Human Impacts on Weather and Climate

William R. Cotton, Roger A. Pielke9780521600569, 0521600561

This new edition of Human Impacts on Weather and Climate examines the scientific and political debates surrounding anthropogenic impacts on the Earths climate and presents the most recent theories, data and modeling studies. The book discusses the concepts behind deliberate human attempts to modify the weather through cloud seeding, as well as inadvertent modification of weather and climate on the regional scale. The natural variability of weather and climate greatly complicates our ability to determine a clear cause-and-effect relationship to human activity. The authors describe the basic theories and critique them in simple and accessible terms. This fully revised edition will be a valuable resource for undergraduate and graduate courses in atmospheric and environmental science, and will also appeal to policy makers and general readers interested in how humans are affecting the global climate.

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Table of contents :
Cover……Page 1
Half-title……Page 3
Title……Page 5
Copyright……Page 6
Contents……Page 7
Acknowledgments……Page 11
Part I The rise and fall of the science of weather modification by cloud seeding……Page 13
1 The rise of the science of weather modification by cloud seeding……Page 15
1.1 Project Cirrus……Page 17
2.2 The static mode of cloud seeding……Page 21
2.3.2 Fundamental concepts……Page 32
2.4.1 Introduction……Page 44
2.4.2 Basic physical concepts of precipitation formation in warm clouds……Page 45
2.4.3 Strategies for enhancing rainfall from warm clouds……Page 48
2.5.1 Introduction……Page 52
2.5.2 Basic concepts of hailstorms and hail formation……Page 53
The Soviet hail model……Page 63
Conceptual model of hail formation in ordinary multicell thunderstorms……Page 64
Conceptual model of hailstone growth in supercell thunderstorms……Page 65
The Soviet hail suppression scheme……Page 68
The glaciation concept……Page 69
The embryo competition concept……Page 70
Early rainout and/or trajectory lowering liquid water depletion by salt seeding……Page 71
2.5.4 Field confirmation of hail suppression techniques……Page 73
2.6.1 Basic conceptual model of hurricanes……Page 75
2.6.3 STORMFURY field experiments……Page 77
3 The fall of the science of weather modification by cloud seeding……Page 79
Part II Inadvertent human impacts on regional weather and climate……Page 85
4.1 Cloud condensation nuclei and precipitation……Page 87
4.2 Aircraft contrails……Page 94
4.3 Ice nuclei and precipitation……Page 97
4.4 Other pollution effects……Page 98
4.5.1 Direct radiative forcing……Page 99
4.5.2 Indirect effects of dust……Page 100
5.1 Introduction……Page 102
5.2 Urban increases in CCN and IN concentrations and spectra……Page 103
5.3 The glaciation mechanism……Page 104
5.4 Impact of urban land use on precipitation and weather……Page 105
5.4.2 Clouds and precipitation deduced from radar studies……Page 109
Additional reading……Page 113
Concepts……Page 114
Surface air moist enthalpy……Page 118
6.1.2 Boundary-layer effects……Page 120
6.1.3 Local wind circulations……Page 123
6.1.5 Mesoscale and regional horizontal perspective……Page 124
6.2.1 Colorado……Page 130
6.2.2 Nebraska……Page 133
6.4.1 Historical overview……Page 143
6.4.3 Western Australia……Page 144
6.4.4 Middle East……Page 145
6.5.2 Amazon……Page 147
6.5.3 Africa……Page 149
6.6 Regional vegetation feedbacks……Page 150
6.7 Conclusion……Page 156
Additional reading……Page 159
7 Concluding remarks regarding deliberate and inadvertent human impacts on regional weather and climate……Page 160
Part III Human impacts on global climate……Page 163
8.1 Overview……Page 165
8.2 Atmospheric radiation……Page 167
8.2.1 Absorption and scattering by gases……Page 168
8.2.2 Absorption and scattering by aerosols……Page 170
8.2.3 Absorption and scattering by clouds……Page 171
8.2.4 Global energy balance and the greenhouse effect……Page 172
8.2.5 Changes in solar luminosity and orbital parameters……Page 173
8.2.7 Surface properties……Page 177
8.2.8 Assessment of the relative radiative effect of carbon dioxide and water vapor……Page 178
8.3.1 Water vapor feedbacks……Page 186
8.3.2 Cloud feedbacks……Page 188
8.3.3 Surface albedo feedbacks……Page 191
8.3.4 Ocean feedbacks……Page 192
8.4 Views of the Intergovernmental Panel on Climate Change and the National Research Council of climate forcings……Page 193
Additional reading……Page 197
9.1 Introduction……Page 199
9.2 Direct aerosol effects……Page 200
9.3 Aerosol impacts on clouds: the Twomey effect……Page 204
9.4 Aerosols in mixed-phase clouds and climate……Page 210
9.5 Aerosols, deep convection, and climate……Page 213
10.1 Introduction……Page 215
10.2.1 The war scenarios……Page 217
10.2.2 Smoke production……Page 218
10.2.3 Vertical distribution of smoke……Page 219
10.2.4 Scavenging and sedimentation of smoke……Page 220
10.2.5 Water injection and mesoscale responses……Page 222
10.2.6 Other mesoscale responses……Page 224
The acute phase……Page 225
10.2.8 Biological effects……Page 228
10.3 Summary of the status of the nuclear winter hypothesis……Page 230
11.1 Land-use/land-cover changes……Page 232
11.2 Historical land-use change……Page 233
11.3 Global perspective……Page 236
11.4 Quantifying land-use/land-cover forcing of climate……Page 244
11.5 Atmosphere–vegetation interactions……Page 249
11.6 The abrupt desertification of the Sahara……Page 252
Additional reading……Page 254
E.1 The importance and underappreciation of natural variability……Page 255
E.2 The dangers of overselling……Page 256
E.3 The capricious administration of science and technology……Page 259
E.4 Scientific credibility and advocacy……Page 260
E.5 Should society wait for hard scientific evidence?……Page 262
E.6 Politics and science……Page 263
E.7 Conclusions……Page 264
Additional readings……Page 265
References……Page 267
Index……Page 317