CONTENTS

PREFACE

Chapter 1. Introduction: Earth and Life as Natural Systems

Introduction

The Power and Limitations of Scientific Reductionism

Chaos

“Systems”

Characteristics of “Natural Systems”

Natural Systems Are Out of Equilibrium

Natural Systems Are Maintained by External Energy Sources

“Steady-State Disequilibrium” Is Maintained by Feedbacks and Cycles

Summary

Supplementary Readings

Chapter 2. The Setting: The Big Bang and Galaxy Formation

Introduction

The Big Bang

The Red Shift: Measuring Velocity

Measuring Distance

The Velocity-Distance Relationship: Dating the Beginning

Added Support for the Big Bang Hypothesis

An Expanding Universe and Dark Energy

Aftermath of the Big Bang

Summary

Supplementary Readings

Chapter 3. The Raw Material: Synthesis of Elements in Stars

Introduction

The Chemical Composition of the Sun

Hydrogen, Helium, Galaxies, Stars

Descriptive Atomic Physics

Element Production during the Big Bang

Element Formation in Stars

Element Synthesis by Neutron Capture

Evidence Supporting the Stellar Hypothesis

Summary

Supplementary Readings

Chapter 4. Preliminary Fabrication: Formation of Organic and Inorganic Molecules

Introduction

Molecules

States of Matter

Volatility

Density

The Two Great Classes of Molecules: Inorganic and Organic

Minerals

Organic Molecules

Environments of Molecular Construction

Summary

Chapter 5. The Heavy Construction: The Formation of Planets and Moons from a Solar Nebula

Introduction

Planetary Vital Statistics

Planetary Mass

Planetary Densities

Planetary Composition

Evidence from Meteorites

Scenario for Solar System Creation

Understanding the Chemical Compositions of the Terrestrial Planets

Summary

Supplementary Readings

Chapter 6. The Schedule: Quantifying the Timescale with Radionuclides

Introduction

Measuring Time with Radioactive Decay

The Isochron Technique of Radioactive Dating

Age of the Chondrites and Earth

Age of the Elements

Unlocking the Secrets of Ancient Short-lived Processes with Extinct Radionuclides

26Al and the Presence of Supernovas in the Vicinity of the Solar Nebula

Summary

Supplementary Reading

Chapter 7. Interior Modifications: Segregation into Core, Mantle, Crust, Ocean, and Atmosphere

Introduction

Earth Structure

Chemical Composition of Earth’s Layers

Chemical Affinities of the Elements

Origin of Earth’s Layers

Separation of Core from Mantle

Timing of Core Formation

Origin of the Crust

Origin of the Atmosphere and Ocean

Summary

Chapter 8. Contending with the Neighbors: Moons, Asteroids, Comets, and Impacts

Introduction

The Diversity of Objects in the Solar System

Origin of the Moon

Using Impacts to Date Planetary Surfaces

Lunar Interior Modifications

History of Impacts in the Solar System

Implications for the Earth

Future Impacts

Summary

Supplementary Readings

Chapter 9. Making It Comfortable: Running Water, Temperature Control, and Sun Protection

Introduction

The Planetary Volatile Budget

Evidence for Liquid Water before 4.0 Ga

Stable Isotope Fractionation

Controls on Volatiles at the Surface

Atmospheric Loss to Space

Cycling of Volatiles between the Surface and Earth’s Interior

Surface Temperature

Earth’s Long-Term Thermostat

A Lesson from Venus

Snowball Earth

Sun Protection

Summary

Supplementary Readings

Chapter 10. Establishing the Circulation: Plate Tectonics

Introduction

The Static Earth Viewpoint

Continental Drift Theory

New Data from the Ocean Floor

Evidence from Paleomagnetism

Global Distribution of Seismicity

The Theory of Plate Tectonics

The Plate Tectonic Revolution

Movements through Time

Summary

Supplementary Readings

Chapter 11. Internal Circulation: Mantle Convection and Its Relationship to the Surface

Introduction

Movement of Earth’s Interior

Earth’s Topography and Mantle Flow

Mantle Convection

Must the Mantle Convect?

Does Plate Geometry Correspond to Mantle Convection Cells?

Active Mantle Upwelling: Plume Heads and Tails

Formation of the Ocean Crust at Spreading Centers

Summary

Supplementary Readings

Chapter 12. Linking the Layers: Solid Earth, Liquid Ocean, and Gaseous Atmosphere

Introduction

The Global System of Ocean Ridges

Hydrothermal Circulation at Spreading Centers

Ocean Ridges and Habitability

The Puzzle of Seawater Composition

Element Transport to the Subduction Zone

Geochemical Processing at Convergent Margins

Cause of Melting and Volcanism at Convergent Margins

Element Transport to the Continental Crust

Final Consequences of Plate Recirculation

Summary

Supplementary Readings

Chapter 13. Colonizing the Surface: The Origin of Life as a Planetary Process

Introduction

Life and the Universe

The Unity of Life

Life Is Cellular

All Life Uses the Same Groups of Molecules

All Life Uses the Same Chemical Machinery

Earliest Life

When Did Life Begin?

Life’s Origin

Steps in the Path to Life

Elemental and Simple Molecular Building Blocks

Making the Essential Biochemical Ingredients

Building Complex Molecules

A Cellular Container

The Missing Links

Some General Considerations on the Origin of Life

Summary

Supplementary Readings

Chapter 14. Dealing with the Competition: The Roles of Evolution and Extinction in Creating the Diversity of Life

Introduction

History of Life and Earth Revealed through the Rock Record

Relating Fossils to Present-Day Life: The Theory of Evolution

The DNA Revolution

The Extinction Half of Evolution

Summary

Supplementary Readings

Chapter 15. Energizing the Surface: Coevolution of Life and Planet to Create a Planetary Fuel Cell

Introduction

Life as an Electrical Current

A Reduced Early Earth

The First Three Energy Revolutions

The Planetary Fuel Cell

Summary

Chapter 16. Exterior Modifications: The Record of Oxidation of the Planetary Surface

Introduction

Earth and Oxygen

Carbon: The Record of Oxygen Production

Carbon: Evidence from the Rock Record

Iron and Sulfur: The Record of Oxygen Consumption

Iron: Evidence from the Rock Record

Sulfur: Evidence from the Rock Record

Evidence for High O2 in the Phanerozoic

Oxygen from 2.0 Ga to 0.6 Ga

Global Oxygen Mass Balance

Summary

Supplementary Readings

Chapter 17. Planetary Evolution: The Importance of Catastrophes and the Question of Directionality

Introduction

Planetary Evolution during the Phanerozoic

Causes of Extinction Events

The Cretaceous/Tertiary Extinction

The Permo-Triassic Extinction

Plate Tectonics and Evolution

Principles of Planetary Evolution?

Increased Relationship and Complexity

Change in Energy Utilization with Time

Speculations on the Possibility of Directionality to Evolution

Evolution of Habitability

Summary

Supplementary Readings

Chapter 18. Coping with the Weather: Causes and Consequences of Naturally Induced Climate Change

Introduction

Intermediate Term Climate Variations: Ice Ages

Orbital Cycles

Abrupt Climate Change

The Great Ocean Conveyor

Human Impacts

Summary

Supplementary Readings

Chapter 19. The Rise of Homo Sapiens: Access to Earth’s Treasure Chest Permits a Planetary Takeover

Introduction

Dawn of the Human Era

The Human Energy Revolution

Earth’s Treasure Chest

Classes of Resources

Resources with Short Recycling Times: Air and Water

Vast Resources with Recycling Potential: Metals

Finite Resources with No Recycling

Fossil Fuels

Soils

Biodiversity

Summary

Chapter 20. Mankind at the Helm: Human Civilization in a Planetary Context

Introduction

Human Impacts on the Earth

Climate

Ocean Acidification

Biodiversity

Future Prospects

Historical Perspectives on the Future

Possible Solutions

Solving Greenhouse Gas Accumulation

Energy from the Sun, Wind, and Atom

Carbon Capture and Sequestration

The Broader Problem

An Anthropozoic Era?

Summary

Supplementary Readings

Chapter 21. Are We Alone? The Question of Habitability in the Universe

Introduction

Comparative Planetology—Lessons from Venus and Mars

Planet Finding

New Results from Kepler

The Number of Other Inhabited Planets in the Galaxy: A Probabilistic Approach

Human Civilization in the Context of Planetary Evolution and Life in the Universe

Summary

Supplementary Readings

GLOSSARY

INDEX