What can we expect as global change progresses? Will there be thresholds that trigger sudden shifts in environmental conditions--or that cause catastrophic destruction of life?

Effects of Past Global Change on Life explores what earth scientists are learning about the impact of large-scale environmental changes on ancient life--and how these findings may help us resolve today's environmental controversies.

Leading authorities discuss historical climate trends and what can be learned from the mass extinctions and other critical periods about the rise and fall of plant and animal species in response to global change. The volume develops a picture of how environmental change has closed some evolutionary doors while opening others--including profound effects on the early members of the human family.

An expert panel offers specific recommendations on expanding research and improving investigative tools--and targets historical periods and geological and biological patterns with the most promise of shedding light on future developments.

This readable and informative book will be of special interest to professionals in the earth sciences and the environmental community as well as concerned policymakers.

Contents

• Panel on Effects of Past Global Change on Life
• Board on Earth Sciences and Resources
• Commission on Geosciences, Environment, and Resources
• Studies in Geophysics
• Preface
• Overview and Recommendations
• 1. Oxygen and Proterozoic Evolution: An Update
  • Abstract
  • Introduction
  • The Early Proterozoic Eon
  • The End of the Proterozoic Eon
  • Conclusions
  • Acknowledgments
  • References
• 2. Impact of Late Ordovician Glaciation-Deglaciation on Marine Life
  • Abstract
  • Introduction
  • Data Summaries
  • The Time Frame
  • The Paleogeographic Framework
  • Geochemical Evidence of Deep Ocean Ventilation
  • Patterns in Extinction and Reradiation
  • Environmental-Organismal Changes: A Summary
  • References
• 3. Global Change Leading to Biodiversity Crisis in a Greenhouse World: The Cenomanian-Turonian (Cretaceous) Mass Extinction
  • Abstract
  • Introduction
  • High-Resolution Approach to Documenting Ancient Environmental Change
  • The Cenomanian-Turonian (C-T) Mass Extinction—an Ancient Global Biodiversity Crisis in a Chaotic Greenhouse World
  • A Case History: the Pueblo, Colorado, C-T Boundary Section
  • Establishing a Chronology for Environmental Decline and Mass Extinction across the C-T Boundary
  • A Timetable for Cenomanian-Turonian Mass Extinction
  • Interpretations And Conclusions
  • References
  • Appendix
• 4. Cretaceous-Tertiary (K/T) Mass Extinction: Effect of Global Change on Calcareous Microplankton
  • Abstract
  • Introduction
  • How Complete Are K/T Boundary Sections?
  • Species Response To K/T Disturbance
  • Population Response to K/T Disturbance
  • Magnitude of K/T Disturbance
  • Are Specific Habitats Selectively Destroyed?
  • Discussion And Summary
  • Acknowledgments
  • References
• 5. Terminal Paleocene Mass Extinction in the Deep Sea: Association with Global Warming
  • Abstract
  • Introduction
  • Terminal Paleocene Mass Extinction in the Deep Sea
  • Association Between Mass Extinction and Oceanic Warming
  • Cause of Mass Extinction In Deep Sea
  • Cause of Oceanographic and Climate Change
  • Why the Early Paleogene?
  • Implications and Summary
  • Acknowledgments
  • References
• 6. Tropical Climate Stability and Implications for the Distribution of Life
  • Abstract
  • Introduction
  • Oxygen Isotopic Records of Low Latitude Temperatures
  • Arguments for Tropical Temperature Stability
  • Model-Derived Tropical Temperatures
  • Evidence for Tropical Salinity Differences
  • Summary of Tropical Climate Extremes
  • Climate Tolerances of Tropical Organisms
  • A Mid-Cretaceous Case Study
  • Discussion and Conclusions
  • References
• 7. Neogene Ice Age in the North Atlantic Region: Climatic Changes, Biotic Effects, and Forcing Factors
  • Abstract
  • Introduction
  • Climatic Events
  • Biotic Consequences
  • Forcing of Late Cenozoic Climatic Changes
  • Summary and Conclusions
  • References
• 8. The Response of Hierarchially Structured Ecosystems to Long-Term Climatic Change: A Case Study using Tropical Peat Swamps of Pennsylvanian Age
  • Abstract
  • Introduction
  • Late Carboniferous Wetlands
  • Coal Swamps as Hierarchically Organized Systems
  • Patterns of Change in Coal-Swamp Communities during the Pennsylvanian Period
  • Climate Change and Causation
  • Summary and Implications
  • References
• 9. The Late Cretaceous and Cenozoic History of Vegetation and Climate at Northern and Southern High Latitudes: A Comparison
  • Abstract
  • Introduction
  • Paleogeographic Framework
  • Summary Of High-Latitude Vegetational Changes
  • Comparison of Northern and Southern High-Latitude Vegetation
  • Acknowledgments
  • References
• 10. The Impact of Climatic Changes on the Development of the Australian Flora
  • Abstract
  • Uniqueness of the Australian System
  • Geological and Plate Tectonic Setting
  • Modern Vegetation of Australia
  • Factors Affecting Vegetation and Taxon-Based Changes
  • Major Tertiary Climatic Changes
  • Plant Megafossil Evidence for Climatic Change
  • Discussion
  • Acknowledgments
  • References
• 11. Global Climatic Influence on Cenozoic Land Mammal Faunas
  • Abstract
  • Introduction
  • Land Mammal Faunas and Their Response to Climatic Change
  • Mammalian Faunal Succession in North America
  • Results
  • Discussion
  • Conclusions
  • Acknowledgments
  • References
• 12. Biotic Responses to Temperature and Salinity Changes During Last Deglaciation, Gulf of Mexico
  • Abstract
  • Introduction
  • Results and Discussion
  • Conclusions
  • Acknowledgments
  • References
• 13. Pollen Records of Late Quaternary Vegetation Change: Plant Community Rearrangements and Evolutionary Implications
  • Introduction
  • Sensitivity of Pollen Data to Vegetation Patterns
  • Maps of Changing Taxon Distribution through Time
  • Implications For Species And Evolution
  • Time and Space Scales of Vegetational and Taxonomic Units
  • Space-Time Perspective
  • References
• 14. Climatic Forcing and the Origin of the Human Genus
  • Abstract
  • Introduction
  • Development In Apes, Humans, And Australopithecines
  • The Life of Gracile Australopithecines
  • The Nature Of Early Homo
  • Climatic Forcing
  • References

Support for this activity was provided by the Department of Energy, the National Science Foundation, the U.S. Geological Survey, and the National Oceanic and Atmospheric Administration.

NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competencies and with regard for appropriate balance.

This report has been reviewed by a group other than the authors according to procedures approved by a Report Review Committee consisting of members of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine.

The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce Alberts is president of the National Academy of Sciences.

The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. Robert M. White is president of the National Academy of Engineering.

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The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy's purposes of furthering knowledge and of advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce Alberts and Dr. Robert M. White are chairman and vice chairman, respectively, of the National Research Council.