Transcript Intro to Urban Climate - Cal State LA

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)
TEMP
70
Yr Avg-10
10-Yr Avg
Degrees F
68
'83
Linear(TEMP
Trend
)Linear
'31
66
64
'97
'59
'05
'85
62
'75
'44
60
58
2006
2002
1998
1994
1990
1986
1982
1978
1974
1970
1966
1962
1958
Data: NOAA NWS (Los Angeles/Oxnard)
LA's HEATING UP!!
1954
Year
1950
1946
1942
1938
1934
1930
1926
1922
1918
1914
1910
1906
1902
1898
1894
1890
1886
1882
1878
'94
LA Civic Center (USC Campus)
Annual Mean Temperature (1878-2007)
70
'83
TEMP
Degrees F
68
'97
'59
Year Avg 01
'07
'31
66
'85
64
62
'44
60
'75
LA's HEATING UP!!
'94
18
78
18
83
18
88
18
93
18
98
19
03
19
08
19
13
19
18
19
23
19
28
19
33
19
38
19
43
19
48
19
53
19
58
19
63
19
68
19
73
19
78
19
83
19
88
19
93
19
98
20
03
58
Data: NOAA NWS (Los Angeles/Oxnard)
Year
Bill Patzert/JPL
California
Temperature
Changes (°F)
1950 - 2000
331 Met. Stations
CA Warming Due To:
• Land Use
• Greenhouse Gas
Warming
California’s Extreme Makeover
“How inappropriate to call this planet Earth when it
is quite clearly Ocean.” – Arthur C. Clarke
WHAT CAUSES CLIMATE
CHANGE?
OK! I believe mankind
causes global
Warming!
Very well. Give the
heretic back his
research funding.
Tide Gauge Observations
150
3.2 mm/year
100
2.0 mm/year
MSL (mm)
50
~ 8 inches
(20 cm)
0.8 mm/year
0
= 16,000 cubic miles!!!
-50
Average Rate
~ 1.8 mm/year
(67,000
cubic
km)
-100
1880
1900
1920
1940
Year
1960
1980
2000
[Church and White, 2006]
Sea Level Rise
Malibu’s “sandbagged” Broad Beach.
The once-wide sand strip, swept away
by waves and rising seas.
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.
History of World Population Growth
10000 B.C. to 2150 A.D.
12
Population in Billions
Population Billions
10
8
6
Apollo
4
WW II
2
Development of
Agriculture
0
-10000
-8000
-6000
Gettysburg
-4000
Year
-2000
0
2000
Human Transformation of the Land Surface
The 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
Global
Land Cover
Urbanization
Urbanization
Present
43% of Land Area
Dominated by Agriculture
% of Land Area
Built-up
3 - 6%
World Population
6.5 Billion
•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 NPP
Humans require almost 20% of Earth’s NPP capacity on land
NPP is the “Common Currency” for Climate Change,
Ecological, & Economic Assessment.
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
NPP Lost or Gained (annual)
Due to Urbanization
Going from a pre-urban to a post urban world
Total Reduction
41.5 Mt C
From Ag Lands
25.5 Mt C
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).
M. Imhoff/NASA
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