How to Build a Habitable Planet

Isochron Technique of Radioactive Dating 150 Age of the Chondrites and Earth 154 Age of the Elements 157 Unlocking the Secrets of Ancient Short-lived Processes with Extinct Radionuclides 164 26Al and the Presence of Supernovas in the Vicinity of the Solar Nebula 165 Summary 168 Supplementary Reading 169 Chapter 7. Interior Modifications: Segregation into Core, Mantle, Crust, Ocean, and Atmosphere 171 Introduction 172 Earth Structure 173 Chemical Composition of Earth's Layers 180 Chemical Affinities of the Elements 183 Origin of Earth's Layers 188 Separation of Core from Mantle 189 Timing of Core Formation 191 Origin of the Crust 194 Origin of the Atmosphere and Ocean 204 Summary 206 Chapter 8. Contending with the Neighbors: Moons, Asteroids, Comets, and Impacts 209 Introduction 210 The Diversity of Objects in the Solar System 212 Origin of the Moon 218 Using Impacts to Date Planetary Surfaces 223 Lunar Interior Modifications 230 History of Impacts in the Solar System 236 Implications for the Earth 239 Future Impacts 245 Summary 246 Supplementary Readings 247 Chapter 9. Making It Comfortable: Running Water, Temperature Control, and Sun Protection 249 Introduction 250 The Planetary Volatile Budget 251 Evidence for Liquid Water before 4.0 Ga 253 Stable Isotope Fractionation 255 Controls on Volatiles at the Surface 257 Atmospheric Loss to Space 258 Cycling of Volatiles between the Surface and Earth's Interior 264 Surface Temperature 265 Earth's Long-Term Thermostat 271 A Lesson from Venus 276 Snowball Earth 278 Sun Protection 280 Summary 282 Supplementary Readings 282 Chapter 10. Establishing the Circulation: Plate Tectonics 285 Introduction 286 The Static Earth Viewpoint 287 Continental Drift Theory 289 New Data from the Ocean Floor 291 Evidence from Paleomagnetism 293 Global Distribution of Seismicity 298 The Theory of Plate Tectonics 301 The Plate Tectonic Revolution 306 Movements through Time 309 Summary 311 Supplementary Readings 312 Chapter 11. Internal Circulation: Mantle Convection and Its Relationship to the Surface 315 Introduction 316 Movement of Earth's Interior 317 Earth's Topography and Mantle Flow 319 Mantle Convection 322 Must the Mantle Convect? 325 Does Plate Geometry Correspond to Mantle Convection Cells? 328 Active Mantle Upwelling: Plume Heads and Tails 335 Formation of the Ocean Crust at Spreading Centers 342 Summary 347 Supplementary Readings 347 Chapter 12. Linking the Layers: Solid Earth, Liquid Ocean, and Gaseous Atmosphere 349 Introduction 350 The Global System of Ocean Ridges 351 Hydrothermal Circulation at Spreading Centers 354 Ocean Ridges and Habitability 362 The Puzzle of Seawater Composition 362 Element Transport to the Subduction Zone 366 Geochemical Processing at Convergent Margins 369 Cause of Melting and Volcanism at Convergent Margins 369 Element Transport to the Continental Crust 375 Final Consequences of Plate Recirculation 377 Summary 379 Supplementary Readings 381 Chapter 13. Colonizing the Surface: The Origin of Life as a Planetary Process 383 Introduction 384 Life and the Universe 385 The Unity of Life 390 Life Is Cellular 390 All Life Uses the Same Groups of Molecules 391 All Life Uses the Same Chemical Machinery 396 Earliest Life 398 When Did Life Begin? 401 Life's Origin 406 Steps in the Path to Life 408 Elemental and Simple Molecular Building Blocks 409 Making the Essential Biochemical Ingredients 410 Building Complex Molecules 412 A Cellular Container 415 The Missing Links 417 Some General Considerations on the Origin of Life 420 Summary 424 Supplementary Readings 424 Chapter 14. Dealing with the Competition: The Roles of Evolution and Extinction in Creating the Diversity of Life 427 Introduction 428 History of Life and Earth Revealed through the Rock Record 432 Relating Fossils to Present-Day Life: The Theory of Evolution 438 The DNA Revolution 441 The Extinction Half of Evolution 447 Summary 450 Supplementary Readings 451 Chapter 15. Energizing the Surface: Coevolution of Life and Planet to Create a Planetary Fuel Cell 453 Introduction 454 Life as an Electrical Current 455 A Reduced Early Earth 457 The First Three Energy Revolutions 463 The Planetary Fuel Cell 469 Summary 472 Chapter 16. Exterior Modifications: The Record of Oxidation of the Planetary Surface 475 Introduction 476 Earth and Oxygen 477 Carbon: The Record of Oxygen Production 480 Carbon: Evidence from the Rock Record 483 Iron and Sulfur: The Record of Oxygen Consumption 486 Iron: Evidence from the Rock Record 488 Sulfur: Evidence from the Rock Record 493 Evidence for High O2 in the Phanerozoic 497 Oxygen from 2.0 Ga to 0.6 Ga 498 Global Oxygen Mass Balance 502 Summary 506 Supplementary Readings 507 Chapter 17. Planetary Evolution: The Importance of Catastrophes and the Question of Directionality 509 Introduction 510 Planetary Evolution during the Phanerozoic 511 Causes of Extinction Events 516 The Cretaceous/Tertiary Extinction 517 The Permo-Triassic Extinction 521 Plate Tectonics and Evolution 526 Principles of Planetary Evolution? 527 Increased Relationship and Complexity 527 Change in Energy Utilization with Time 529 Speculations on the Possibility of Directionality to Evolution 531 Evolution of Habitability 534 Summary 536 Supplementary Readings 537 Chapter 18. Coping with the Weather: Causes and Consequences of Naturally Induced Climate Change 539 Introduction 540 Intermediate Term Climate Variations: Ice Ages 541 Orbital Cycles 544 Abrupt Climate Change 555 The Great Ocean Conveyor 560 Human Impacts 564 Summary 565 Supplementary Readings 565 Chapter 19. The Rise of Homo Sapiens: Access to Earth's Treasure Chest Permits a Planetary Takeover 567 Introduction 568 Dawn of the Human Era 569 The Human Energy Revolution 573 Earth's Treasure Chest 575 Classes of Resources 580 Resources with Short Recycling Times: Air and Water 580 Vast Resources with Recycling Potential: Metals 586 Finite Resources with No Recycling 589 Fossil Fuels 589 Soils 593 Biodiversity 593 Summary 594 Chapter 20. Mankind at the Helm: Human Civilization in a Planetary Context 597 Introduction 599 Human Impacts on the Earth 600 Climate 600 Ocean Acidification 611 Biodiversity 614 Future Prospects 620 Historical Perspectives on the Future 628 Possible Solutions 632 Solving Greenhouse Gas Accumulation 635 Energy from the Sun, Wind, and Atom 635 Carbon Capture and Sequestration 637 The Broader Problem 643 An Anthropozoic Era? 644 Summary 646 Supplementary Readings 646 Chapter 21. Are We Alone? The Question of Habitability in the Universe 649 Introduction 650 Comparative Planetology--Lessons from Venus and Mars 652 Planet Finding 654 New Results from Kepler 659 The Number of Other Inhabited Planets in the Galaxy: A Probabilistic Approach 661 Human Civilization in the Context of Planetary Evolution and Life in the Universe 665 Summary 667 Supplementary Readings 668 Glossary 669 Index 687