Carbon in the Geobiosphere (eBook)

Preface 8
Acknowledgements 14
Picture Credits on the Front Cover 18
Contents 20
1 Brief Overview of Carbon on Earth 23
1 An Unusual Look at EarthÌs Shells 24
2 Global Carbon Cycle 29
3 Fundamental Equation of a Cycle and Carbon Flows 36
4 Carbon in Fossil Fuels 40
5 Feedbacks in the Carbon Cycle 43
2 Earths Volatile Beginnings 45
1 The Major Volatiles 45
2 Primordial Atmosphere-Ocean System 57
3 Carbon Dioxide 62
4 Summary and Speculations 67
5 An Early Biosphere 71
3 Heat Balance of the Atmosphere and Carbon Dioxide 83
1 Heat Sources at the Earth’s Surface 84
2 Solar Heating and Radiation Balance 85
3 Greenhouse Effect 91
4 Temperature of a Prebiotic Atmosphere 102
5 CO2 and Climate Change 105
4 Mineralogy, Chemistry, and Reaction Kinetics of the Major Carbonate Phases 111
1 Carbonate Minerals 112
2 Calcites 115
3 Dolomite 123
4 Aragonite 127
5 Carbonate Dissolution and Precipitation Kinetics 132
6 Carbonate Precipitation and Dissolution in Marine Ecosystems 137
7 Some Geological Considerations 138
5 Carbon Dioxide in Natural Waters 145
1 Dissolution and Dissociation of CO2 in Water 146
2 CO2 Transfer from Atmosphere to Water 155
3 Calcite and Aragonite in Natural Waters 159
4 Degree of Saturation with Respect to Carbonate Minerals 160
5 CO2 Phases: Gas, Liquid, Hydrate, Ice 164
6 Air-Sea CO2 Exchange Due to Carbonate and Organic Carbon Formation 170
6 Isotopic Fractionation of Carbon: Inorganic and Biological Processes 187
1 Isotopic Species and Their Abundance 187
2 Isotopic Concentration Units and Mixing 189
3 Fractionation in Inorganic Systems 192
4 Photosynthesis and Plant Physiological Responses to CO2 196
5 Isotopic Fractionation and 13C Cycle 206
6 Long-Term Trends 211
7 Sedimentary Rock Record and Oceanic and Atmospheric Carbon 215
1 Geologic Time Scale and the Sedimentary Record 216
2 The Beginnings of Sedimentary Cycling 217
3 Broad Patterns of Sediment Lithologies 219
4 Differential Cycling of the Sedimentary Mass and Carbonates 221
5 Sedimentary Carbonate System 224
6 Evaporites and Fluid Inclusions 230
7 Isotopic Trends 233
8 Summary of the Phanerozoic Rock Record in Terms of Ocean Composition 242
8 Weathering and Consumption of CO2 247
1 Weathering Source: Sedimentary and Crystalline Lithosphere 248
2 Dissolution at the Earth’s Surface 254
3 Mineral-CO2 Reactions in Weathering 259
4 CO2 Consumption from Mineral-Precipitation Model 264
5 CO2 Consumption from Mineral-Dissolution Model 269
6 Environmental Acid Forcing 274
9 Carbon in the Oceanic Coastal Margin 277
1 The Global Coastal Zone 278
2 Carbon Cycle in the Coastal Ocean 284
3 Inorganic and Organic Carbon 291
4 Marine Calcifying Organisms and Ecosystems 300
5 Present and Future of the Coastal Ocean Carbon System 306
10 Natural Global Carbon Cycle through Time 311
1 The Hadean to Archean 311
2 The Archean to Proterozoic 315
3 The Phanerozoic 319
4 Pleistocene to Holocene Environmental Change 325
11 The Carbon Cycle in the Anthropocene 341
1 Characteristics of the Anthropocene 341
2 Major Perturbations of the Carbon Cycle: 1850 to the Early 21st Century 343
3 Partitioning of the Carbon, Nitrogen, and Phosphorus Fluxes 348
4 The Fundamental Carbon Problem of the Future 358
Bibliographic References 365
Index 405

Chapter 1 Brief Overview of Carbon on Earth (p. 1)

In the minds of the broad public, carbon dioxide is associated primarily, if not exclusively, with considerations of global warming. This topic has been the focus of undoubtedly great attention in the last decades of the 20th and in the early 21st century owing to the coverage of the subject of global warming and climate change by the news media drawing their information from the results of scientific studies.

The role of carbon dioxide as one of the gases that warm the Earth’s atmosphere by absorption of infrared or longwave, outgoing Earth radiation has been known since the work of the French scientist Jean-Baptiste-Joseph Fourier in the early nineteenth century and that of the Irish polymath John Tyndall in the middle part of that century.

The similar role of water vapor as a greenhouse gas was also recognized by John Tyndall in 1863. In his studies of the riddle of the causes of the ice ages, the Swedish chemist Svante Arrhenius in the mid-1890s did a series of mathematical calculations and showed that if the amount of atmospheric CO2 were cut in half, the world would be 4 to 5C cooler.

He also concluded that a doubling of the CO2 concentration would lead to a 5 to 6C increase in global mean temperature. Furthermore, he recognized the fact that the burning of coal and oil emits CO2 to the atmosphere and could lead to warming of the planet because of human activities (Chapter 3).

However, it was only an increase in the concentration of atmospheric carbon dioxide, measured systematically by Charles D. Keeling of the Scripps Institution of Oceanography in California since the mid-1950s in the air over the mountain Mauna Loa on the Island of Hawaii, that drew widespread attention to this gas as a product of fossil-fuel burning and land-use changes by the increasingly industrializing world.

In this first chapter of the book we describe the structure of the Outer Shell of the Earth on a global scale, the chemical composition of some of its parts on an atomic scale, the essentials of the carbon cycle in modern time, the connections between the inorganic and biological processes within the carbon cycle, and the estimated occurrences of the main types of fossil fuels that are believed to be the major source of the increase in atmospheric carbon dioxide in the industrial age of the last 150 years.

This material provides an overview of the global carbon cycle and the framework for discussion of various aspects of the cycle in the chapters that follow. In the concerns about global warming and the shorter-term increase of atmospheric carbon dioxide, three facts are nearly forgotten: one is the long-term cooling of the Earth’s surface in the last 30 million years, since ice cover began to develop in Antarctica, another is the periodic glaciations during the last 1 million years that were accompanied by rises and declines in atmospheric carbon dioxide concentration, and the third is the primary importance of carbon dioxide to plant growth.

The long history of carbon on Earth begins with the Earth’s accretion 4.55 billion years ago (Fig. 1.1) and it underlies not only the beginning and evolution of organic life on Earth, but also a great variety of the processes that have shaped the geological environment since the early days of the planet.