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GEOGRAPHY 310: URBAN CLIMATOLOGY
THE EARTH SYSTEM
ATMOSPHERE
HYDROSPHERE
CRYOSPHERE
GEOSPHERE
BIOSPHERE
THE CLIMATE SYSTEM
CLIMATE VERSUS WEATHER
Choose which one hurts less.
• Weather: The condition of the atmosphere at any given time and place.
• Climate: A description of average weather conditions.
Often, it is defined by statistical weather information such as average temperature or average total precipitation.
CLIMATE NORMAL
How Big Is Climate?
Temporal Aspects of Climate:
Climate Variability
Climate Change
Los Angeles Civic Center (USC Campus)Average Annual Temperature (1878-2007)
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Deg
rees
F
TEMP
Yr Avg-10
) Linear(TEMP
'97'83
'05'31
'59
'44 '75
'94
'85
Data: NOAA NWS )Los Angeles/Oxnard(
LA's HEATING UP!!
10-Yr AvgLinear Trend
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70TEMP
Year Avg 10
'97'83
'07'31
'59
'44'75
'94
'85
LA's HEATING UP!!
LA Civic Center (USC Campus)LA Civic Center (USC Campus)Annual Mean Temperature (1878-2007)Annual Mean Temperature (1878-2007)
Data: NOAA NWS (Los Angeles/Oxnard) Bill Patzert/JPLYear
Deg
rees F
CA Warming Due To: • Land Use • Greenhouse Gas Warming California
TemperatureChanges (°F)1950 - 2000331 Met. Stations
California’s Extreme Makeover
““How inappropriate to call this planet Earth How inappropriate to call this planet Earth when it is quite clearly Ocean.” – Arthur C. when it is quite clearly Ocean.” – Arthur C.
ClarkeClarke
WHAT CAUSES CLIMATE CHANGE?
Very well. Give the heretic back his research funding.OK! I believe mankind
causes global Warming!
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1880 1900 1920 1940 1960 1980 2000
MS
L (
mm
)
Year
Tide Gauge Observations
Average Rate ~ 1.8 mm/year
0.8 mm/year
2.0 mm/year
3.2 mm/year
[Church and White, 2006]
~ 8 inches(20 cm)
= 16,000 cubic miles!!!
(67,000 cubic km)
Malibu’s “sandbagged” Broad Beach.
The once-wide sand strip, swept away by waves and rising seas.
Sea Level Rise
To overturn the world economy based on the
musings of a few idiot leftist scientists is just
stupid, that’s what Global Warming is all about.
-Rush Limbaugh-
Typical Surface Weather Map
Climate change
• Climate is defined as the statistical properties of the atmospheric variables like temperature, precipitation, and wind.
• So, climate change can be defined as any change in some statistical property like mean temperature.
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History of World Population Growth10000 B.C. to 2150 A.D.
Population in Billions
Pop
ula
tion
B
illion
s
Year
Apollo
WW II
Gettysburg
Development of Agriculture
Human Transformation of the Land SurfaceThe current land surface little resembles what existed 100,000 years or even 3,000 years ago
• Fire for ecosystem management• Grazing• Deforestation metal smelting• Agriculture• Urbanization
UrbanizationUrbanizationGlobal Land CoverGlobal Land CoverUrbanizationUrbanization
PresentPresent
World Population6.5 Billion
% of Land Area Built-up3 - 6%
43% of Land Area Dominated by Agriculture
•Current U.S. Urban Growth Rate is ~12.5%
•Nearly 50% of the World’s Land Surface has been transformed by human action
•80% of U.S. Population Lives in Urban areas
•60%-80% of World’s Population in urban areas by 2025
Urban Areas and the Climate System
Can you find the Cities?
Why do cities appear this way in this thermal satellite image?
Earth’s “Bio-Engine”Net Primary Production (NPP)
NPP is the amount plant material produced on Earth.
It is the primary fuel for Earth’s food web.Represents all available food and fiber.
NPP can be measured in terms of Carbon (photosynthesis - CO2 exchange between atmosphere and biosphere (global climate change).
Land use strongly impacts NPPHumans require almost 20% of Earth’s NPP capacity on land
NPP is the “Common Currency” for Climate Change, Ecological, & Economic Assessment.
NPP Lost or Gained (annual) Due to Urbanization
Going from a pre-urban to a post urban world
Consequences of Urbanization on NPP-Carbon in the U.S.
Urbanization and NPP - NPP decreased 41.5 M tons C / year.- Roughly equivalent to the increase created by 300 years of agricultural development.
How can this happen when urban areas occupy only 3% of the land surface and agriculture occupies
29%?
Location, Location, Location.Urbanization is taking place on the
most fertile lands
Reduction of NPP may have biological significance:
-Annual loss of food web energy 400 Trillion kilocalories (roughly equal to food energy requirement for 448 million people).- Reduction of actual food products equivalent to needs of 16.5 million persons annually (about 6% of US population).
Total Reduction41.5 Mt C
From Ag Lands25.5 Mt C
M. Imhoff/NASA
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04_T02.JPG
