Chemistry of the Climate System

726 Pages·2010·4.743 MB·english

by  Detlev Möller

Detlev Möller
Chemistry of the
Climate System
DE GRUYTER
Univ.-Prof.Dr.rer.nat.habil.DetlevMöller
BrandenburgischeTechnischeUniversitätCottbus
FakultätfürUmweltwissenschaftenundVerfahrenstechnik
LehrstuhlfürLuftchemieundLuftreinhaltung
Konrad-Wachsmann-Allee1
03046Cottbus
[email protected]
Thisbookhas168figuresand148tables.
ISBN978-3-11-019791-4
e-ISBN978-3-11-022835-9
LibraryofCongressCataloging-in-PublicationData
Möller,Detlev.
Chemistryoftheclimatesystem/byDetlevMöller.
p.cm.
ISBN978-3-11-019791-4
1.Atmosphericchemistry. 2.Meteorology. I.Title.
QC879.6.M648 2010
551.5161−dc22
2010028400
©2010WalterdeGruyterGmbH&Co.KG,Berlin/NewYork
Typesetting:MetaSystemsGmbH,Wustermark
Printingandbinding:Druckhaus„ThomasMüntzer“,BadLangensalza
PrintedinGermany
www.degruyter.com
Preface
Halfacenturyago,ChristianJunge,thefounding‘father’ofatmosphericchemistry
summarized the existing knowledge in his field of research. In 1960 Junge counted
only 75 research articles dealing with atmospheric chemistry and radioactivity.
Nowadaysthepublicationrateandnumberofresearchersinatmosphericchemistry
areordersofmagnitude greater.Manymajoradvanceshavebeen madesincethen.
For example in the early 1970s, the role of OH radicals in oxidizing gases, leading
to their removal from the atmosphere, was discovered. The necessary ingredients
to produce OH are ozone, water vapor, UV-B solar radiation. The catalytic role of
NO in producing ozone was also recognized at the beginning of the 1970’s. Until
then it was generally believed that tropospheric ozone was produced in the strato-
sphere and transported downwards into the troposphere. The feedstocks for the
creationofozoneareCO,CH andmanybiogenicgases.Bothnaturalandanthro-
4
pogenic processes are responsible for their emissions. Although the main photo-
chemical chain reactions are reasonably well known, their quantification needs
much further research. They all are parts of the biogeochemical cycles of carbon,
nitrogenandsulfur.Theycanalsoplayaroleinclimate,asdoesparticulatematter,
which, contrary to the greenhouse gases (CO , CH ), tends to cool the earth and
2 4
atmosphere.
In his book, Detlev Möller gives a thorough overview of the main chemical
processes that occur in the atmosphere, only a few of which have been mentioned
above. The novel title of this book “chemistry of the climate system” should direct
the attention of the reader to the fact that understanding atmospheric chemistry
is incomplete without considering interfacing neighboring reservoirs such as the
hydrosphere, the lithosphere and the biosphere.
An overviewof thetopics treated,is providedin theIntroduction. Itemphasizes
thatdrawingstrongborderlinesbetweendisciplinesmakesnosenseandthisisalso
valid for the various systems because they overlap and the most important proc-
esses can happen at their interfaces. Therefore, chemistry of the climate system
combines atmospheric with water, soil and biological chemistry. Another general
approachofthisbookliesintheincorporationofhistoricalfacts:despitetheorders
of magnitude more publications each year nowadays than in past, we should not
forgetthatcarefulobservationsweremadeandseriousconclusionsdrawnbymany
of our scientific ancestors.
ThetexthasitsrootsinabookwritteninGerman,entitled“Luft”andpublished
by DeGruyter in 2003. Although the text has been entirely rewritten and many
chapters have been replaced, the main emphasis on regarding the atmosphere as a
multiphasesystemisessentiallyunchanged.Moreover,byaddinginterfacialchemis-
try, the system is enlarged to a multireservoir system, encompassing the climate
system. At the end, however, is the central focus is chemistry. The author avoids
usingthetermenvironmentalchemistry,emphasizingthatsubstanceshavingspecific
physical and chemical properties can modify (chemical) systems in various direc-
tionsdependingonthemixtureandinitialconditions.Specialistsinphysics,chemis-
tryandbiologyaswellitsmanysubdisciplinesneedtounderstandwhattheirdisci-
plines can bring to the subject of climate system chemistry. This book is about
fundamental aspects of (chemical) climate change. But this book does not attempt
to review all of the research on this topic. At many sites in this book, “Further
Reading” is provided referring the reader to more specialized textbooks.
Thebookcomprisesthreelargefundamentalchapters:Chemicalevolution,phys-
ico-chemical fundamentals and substances and chemical reactions. Following the
Introduction, the chapter “Chemical Evolution” gives a brief history from the Big
Bang to the Anthropocene, the human influenced earth system. Detlev Möller de-
scribes the historical dimension in connecting the past with future developments.
Changingchemicalaircompositionisbasedonthreepillars:landusechange,burn-
ingoffossilfuelsandagriculturalfertilizing,allcausedbytherisingglobalpopula-
tion. The resulting air chemical “episodes” (acid rain, ozone, particulate matter)
are fairly well understood and end-of-pipe technologies to control air pollution
have been introduced. The remaining future challenge, limiting global warming
through reduced emission of CO , however can be achieved only by moving the
2
anthroposphere into a solar era, as suggested in chapter 2.8.4. Hence, Möller de-
finesglobalsustainablechemistryasacouplingbiogeochemicalcycleswithanthro-
pogenic matter cycles, almost importantly CO cycling.
2
Chapter4 briefly overviews the physical and chemical principles of transporting
andtransformingsubstancesinnaturalreservoirs,againwithanemphasisonmulti-
phase and interfacial processes. The texts on chemical reactions, multiphase proc-
esses, atmospheric removal and characteristic timescales are well written and easy
to read even for non-chemists. The third main chapter treats “Substances and
Chemical Reactions in the Climate System” according to the elements and their
compounds depending on the conditions of reactions and whether the substance
existsinthegaseousorcondensedphase.Thestructureisadaptedfrom“classical”,
substance oriented textbooks in chemistry: hydrogen, oxygen, nitrogen, sulfur,
phosphorous, carbon and halogens. Many excellent figures summarize chemical
pathways under different natural conditions and make it easy to understand com-
plex chemical processes.
Different appendixes provide useful information on abbreviations, quantities,
units and the earth geological time-scale. The respect brought to the history of
scienceisfulfilledbyanicebiographyincludingsomenotsowell-knownscientists.
Alltogether,thiswellwrittenandusefulbookfillsagapintheattempttoprovide
books written from the perspective of a particular discipline (chemistry) on an
interdisciplinary subject (the climate system) for readers and scientists from differ-
ent disciplines to learn (or teach) some chemistry outside of the laboratory retort
or industrial vessel.
Paul Crutzen
Nobel prize in Chemistry 1995
Prologue
10 years ago the publishing house de Gruyter asked me to write a book titled
“Luft” (Air), which was published in 2003. Paul Crutzen said that it was written
in the wrong language. It was written in German, my mother tongue. I percieved
it as a compliment that they wanted me to reach more international readers. My
first thank goes to de Gruyter, who offered me the opportunity to write another
book on air in English about 3 years ago. The German book “Air” belongs to a
planned series on water, air and soil (last one is not written yet) which means that
there were certain restrictions and wishes by the editor. But for this new book I
had absolute freedom to choose my own content; therefore I would like to express
a further thank to de Gruyter. The only wish from the editor was that this book
should contribute to the discussion on climate change.
This new book is not a (revised) translation of “Air” − I have only used a few
fundamental issues such as physico-chemistry and basic air chemistry, which now
is permanent knowledge of any textbook. I am a chemist; my original background
isphysical chemistrybutsince35 yearsIdealwith airchemistry(and airpollution
studies). Chemistry is the science of matter and matter distributes and cycles
through nature.
Theclimatesystemisapartandtheatmosphereanotherpartofthis.Theearth’s
climate system provides a habitable zone. I agree with scientists who argue that
human beings as a part of nature have altered the “natural system” to such an
extentthatwearenowunabletoreversethepresentsystembacktoapreindustrial
or even prehuman state. But the key question nowadays is how to maintain the
function of our climate system so that sustainable survival of humans is possible.
We can state that humans have become a global force in the chemical evolution
with respects to climate change by interrupting naturally evolved biogeochemical
cycles.Buthumansalsohaveallthefacilitiestoturnthe“chemicalrevolution”into
a sustainable chemical evolution.
Understandingonhowtheclimatesystemworksisprovidedbythenaturalscien-
ces (physics, chemistry and biology). This book focuses on the chemistry of the
climate system. But differentiating precisely between physics and chemistry makes
absolutely no sense when trying to understand the climate system. However, with-
out understanding biological laws − and we can probably include social laws here
as well considering that the biosphere has long ago been transformed into the
noosphere − we will neither understand climate change nor find solutions for cli-
mate control. Maybe this book will provoke people by bridging a state-of-the-art
textbook knowledge with ideas or opinions beyond “pure” chemistry. Without a
paradigmchangewithinthenext2−3decades(forexamplecarbondioxidecycling)
we will have little chance of climate control.
My knowledge is limited; therefore specialists will find gaps and missing things
in my book. A few weeks ago I visited a lecture by Professor Norimichi Takenaka
(Japan), who studied the decomposition of ammonium nitrite in drying dew drop-
lets with the formation of N − a disproportioning and fascinating pathway for
2
atmospheric NH and NO . Unfortunately, I did not know about this reaction,
3 x
eventhoughiswasalreadyknowninthe19thcentury,anditisanexactkeyexample
for interfacial chemistry, which is one focus of my book and my special interest in
thelastfewyearsafterstudyingmultiphasechemistryformanyyears.Ibelievethat
interfaces (or heterogeneous systems in other terms) in certain natural places pro-
vide special conditions for chemical reactions and therefore result in a turnover of
matter. Our knowledge about what happens in atmospheric multiphase chemistry,
despitemuchprogresswithinthelasttwodecades,isstilllimited(Ihopethatsome
issummarizedinthisbook).Butinterfacialchemistrymaybemoreimportant(and
almost more interesting) for controlling the climate system at the interface along
the atmosphere and earth surface, including natural waters, soils, plants, microor-
ganism and others.
Special thanks go to Professor Volker A. Mohnen, to whom I owe important
scientificstimulationoverthelast20years,includingtheimpulsetowritethisbook.
Finally I would like to thank my coworkers who accepted that I was not in the
institute a lot throughout the last two years (and who kept the business going); I
wrote this book in my office at my home in Berlin (day and night, weekday and
weekend: my special thank goes to my wife Ursula and my family), surrounded by
hundreds of books on chemistry (but also on history, physics and biology) of the
climatesystemfromthelast200years(andafewolderones).Thisbookisthefirst
book to be titled “Chemistry of the Climate System” to my knowledge and I hope
− no, I am sure that it is not going to be the last one. It stands between “special”
and“generic”;itispartlylikeatextbookandamonograph(anditmayevenappear
to be an ecopamphlet). Hence, this book is recommended to anybody who likes
nature and chemistry or anyone who wants to learn more about climate system
chemistry.
Berlin and Cottbus, November 2010 Detlev Möller
List of principal symbols
a albedo, radius of particles F Faraday constant
a acceleration f force
a surface of particles f free energy (Helmholtz energy)
ads adsorption (index) G molar free enthalpy
ap apparent (index) (Gibbs energy)
aq aqueous (index) g gravity constant
Acy acidity g gaseous (index)
α dissociation degree g free enthalpy (Gibbs energy)
α Bunsen absorption coefficient Γ transport coefficient
α mass accommodation process Γ surface excess
s
β Ostwald’s solubility γ surface tension
C molar heat capacity at γ uptake coefficient
p
constant pressure H Henry coefficient
C molar heat capacity at H molar enthalpy
V
constant volume H Hammet function
0
c concentration h Planck’s constant
c velocity of light h (reference) height
c number concentration het heterogeneous (index)
N
chem chemical conversion (index) I electric current
coll collision (index) i specific component or particle
D diffusion coefficient (index)
d diameter J emittance
d diffusion (index), see also diff j photolysis rate
des desorption (index) K equilibrium constant
diff diffusion (index) K cryoscopic constant
f
dry dry deposition (index) K Knudsen number
n
E energy K turbulent vertical diffusion
z
E radiant flux, irradiance coefficient
E electrical potential k Boltzmann constant
E activation energy k reaction rate constant
A
e molecular electric charge k mass transfer coefficient
g
ε emission of light κ coefficient for absorption (a)
ε general physical quantity or scattering (s)
ε fraction (0…1) of scavenged κ von Kármán constant
(washout) aerosol particles in L radiance
air l mean-free path
eff effective (index) LWC liquid water content
F flux λ wave length
F molar free energy (Helmholtz λ scavenging coefficient
energy) M mole mass
M third body rxn reactive or reaction (index)
m mass RH relative humidity
m molality ρ density
m mass of molecule ρ mass density
m m
µ chemical potential S salinity
N number (of objects or S molar entropy
subjects) S actinic flux
N Avogadro constant S total particle surface per
A
N(r) cumulative number size volume of air
distribution S solar constant
0
n mole number Sc Schmidt number
n Loschmidt constant sol solution or dissolved (index)
0
n(r) differential number size S saturation ratio
distribution σ Stefan-Boltzmann constant
η number density σ absorption cross section
η dynamic viscosity T temperature
0 zero – reference concerns time t time
or distance (index) τ residence time
2 index for standard conditions τ shear stress
ν frequency τ characteristic time
c
ν kinematic viscosity τ turnover time
t
Ω steariant θ solar zenith angle
P radiant power θ surfacecoveragedegree(0…1)
p pressure U molar inner energy
p area u wind speed
p particulate (index) u friction velocity
*
q square (surface) V volume
Φ quantum yield V molar volume
m
ϕ azimuth angle υ velocity
ϕ fluidity υ dry deposition velocity
d
R rate W (molar) work
R precipitation amount wet wet deposition (index)
R gas constant Q (molar) heat
r rainfall rate x mixing ratio
r correlation coefficient x displacement (horizontal)
r resistance y displacement (horizontal)
r aerodynamic resistance z displacement (vertical)
a
r quasi-laminar resistance z collision number
b
r surface resistance z number of elementary charges
c
rem removal (index) z roughness length of the
0
rev reversible (index) surface
Contents
1 Introduction...................................................... 1
1.1 Airandatmosphere−amultiphaseandmulti-componentsystem ........ 1
1.2 Chemistryandenvironmentalresearch ............................... 6
1.3 Ahistoricalperspectiveofair,waterandchemistry..................... 12
1.3.1 From Antiquity to the Renaissance: Before the discovery of the air
composition...................................................... 12
1.3.2 Discoveryoftheairandwatercomposition........................... 16
1.3.3 Discoveryoftracesubstancesinair.................................. 20
1.3.4 Dustandacidrain:Airpollution.................................... 22
2 Chemicalevolution ................................................ 27
2.1 Thepre-biologicalperiod........................................... 28
2.1.1 Originofelements,moleculesandtheearth........................... 28
2.1.2 Originoforganicbondedcarbon.................................... 37
2.1.2.1 Whatisorganicchemistry?......................................... 38
2.1.2.2 Originofcarbon.................................................. 40
2.1.3 Originofnitrogen................................................. 46
2.2 Evolutionoftheatmosphere........................................ 48
2.2.1 Degassingoftheearth:Theformationoftheatmosphere ............... 49
2.2.1.1 Volcanicgases.................................................... 49
2.2.1.2 Gasesoccludedandproducedfromrocks............................. 52
2.2.1.3 Thepre-biologicalprimitiveatmosphere.............................. 57
2.2.2 Biosphere-atmosphereinteraction.................................... 62
2.2.2.1 Originoflife..................................................... 62
2.2.2.2 Theriseofoxygenandozone:Biogeochemicalevolution................ 67
2.2.2.3 Photosynthesis:Non-equilibriumredoxprocesses ...................... 74
2.2.2.4 Ashorthistoryofunderstandingofphotosynthesis .................... 81
2.2.2.5 Thecarbonandoxygenpoolsandglobalcycling....................... 85
2.2.2.6 Lifelimitsbycatastrophicevents:Massextinction ..................... 93
2.3 Theearth’senergysources.......................................... 94
2.3.1 Solarradiation ................................................... 95
2.3.1.1 Thesunanditsradiationoutput .................................... 95
2.3.1.2 Solarradiationtransferthroughtheatmosphere ....................... 96
2.3.2 Absorptionandemissionoflight.................................... 102
2.3.2.1 Absorption(Lambert-Beerlaw) ..................................... 103
2.3.2.2 Emission(Planck’slawandStefan-Boltzmann’slaw).................... 104
2.3.3 Terrestrialradiationandradiationbudget............................. 106
2.3.4 Geothermalenergy................................................ 108
2.3.5. Renewableenergy................................................. 110
2.3.5.1 Windenergy ..................................................... 110
2.3.5.2 Waterenergy..................................................... 111
2.3.5.3 Bioenergy........................................................ 111
2.3.5.4 Comparisonamongearth’senergysources−potentialforhumans........ 114
2.3.6 Abiogenicversusbiogenicformationof“fossilfuels” ................... 116
2.4 Thebiosphereandglobalbiogeochemicalcycles ....................... 117
2.4.1 Biosphereandthenoosphere ....................................... 118
2.4.2 Biogeochemicalcycling:Theprinciples ............................... 123
2.4.3 Globalbiogeochemicalcycles....................................... 127
2.4.3.1 Nitrogen ........................................................ 128
2.4.3.2 Sulfur .......................................................... 132
2.4.3.3 Chlorine ........................................................ 136
2.4.4 Whatistheroleoflifeinearth’sclimatesystem?....................... 141
2.5 Thehydrosphereandtheglobalwatercycle........................... 145
2.5.1 Water:Physicalandchemicalproperties .............................. 146
2.5.1.1 Waterstructure:Hydrogenbond .................................... 147
2.5.1.2 Waterassolvent.................................................. 150
2.5.1.3 Waterpropertiesinrelationtotheclimatesystem...................... 151
2.5.2 Hydrologiccycleandtheclimatesystem.............................. 152
2.5.3 Atmosphericwater................................................ 155
2.5.3.1 Watervapor...................................................... 157
2.5.3.2 Clouds ......................................................... 159
2.5.3.3 Haze,mistandfog................................................ 162
2.5.3.4 Precipitation ..................................................... 163
2.5.4 Dew,frost,rimeandinterception.................................... 165
2.5.5 Soilwaterandgroundwater:Chemicalweathering ..................... 167
2.5.6 Surfacewater:Riversandlakes ..................................... 168
2.5.7 Theoceans....................................................... 170
2.6 Sourcesofatmosphericsubstances................................... 172
2.6.1 Sourcecharacteristics.............................................. 172
2.6.2 Biogenicsources.................................................. 173
2.6.2.1 Vegetationandmicroorganisms(soilsandwaters)...................... 173
2.6.2.2 Animals......................................................... 176
2.6.3 Theoceanassource............................................... 178
2.6.4 Geogenicsources ................................................. 181
2.6.4.1 Soildust......................................................... 181
2.6.4.2 Seasalt.......................................................... 184
2.6.4.3 Volcanismandemanation.......................................... 185
2.6.4.4 Lightning........................................................ 190
2.6.4.5 Biomassburning ................................................. 192
2.6.4.6 Atmosphericchemistry:Secondarysources............................ 198
2.6.5 Anthropogenicsources............................................. 201
2.6.5.1 Fossilfueluse:Theenergyproblem.................................. 202
2.6.5.2 Agriculture:Thefoodproblem...................................... 209
2.6.5.3 Land-usechangeanddeforestation:Thepopulationproblem ............ 212
2.7 Emissionofatmosphericsubstances.................................. 215
2.7.1 Nitrogencompounds.............................................. 219
2.7.1.1 Ammonia(NH ).................................................. 219
3
2.7.1.2 Dinitrogenmonoxide(N O) ........................................ 222
2
2.7.1.3 Nitrogenmonoxide(NO)........................................... 223
2.7.2 Sulfurcompounds ................................................ 225
2.7.2.1 Sulfurdioxide(SO )............................................... 225
2