chapter 4. Paleomagnetism and Magnetostratigraphy
91 Part 4.1. Earth’s Magnetic Field Today and the Paleomagnetic Record of Deep‐Sea Sediments
100 Part 4.2. History of Discovery: Paleomagnetism in Ocean Crust and Marine Sediments
108 Part 4.3. Using Paleomagnetism to Test the Seafloor Spreading Hypothesis
114 Part 4.4. The Geomagnetic Polarity Timescale
119 Chapter 5. Microfossils and Biostratigraphy
121 Part 5.1. What Are Microfossils? Why Are They Important in Climate Change Science?
130 Part 5.2. Microfossils in Deep‐Sea Sediments
137 Part 5.3. Application of Microfossil First and Last Occurrences
144 Part 5.4. Using Microfossil Datums to Calculate Sedimentation Rates
149 Part 5.5. How Reliable Are Microfossil Datums?
156 Part 5.6. Organic‐Walled Microfossils: Marine Dinoflagellates and Terrestrial Pollen and Spores
165 Chapter 6. CO2 as a Climate Regulator During the Phanerozoic and Today
167 Part 6.1. The Short‐Term Global Carbon Cycle
169 Part 6.2. CO2 and Temperature
179 Part 6.3. Recent Changes in CO2
183 Part 6.4. The Long‐Term Global Carbon Cycle, CO2, and Phanerozoic Climate History
191 Part 6.5. Carbon Isotopes as a Tool for Tracking Changes in the Carbon Cycle
200 Chapter 7. Oxygen Isotopes as Proxies of Climate Change
202 Part 7.1. Introduction to Oxygen Isotope Records from Ice and Ocean Sediments
205 Part 7.2. The Hydrologic Cycle and Isotopic Fractionation
209 Part 7.3. δ18O in Meteoric Water and Glacial Ice
218 Part 7.4. δ18O in Marine Sediments
226 Chapter 8. Climate Cycles
228 Part 8.1. Patterns and Periodicities
245 Part 8.2. Orbital Metronome
250 Part 8.3. Glacial-Interglacial Periods and Modern Climate Change
255 Chapter 9. The Paleocene-Eocene Thermal Maximum (PETM) Event
257 Part 9.1. An Important Discovery
260 Part 9.2. Global Consequences of the PETM
296 Part 9.3. Two Hypotheses for the Cause of the PETM
299 Part 9.4. Rates of Onset and Duration of Event
306 Part 9.5. Global Warming Today and Lessons from the PETM
314 Chapter 10. Glaciation of Antarctica: The Oi1 Event
316 Part 10.1. Initial Evidence
321 Part 10.2. Evidence for Global Change
342 Part 10.3. Mountain Building, Weathering, CO2 and Climate
349 Part 10.4. Legacy of the Oi1 Event: The Development of the Psychrosphere
355 Chapter 11. Antarctic Climate Variability in the Neogene
358 Part 11.1. What Do We Think We Know About the History of Antarctic Climate?
362 Part 11.2. What is Antarctica’s Geographic and Geologic Context?
375 Part 11.3. Selecting Drillsites to Best Answer our Questions
379 Part 11.4. What Sediment Facies are Common on the Antarctic Margin?
390 Part 11.5. The BIG Picture of ANDRILL 1‐B
398 Chapter 12. Pliocene Warmth as an Analog for Our Future
400 Part 12.1. The Last 5 Million Years
407 Part 12.2. Pliocene Latitudinal Temperature Gradient
414 Part 12.3. Estimates of Pliocene CO2
416 Part 12.4. Sea Level Past, Present, and Future
430 Chapter 13. Climate, Climate Change, and Life
432 Part 13.1. Initial Ideas
433 Part 13.2. The Long View: “Precambrian” and Phanerozoic Life and Climate
441 Part 13.3. Examples of Cenozoic Terrestrial Evolution and Climate Connections
458 Part 13.4. Examples of Cenozoic Marine Biotic Evolution and Climate Connections
469 Part 13.5. Humanity, Climate, and Life
481 Part 13.6. Humanity and Future Climate: At a Tipping Point
487 Chapter 14. Climate Change and Civilization
489 Part 14.1. Climate Change Here and Now
497 Part 14.2. Evidence of Climatic Stress on Ancient Maya Civilization
513 Part 14.3. The Precipitation Record of the North American Southwest: The Physical Record and Human Response
536 Index
