Constructed climates : a primer on urban environments

283 Pages·2011·8.214 MB·English

by  Will Wilson

Constructed Climates

Constructed Climates
a primer on urban environments
William G. Wilson

the university of chicago press • chicago and london
WilliamG.WilsonisassociateprofessorofbiologyatDukeUniversity.AfterearningaPh.D.inphysics
attheUniversityofHawai’iatManoa,postdoctoralstudiestookhimtotheUniversityofCalgaryandthe
UniversityofCaliforniaatSantaBarbara,whereheturnedtowardproblemsintheoreticalevolutionary
ecology.Hiscurrentfocusisonenvironmentalissuessurroundinghuman-alteredlandscapes.
TheUniversityofChicagoPress,Chicago60637
TheUniversityofChicagoPress,Ltd.,London
©2011byWilliamG.Wilson
Allrightsreserved.Published2011
PrintedintheUnitedStatesofAmerica
20191817161514131211 12345
ISBN-13:978-0-226-90145-9 (cloth)
ISBN-13:978-0-226-90146-6 (paper)
ISBN-10:0-226-90145-9 (cloth)
ISBN-10:0-226-90146-7 (paper)
LibraryofCongressCataloging-in-PublicationData
Wilson,WilliamG.1960–
Constructedclimates:aprimeronurbanenvironments/WilliamG.Wilson.
p. cm.
Includesbibliographicalreferencesandindex.
ISBN-13:978-0-226-90145-9(cloth:alk.paper)
ISBN-10:0-226-90145-9(cloth:alk.paper)
ISBN-13:978-0-226-90146-6(pbk.:alk.paper)
ISBN-10:0-226-90146-7(pbk.:alk.paper)1.Urbanecology(Biology)2.Urbanclimatology.
3.Environmentalhealth.I.Title.
QH541.5.C6W552011
577.5(cid:2)6—dc22
2010021763
(cid:3)∞The paper used in this publication meets the minimum requirements of theAmerican National
Standard for Information Sciences — Permanence of Paper for Printed Library Materials, ANSI
Z39.48-1992.
ToMomandDad,
whoexperiencedallthe
challengesofafamilyfarm

Contents
Preface v
1 CitiesandNature 2
Humanpopulationincreasedsixfoldoverthelastcentury. . . . . . 4
Water, warmth, and light make plants grow. . . . . . . . . . . . . 6
High evapotranspiration promotes biodiversity. . . . . . . . . . . 8
Humansexceedthenaturalpopulationdensityfortheirbodysize. 10
Thelastcenturybroughtincreasedagriculturalefficiency. . . . . . 12
Fossil-fuel-based nitrogen production increased crop yields. . . . 14
Urban land use grew as small farms disappeared. . . . . . . . . . 16
Citieschangeecologicalcommunities. . . . . . . . . . . . . . . . 18
Agriculturalandurbanlandusereducestreamwaterquality. . . . . 20
Impervioussurfacesinurbanizedwatershedshurtorganisms. . . . 22
Durhamrainfallexceedsregulatedbasinsizes. . . . . . . . . . . . 24
Reservoirsreducesedimentswhileprovidingwater. . . . . . . . . 26
2 ShadingandCooling inCityClimates 28
LowvegetationcorrelateswithhightemperatureinDurham. . . . 30
LowvegetationcorrelateswithhightemperatureinIndianapolis. . 32
Lowtemperaturecorrelateswithhighvegetation. . . . . . . . . . 34
Urban heat islands spawn thunderstorms. . . . . . . . . . . . . . 36
Cities change rainfall patterns. . . . . . . . . . . . . . . . . . . . 38
Lightningstrikesreflecturbanweatherchanges. . . . . . . . . . . 40
Citiesgrowwarmer. . . . . . . . . . . . . . . . . . . . . . . . . . 42
Closed-in urban areas have higher heat islands. . . . . . . . . . . 44
TheurbanheatislandmaybeweakwhileEarthwarms. . . . . . . 46
Equalheatcontainedinair,asprinklingofwater,
andanasphaltroad. . . . . . . . . . . . . . . . . . . . . . . . . . 48
Whiter surfaces are cooler. . . . . . . . . . . . . . . . . . . . . . 50
ii CONTENTS
Parking lot trees could provide shade. . . . . . . . . . . . . . . . 52
Big trees could provide lots of shade. . . . . . . . . . . . . . . . 54
Bigger and younger trees transpire more water. . . . . . . . . . . 56
Trees near asphalt stop transpiring early in the day. . . . . . . . . 58
Evapotranspiration is high from watersheds and lawns. . . . . . . 60
Newdevelopmentscanplanforshade. . . . . . . . . . . . . . . . 62
Pavingandgrasscanbecombined. . . . . . . . . . . . . . . . . . 64
3 EnergyUseandCarbonBudgets 66
U.S.energysourceshavechanged. . . . . . . . . . . . . . . . . . 68
States vary in their gasoline and electricity use. . . . . . . . . . . 70
Percapitaenergyusedependsonastate’spopulationdensity. . . . 72
Economicproductivitycorrelateswithenergyuse. . . . . . . . . . 74
Photosynthesis links carbon, water, nitrogen, and sunlight. . . . . 76
AtmosphericCO increasedwithhumanemissions. . . . . . . . . 78
2
Global warming changes nature. . . . . . . . . . . . . . . . . . . 80
Species have different features in urban and rural environments. . 82
Soilscontributetocarbonbudgets. . . . . . . . . . . . . . . . . . 84
Vegetationstoresandsequesterscarbon. . . . . . . . . . . . . . . 86
Urbanpruningcanbeveryintensive. . . . . . . . . . . . . . . . . 88
Carboncostsoflandscapingmachinesarehigh. . . . . . . . . . . 90
Durham citizens export their carbon sequestration. . . . . . . . . 92
Treesandwhitepaintreduceenergyconsumption. . . . . . . . . . 94
Trees help small houses keep cool and break even for heating. . . 96
Wood has low energy content. . . . . . . . . . . . . . . . . . . . 98
Durhamcitizensusemoreenergy than local forests canprovide. . 100

4 EmissionsandUrbanAir 102
Humansourcesof volatile organiccompounds(VOCs)arehigh. . 104
Fossil-fuel use produces many pollutants. . . . . . . . . . . . . . 106
TreesproduceVOCs. . . . . . . . . . . . . . . . . . . . . . . . . 108
VOCsproducedbytreesvaryacrossthecontiguousUnitedStates. 110
TreesproducemoreVOCsinbrightlightandhighheat. . . . . . . 112
VOCsourcesvaryinplaceandtime. . . . . . . . . . . . . . . . . 114
VOCs,reactivenitrogen,andsunlightleadtoground-levelozone. 116
Largepollutioninputsleadtohigh downwind ozone levels later. . 118
Ozoneproductionandlevelshaveacomplicatedemissions
dependence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120
CONTENTS iii
HighozonelevelsseenWednesdaythroughSaturday,March
through September. . . . . . . . . . . . . . . . . . . . . . . . . . 122
Ozoneinruralareasincreaseswithtemperatureandnitrogen. . . . 124
Whenit’shot,urbanozonelevelsexceedregulatoryallowances. . 126
Highozonelevelsharmvegetation.. . . . . . . . . . . . . . . . . 128
Airpollutionvariesgreatlyinspaceandtime. . . . . . . . . . . . 130
5 SocialAspectsofUrbanNature 132
What’s the value of Chickpea? . . . . . . . . . . . . . . . . . . . 134
S.A.Forbes(1880)estimatesthevalueofbirds. . . . . . . . . . . 136
Trees make satisfying neighborhoods. . . . . . . . . . . . . . . . 138
Peoplelikeneattrees,notmessyforests. . . . . . . . . . . . . . . 140
Parkfeaturesinvolvingscenicbeautyandperceivedsecurity. . . . 142
Underbrushwasbadasfarbackas1285. . . . . . . . . . . . . . . 144
About 10 out of 10 people prefer malls. . . . . . . . . . . . . . . 146
VaryingtreecoverinChicagopublichousing. . . . . . . . . . . . 148
Reduced vegetation correlateswithhighercrime. . . . . . . . . . 150
Girls’self-discipline develops better with nature. . . . . . . . . . 152
Naturepromotesemotionalandphysicalhealth. . . . . . . . . . . 154
Treespromotebirdandplantspeciesrichness. . . . . . . . . . . . 156
6 HumanHealthandUrbanInequities 158
Heat waves lead to deaths a few days later. . . . . . . . . . . . . 160
Particulate matter is bad for older people. . . . . . . . . . . . . . 162
Highozoneand SO levelspredicthighasthmahospitalizations. . 164
2
Asthmaincidenceandpollutionaren’ttightlycorrelated
throughtime. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Thoughcitiesdiffer,heatkillspeopleinJulyandAugust. . . . . . 168
Air conditioning reduces heat-related mortality. . . . . . . . . . . 170
Manypeopledieinwinter(accountingforage,race,andgender). 172
Lower income, fewer trees, and higher temperatures go together
in Durham. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174
Wealth,homeownership,andtreesconnectinMilwaukee,
Wisconsin.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176
Wealth,education,andvegetationcorrelateinBaltimore,
Maryland. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178
Parks, trees, andplantscomewithwealth. . . . . . . . . . . . . . 180
Minority populations have worse air, income, and asthma. . . . . 182
Healthier neighborhoods are usually wealthierneighborhoods. . . 184
Incomehelpseducationandincreaseslifeexpectancy. . . . . . . . 186