Minnesotans For Sustainability©

 

Sustainable:  A society that balances the environment, other life forms, and human interactions over an indefinite time period.

 

 

 

Sprawl in California

A report on quantifying the role of the state’s population boom*

Leon Kolankiewicz and Roy Beck
August 13, 2000

[Parts 6 to Endnotes]

 

Table of Contents
6. California Findings
6.1 Population growth related to 100% of sprawl in most cities
   
Table 2
6.2 Los Angeles suggests limits of ‘the denser the better’ approach
  
 
Smart Growth Honor No. 1
  
Smart Growth Honor No. 2

7. Conclusion
Appendix A: California Urbanized Areas raw data
   
Table 3a
   Table 3b

Appendix B: The Census Bureau’s Urbanized Areas data
Appendix C: Calculating per capita land consumption
Appendix D: The Holdren apportioning methodology
   
Table 4
Appendix E: Accounting for distortions by aggregate data
   
Table 5
Appendix F: Population growth without sprawl
About the Authors
Endnotes

 

6. California Findings

We applied the apportioning methodology to the 28 California Urbanized Areas identified by the Census Bureau before 1990.

In the table that follows, the first and second columns of figures show how much rural land was consumed and converted into urban land during the period studied. [Cities with data in the 1980-1990 column were designated Urbanized Areas for the first time in 1980. The fact that there are two different lengths of study does not alter the comparisons of percentages in the two right-hand columns. And where the Census Bureau combined Urbanized Areas during the period of the study, data were adjusted so that comparisons are accurate.]

Read the table like this, using the first line of the table as an example:

1)     The total Antioch-Pittsburgh Urbanized Area sprawled out during the 10-year period covered by Census figures and consumed 35.5 square miles of rural land, converting it into urban land.

2)     67% of that 35.5-square-mile Overall Sprawl was related to the population growth in the Urbanized Area.33% of that 35.5-square-mile Overall Sprawl was related to Per Capita Sprawl (growth in per capita land consumption).

3)     The actual percentages of population growth and of Per Capita Sprawl are not included in this table. [Find them in Tables 1a and 1b.]

6.1. Population growth related to 100% of sprawl in most cities

The results of the comparisons are dramatic. Far from being an insignificant factor in California’s mass sprawl, population growth is related to the overwhelming majority of that sprawl.

The unadjusted analysis showed the population growth share of sprawl to be 100% in 22 of the 28 Urbanized Areas. What this means is that in those cases, between 1970-90 or 1980-90, there was no increase in per capita land consumption in the Urbanized Area as a whole. [In Table 2, we adjusted three of the 22 to lower proportions for reasons explained in Appendix E, so that after adjustment, 19 Urbanized Areas display 100% shares of sprawl related to population growth.]
 

Table 2

 

Urbanized Area

 Sprawl in Square Miles

1970-1990       1980-1990

% of Total Sprawl related to Population Growth
was

% of Total Sprawl related to Growth In Per Capita Land Consumption
was

Antioch-Pittsburg

 

35.5

67%

33%

Bakersfield

41.1

 

99%

1%

Chico

 

7.6

100%

0%

Fairfield

 

8.7

100%

0%

Fresno

53.6

 

100%

0%

Hemet-San Jacinto

 

15.6

100%

0%

Lancaster-Palmdale

 

37.9

100%

0%

Los Angeles1

393.8

 

100%

0%

Modesto

17.8

 

100%

0%

Napa

 

2.0

70%6

30%

Oxnard–Ventura

45.6

 

100%

0%

Palm Springs

 

26.7

100%

0%

Redding

 

16.5

100%

0%

Riverside–San Bernardino

150.4

 

100%

0%

Sacramento2

89.7

 

100%

0%

Salinas

19.7

 

80%

20%

San Diego3

309.5

 

100%

0%

San Francisco-Oakland4

193.1

 

78%

22%

San Jose5

61.2

 

100%

0%

Santa Barbara

11.7

 

78%6

22%

Santa Cruz

 

24.7

74%

26%

Santa Maria

 

2.3

100%

0%

Santa Rosa

29.0

 

100%

0%

Seaside-Monterey

23.4

 

52%

48%

Simi Valley

22.1

 

100%

0%

Stockton

27.0

 

84%6

16%

Visalia

 

2.6

100%

0%

Yuba City

 

1.7

100%

0%

Total

1,670.5

95%

5%

Data sources: 1970 Census of Population, Volume 1 – Characteristics of the population, Part 1 – United States Summary, Table 20 – Population and Land Area of Urbanized Areas, 1970 and1960 (issued June, 1973); 1980 Census of Population, Number of Inhabitants, United States Summary, Table 34 – Population, Land Area, and Population Density of Urbanized Areas: 1980; 1990 Census of Population and Housing, Summary Population and Housing Characteristics, United States, Table 8 – Land Area and Population Density: 1990.
1. Includes
Anaheim, Burbank, Long Beach, Pasadena, Pomona, and Santa Ana.
2.
Roseville added to Urbanized Area in 1990.
3.
Escondido added to Urbanized Area in 1990.
4. Includes Vallejo; Berkeley and Livermore added to Urbanized Area in 1990.
5.
Palo Alto added to Urbanized Area in 1990.
6. Adjusted down from 100%; see explanation in Appendix B.
 

Vast amounts of some of the most scenic, fertile and biologically diverse land in the country were urbanized in those 19 areas. Nonetheless, that population growth is related to 100% of sprawl for so many California cities is a sign of some success in meeting Smart Growth “densification” goals, in that it means every one of those 19 Urbanized Areas succeeded in stopping increases in the per capita consumption of land. In most cases, the per capita consumption of land not only stopped growing but was reduced. Thus, an increase in per capita land use did not account for any sprawl.

Those 19 areas are stark reminders of the limitation of current anti-sprawl and Smart Growth efforts. Their tools for fighting sprawl are woefully inadequate because they do not address population growth. Although they met their goal of stopping Per Capita Sprawl, Overall Sprawl has been rampant in most of those cities.

For example, Simi Valley encroached on another 22 square miles of rural land between 1970 and 1990. The losses were 45 square miles in Oxnard-Ventura, 53 in Fresno, 61 in San Jose, and 89 in Sacramento. Palm Springs paved over nearly 27 square miles in the 1980s alone.

For some smaller Urbanized Areas, the Overall Sprawl in actual square miles may look relatively insignificant compared to that of the large cities. But the percentage sprawl in most of those was quite large, usually running well over 25 percent.

Whether the sprawl was 19 miles (as in Salinas), or 41 miles (as in Bakersfield), or 150 miles (as in Riverside-San Bernardino), some of the finest agricultural land in the world was lost forever under the asphalt and concrete of the expanding cities.

Those 19 Urbanized Areas provide conclusive evidence that simply stopping the growth in per capita land consumption will not stop sprawl.

6.2. Los Angeles suggests limits of ‘the denser the better’ approach

To stop sprawl in the face of continuing population growth, a city would have to force major increases in density on its residents. But no city has shown anywhere near the political will to regiment and restrict its inhabitants sufficiently to accommodate population growth without sprawl.

One of the chief examples of failure is the de facto champion of “densification” –Los Angeles. The designation of Los Angeles as a kind of Smart-Growth model may seem incongruous to many because of its reputation as the “sultan of sprawl” and “suburbs in search of a city.” For many Americans, Los Angeles is a sprawling model of what they don’t want their city to become. But, indeed, the Los Angeles Urbanized Area earned quantitative Smart Growth honors between 1970 and 1990.

One of the chief ideas behind Smart Growth initiatives is that denser is better. Nearly all Smart Growth policies are based on the concept that a city’s population can continue to grow indefinitely without creating a lot of sprawl.

That can happen in only one way: by confining more and more people into existing urbanized areas. You know that Smart Growth efforts are reaching one of their major goals when you see density increasing. The city that packs the most people into each square mile gets the prize. Under those measures, the champion model of Smart Growth in the entire nation since 1970 was none other than Los Angeles.

Smart Growth Honor No. 1:

Unlike most American Urbanized Areas (but similar to most in California), Los Angeles stopped all individual sprawl. That is, the land per resident did not expand. In fact, the urban land per resident shrank by 8%. That means the density increased. From 5,313 residents per square mile in 1970, Los Angeles squeezed in another 500 people per square mile by 1990. Moreover, Smart Growth was achieving its goal throughout the Urbanized Area; density increased in both the core city and in the suburbs.

Smart Growth Honor No. 2:

By 1990, land consumption per L.A. resident had dropped to 0.11 acre. That made Los Angeles the most densely populated Urbanized Area in America. No other urban area -not even New York- provided so little land per resident.8 This is a model that Smart Growth planners apparently would wish for all Americans, certainly if the U.S. population continues to grow.

The fact that Los Angeles on paper deserves Smart Growth accolades raises two important questions:

(1) Has the increased density improved the quality of life of those who live there?

(2) Has the increased density stopped sprawl?

The first question is a complex one that is outside the scope of this study. Certainly, though, there are indicators that the increased density is related to several major causes of social stress and frustration in Los Angeles, such as overcrowded schools and traffic snarls. Retrofitting a city to accommodate high-density living is very difficult and expensive at best and probably impossible in reality. An example would be the massive problems and expense associated with recent attempts to build a subway to serve even a tiny fraction of Los Angeles. Often, increased density results in a more congested quality of life. And congestion is a result no one is seeking.

The second question is easy to answer; Census Bureau calculations show that increasing the density in Los Angeles did not stop sprawl. Between 1970 and 1990, urban Los Angeles sprawled across an extra 394 square miles (252,160 acres). This was in addition to the 1,572 square miles it already occupied in 1970. Only five other Urbanized Areas in the entire country sprawled more than Los Angeles during this time period. That’s hardly a model of success in combating the sprawl problem.

What accounted for this sprawl? Population growth, pure and simple. Between 1970 and 1990, the L.A. Urbanized Area grew by 3.1 million residents –largely because of the federal program of increased immigration levels and the inadequacy of federal efforts to curb illegal immigration. All those additional people had to live, work, play, commute, and be educated somewhere.

Although they and the existing residents were willing and able to crowd more closely together than in the past, they did not choose to live together all in the existing urban area. That would have increased the density another 37% over what already were the densest living conditions that Americans in any Urbanized Area were willing to accept.

The unwillingness to further crowd themselves into an ever-denser Los Angeles may have been related to the nonlinear nature of congestion once density reaches a certain level. For example, once freeways are near their capacities, increasing the number of cars on the road by, say, 37% can increase waiting times, traffic jams, etc., by much more than 37%.

For whatever reasons that residents refused to increase their density enough to accommodate 3.1 million additional residents, the result was the loss of another 394 square miles of orchards, farmland, natural habitat and other open and rural spaces.

Thus, just as Los Angeles is one model for meeting the Smart Growth goal of high-density living, it also is a model of how Smart Growth initiatives are likely to fail to stop sprawl under current federal policies that generate population growth.

Other models of increasing density but continuing major sprawl were Riverside-San Bernardino, which converted another 150 square miles of rural land into urbanized land, and San Diego, which consumed 309 additional square miles. Only five California Urbanized Areas exhibited the overall American tendency to increase the urban land required for each resident. Per Capita Sprawl was related to 20% of Overall Sprawl in Salinas, 22% in San Francisco-Oakland, 26% in Santa Cruz, 33% in Antioch-Pittsburg, and 48% in Seaside-Monterey.
 

7.  Conclusion

Summing the entire area of Overall Sprawl from the 28 Urbanized Areas, one finds 1,670.5 square miles of rural land lost to sprawl. The average share of sprawl in California Urbanized Areas explained by population growth was about 95%.

California’s cities, for the most part, stopped the trend of increasing per capita urban land use. Population growth in most California cities is now the only sprawl-inducing factor that is increasing.

More than any other ingredient, it is the overall growth of U.S. population that is most responsible for the population growth driving sprawl in California’s Urbanized Areas. Between 1950 and 2000, the population of the United States rose from about 150 million to 275 million. A disproportionate part of that growth occurred in California, which tripled its population during that period.

Between 1970 and 1990, the period of analysis, California’s population rose from 20 to 30 million, accounting for 10 million of the 45-million national increase.

According to the Census Bureau, if current trends of American fertility rates and federal immigration policies continue, California is on a course to hit 50 million residents in 2025. At that point, Californians will be living more densely than today’s residents of China.

Nothing that has occurred in California’s cities thus far suggests that –if federal policies driving national population growth continue– sprawl will not continue its march across California’s ever-more beleaguered rural and open spaces well beyond the year 2025. In the process, the state’s environment and quality of life for residents will pay an ever-higher price for the nation’s unwillingness to stabilize its population.

These population policies, phenomena and trends –as has been shown by this study– are central to understanding the future of sprawl in California. Studies and plans from state commissions, think tanks, universities and advocacy groups that purport to offer blueprints for combating sprawl without talking about dealing with population growth look either naïve, foolish or deceptive in light of the findings of this study.

We began this investigation to test whether a common sense perception (that California’s population explosion is a major factor in its rampant sprawl) could be quantified as true. That perception had been thrown into doubt by the treatment of population growth as a non-factor in sprawl by myriad activists, journalists, planners and politicians.

This study has provided the quantitative evidence in support of the common sense perception:

Population growth obviously is the No. 1 factor related to California’s deplorable sprawl problem.

 

Appendix A: California Urbanized Areas Raw Data

Table 3a

1970-1990 California Urbanized Areas Raw Data
Population, per capita land use and total land area
from 1970 and 1990 U.S. Census Bureau reports

 
Urbanized Area

 
1970 Population

 
1990 Population

 1970
Per Capita
Land Use

(acres/person)

 1990
Per Capita
Land Use

(acres/person)

 1970
Total
Land Area

(sq. miles
)

1990
Total
Land Area

(sq. miles)

Bakersfield

176,155

302,605

0.2078

0.2079

57.2

98.3

Fresno

262,908

453,388

0.1926

0.1873

79.1

132.7

Los Angeles1

8,351,266

11,402,946

0.1205

0.1103

1571.9

1965.7

Modesto

106,107

230,609

0.2069

0.1446

34.3

52.1

Oxnard–Ventura

244,653

480,482

0.2917

0.2093

111.5

157.1

Riverside-San Bernardino

583,597

1,170,196

0.3396

0.2516

309.7

460.1

Sacramento2

633,732

1,097,005

0.2466

0.1948

244.2

333.9

Salinas

62,456

122,225

0.1537

0.1817

15.0

34.7

San Diego3

1,198,323

2,348,417

0.2033

0.1881

380.7

690.2

San Francisco-Oakland4

2,987,850

3,629,516

0.1459

0.1541

681.0

874.1

San Jose5

1,025,273

1,435,019

0.1730

0.1509

277.2

338.4

Santa Barbara

129,774

182,163

0.1830

0.1715

37.1

48.8

Santa Rosa

75,083

194,560

0.3256

0.2211

38.2

67.2

Seaside-Monterey

93,284

133,188

0.1653

0.2282

24.1

47.5

Simi Valley

56,936

128,043

0.2788

0.2344

24.8

46.9

Stockton

160,373

262,046

0.1868

0.1802

46.8

73.8

Data sources: 1970 Census of Population, Volume 1 – Characteristics of the Population, Part 1 – United States Summary, Table 20 – Population and Land Area of Urbanized Areas, 1970 and1960 (issued June, 1973); 1990 Census of Population and Housing, Summary Population and Housing Characteristics, United States, Table 8 –Land Area and Population Density: 1990.
1. Includes
Anaheim, Burbank, Long Beach, Pasadena, Pomona, and Santa Ana.
2.
Roseville added to Urbanized Area in 1990.
3.
Escondido added to Urbanized Area in 1990.
4. Includes Vallejo; Berkeley and Livermore added to Urbanized Area in 1990.
5.
Palo Alto added to Urbanized Area in 1990 

 

Table 3b

1980-1990 California Urbanized Areas Raw Data
Population, per capita land use and total land area
from 1980 and 1990 U.S. Census Bureau reports

 
Urbanized Area

 
1980
Population

 
1990
Population

 1980
Per Capita
Land Use

(acres/person)

 1990
Per Capita
Land Use

(acres/person)

 1980
Total
Land Area

(sq. miles)

 1990
Total
Land Area

(sq. miles)

Antioch-Pittsburg

86,435

 

153,768

0.1925

0.2560

26.0

61.5

Chico

51,914

71,831

0.3082

0.2905

25.0

32.6

Fairfield

69,255

99,964

0.2957

0.2606

32.0

40.7

Hemet-San Jacinto

55,377

90,929

0.3236

0.3069

28.0

43.6

Lancaster-Palmdale2

56,328

187,190

0.5113

0.2834

45.0

82.9

Napa

59,277

68,049

0.2051

0.1975

19.0

21.0

Palm Springs

66,431

129,025

0.6069

0.4450

63.0

89.7

Redding

52,867

78,364

0.5448

0.5023

45.0

61.5

Santa Cruz

123,226

152,355

0.3843

0.4146

74.0

98.7

Santa Maria

57,237

88,989

0.2572

0.1819

23.0

25.3

Visalia

58,957

83,594

0.2714

0.2113

25.0

27.6

Yuba City

61,107

77,167

0.2723

0.2297

26.0

27.7

1980 Census of Population, Number of Inhabitants, United States Summary, Table 34 – Population, Land Area, and Population Density of Urbanized Areas: 1980; 1990 Census of Population and Housing, Summary Population and Housing Characteristics, United States, Table 8 – Land Area and Population Density: 1990.
To convert from acres to square miles, divide by 640. To convert from square miles to acres, multiply by 640.
 

Appendix B: The Census Bureau’s Urbanized Areas Data

Generally speaking, an Urbanized Area must exhibit a pattern of continuous development outward from a central core. Although there are special provisions for “jumps,” and certain other exceptions, by and large, new areas added every 10 years by the Census Bureau to the adjacent urban fringe must be contiguous to that fringe and must have a population density of at least 1,000 people per square mile.

Difference from MSA designation

Urbanized Areas are smaller in area than the Metropolitan Statistical Areas (MSA) that are mentioned far more commonly in the media and other public discussion. The Census Bureau describes an MSA as “a large population nucleus, together with adjacent communities having a high degree of social and economic integration with that core.”9 The major difference between the Urbanized Area and the MSA is that the latter includes the entire land mass of every county that contains a part of a city and its suburbs. That means the outer parts of an MSA are rural.

An Urbanized Area, on the other hand, includes whole counties only if every square mile of them is urbanized. And in the outer counties, only the land that is indeed urbanized is counted. An MSA often lumps together cities that have substantially grown out toward each other but which may still contain some rural land between them. For example, Los Angeles and its contiguous suburbs in Orange and Los Angeles counties, Simi Valley and its suburbs, Oxnard-Ventura and their suburbs, and San Bernardino and Riverside and their suburbs are all classified as a single CMSA (Consolidated Metropolitan Statistical Area). But because there is some rural land remaining between the suburbs of one and the suburbs of another, these places are considered to be four separate Urbanized Areas.

Usefulness as a measuring tool

The 1,000-people-per-square-mile threshold for classification as part of an Urbanized Area is not without its critics. For example, urban expert David Rusk believes that the growth in Urbanized Land Areas since 1950, as documented in successive Census Bureau reports, understates the actual loss of rural environments to sprawl.10 The 1,000 density threshold (equal to about one dwelling per two acres) is arguably too dense to convey a rural “feel” and allow for unfettered rural livelihoods, like farming. On the other hand, there is still a substantial amount of open space left when there is an average of two acres (about two football fields) for each house.

Nonetheless, the practice of designating a given site as either urban or rural, with no intermediate classification, is indeed an oversimplification. Yet for the purposes of this study, shortcomings of the Census designations have little effect on the outcome.

Since this study has defined sprawl as the progressive loss of open space to built-up space –unpaved lands to paved-over ground in other words– the 1,000-per-square-mile criterion is as defensible a threshold between urban and rural zones as any. Moreover, it allows use of the Census Bureau’s nationwide, unrivalled stock of information. The strength of the Census Bureau’s uniform data set lies in calculating changes from rural to urban areas rather than in precisely defining the line that divides them. The shortcoming of the Census Bureau measurement is in calculating total development, not in calculating change. This study focuses on the change.
 

Appendix C: Calculating Per Capita Land Consumption

The per person land consumption in each Urbanized Area can be expressed as:

a = A / P (1)

where:

a = area of urbanized land for the average resident

A = Area of total urbanized land in a city and its suburbs

P = Population of that city and its suburbs

For example, the West Palm Beach Urbanized Area in 1990 had 794,848 residents living on about 196,000 acres. Thus, the per capita land use was around 0.25 acre (one-quarter of an acre) per resident.

Put simply: The land used per person is the total land area divided by the total number of people. This is the inverse of population density, which is the number of people per unit area of land. When per capita land consumption goes up, density goes down; when per capita land consumption goes down, density goes up. Land consumption in most California's Urbanized Areas ranges between one-seventh and one-third of an acre for each resident (see figures in Appendix A).

The total land area occupied by the built-up Urbanized Area can be expressed as:

A = P x a (2)

This can be stated as: the total square miles (or acres) of an Urbanized Area can be simply expressed or “factored” into the product of the Population of the Urbanized Area (viz., P) multiplied by the per capita urban land consumption (viz., a). Equation (2) is the basis for attributing or apportioning the shares of sprawl (viz. growth in A) back onto two contributing factors, the growth in P and the growth in a.
 

Appendix D: The Holdren Apportioning Methodology

A method for quantifying the respective contributions of population growth and changes in consumption per capita of any type of resource consumption was laid out in a landmark 1991 paper by Harvard physicist Prof. John Holdren.11 Although Dr. Holdren’s paper dealt specifically with the role of population growth in rising energy consumption, the method can be applied to many types of population/resource consumption analyses. In the case of sprawl, the resource under consideration is rural land, namely the expansion over time of the Urbanized Area into rural areas.

As stated in Appendix C, the total land area occupied by the built-up Urbanized Area can be expressed as:

A = P x a (1)

Where:

A = Area of total urbanized land in a city and its suburbs

a = area of urbanized land used by the average resident (per capita land use)

P = Population of that city and its suburbs

Following the logic in Holdren’s paper, if over a period of time t (e.g., a year or decade), the population grows by an increment P and the per capita land use changes by a, the total urbanized land area grows by A which is given by substituting in eqn. (1):

A + A = (P + P) x (a + a) (2)

Subtracting eqn. (1) from eqn. (2) and dividing through by A to compute the relative change (i.e., A/A) in urbanized land area over time interval t, yields:

A/A = P/P + a/a + (P/P) x (a/a) (3)

Now eqn. (3) is quite general and makes no assumption about the growth model or time interval. On a year-to-year basis, the percentage increments in P and a are small (i.e., single digit percentages), so the second order term in eqn. (3) can be ignored. Hence following the Holdren paradigm, eqn. (3) states that the percentage growth in urbanized land area (viz., 100% x A/A ) is the sum of the percentage growth in the population (100% x P/P) plus the percentage growth in the per capita land use (100% x a/a ).

Stated in words, eqn. (3) becomes:

Overall percentage land area growth =

Overall percentage population growth + Overall percentage per capita growth (4)

In essence, the Holdren methodology quantifies population growth’s share of total land consumption (sprawl) by finding the ratio of the overall percentage change in population over a period of time to the overall percentage change in land area consumed for the same period. This can be expressed as:

Population share of growth=

(Overall percentage population growth)

        ________________________________    (5)

(Overall percentage land area growth).


The same form applies for per capita land use:

Per cap. land use share of growth =

(Overall percentage per capita land use growth)

           ________________________________             (6)

(Overall percentage land area growth).


The above two equations follow the relationship based on Prof. Holdren’s eqn. (5) in his 1991 paper. A common growth model follows the form (say for population):

P(t) = P0 (1 + gP )t   (7)

Where P(t) is population at time t, P0 is the initial population and gP the growth rate over the interval. Solving for gP the growth rate yields:

ln (1 + gP) = (1/t) ln (P(t)/P0)    (8)

Since ln (1 + x) approximately equals x for small values of x, eqn. (8) can be written as

gP = (1/t) ln (P(t)/P0).   (9)

The same form of derivation of growth rates can be written for land area (A) and per capita land use (a)

gA = (1/t) ln (A(t)/A0)    (10)

ga = (1/t) ln (a(t)/a0).    (11)

These three equations for the growth rates allow you to restate the Holdren result of eqn. (4) as:

gp + ga = gA    (12)

Substituting the formulae (eqns. 9 thru 11) for the growth rates and relating the initial and final values of the variables P, a and A over the period of interest into eqn. (12), the actual calculational relationship becomes:

ln (final population / initial population) +

 ln (final per capita land area / initial per capita land area) =

 ln (final total land area / initial total land area)   (13)

In other words, the natural logarithm (ln) of the ratio of the final to initial population, plus the logarithm of the ratio of the final to initial per capita land area (i.e., land consumption per resident), equals the logarithm of the final to the initial total land area.

In the case of the San Francisco-Oakland Urbanized Area from 1970 to 1990, this formula would appear as:

ln (3,629,516 residents / 2,987,850 residents) +

ln (0.15413 acre per resident / 0.14587 acre per resident) =

ln (874.1 square miles / 681.0 square miles)    (14)

Computing the ratios yields:

ln (1.215) + ln (1.057) = ln (1.284)

0.1950 + 0.0555 = 0.250 (15)

Then applying eqns. (5) and (6), the percentage contributions of population growth and per capita land area growth are obtained by dividing (i.e., normalizing to 100%) each side by 0.250:

0.1950  +  0.0555  =  0.2500

0.2500      0.2500       0.2500   (16)


Performing these divisions yields:

0.78 + 0.22 = 1.0   (17)

Thus, we see that in the case of the San Francisco-Oakland Urbanized Area from 1970 to 1990, the share of sprawl due to population growth was 78% [100 % x (0.1950 / 0.250)], while declining density (i.e., an increase in land area per capita) accounted for 22% [100% x (0.0555 / 0.250)]. Note that the sum of both percentages equals 100%.

In a number of cases (19 out of the 28), the results of the Holdren method showed that population growth actually explained more than 100% of the sprawl that occurred, while the per capita land area growth share was less than 0% (i.e., a negative number due to higher population densities or a decrease in land use per capita). Still in these instances, the sum of the percentage numbers –one positive and one negative– adds up to 100%.

These are the cases in which overall population density increased throughout a given Urbanized Area (i.e. per capita land consumption went down), so that if there had been no population growth, total urbanized land area taken up by that city and its suburbs would have actually declined. In the table shown in Section 6 of this report (California Findings), a conscious decision was made to limit the calculated share of the total growth rate to only 100% of sprawl for population growth and to report 0% as the growth in land consumption per capita in these cases to avoid the confusion of negative growth rates. (After all, the question is what percentage of a fixed number of square miles of sprawl was caused by population growth. In layman's terms, 100% of those fixed square miles is the highest possible number.) Yet, strictly speaking, this means that in some Urbanized Areas, population growth was so great that it simply overwhelmed the decline in per capita land use, thus leading to positive overall sprawl.

Table 4 presents the unadjusted results of the apportioning formula:
 

Table 4

  
Urbanized Area

  
Sprawl in Square Miles 

1970-1990          1980-1990


% of Total Sprawl related to Population Growth
was

% of Total Sprawl related to
Growth In Per Capita Land Consumption
was

Chico

 

7.6

122%

-22 %

Fairfield

 

8.7

153%

-53%

Fresno

53.6

 

105%

- 5%

Hemet-San Jacinto

 

15.6

112%

-12%

Lancaster-Palmdale

 

37.9

197%

-97%

Los Angeles1

393.8

 

139%

-39%

Modesto

17.8

 

186%

-86%

Oxnard–Ventura

45.6

 

197%

-97%

Palm Springs

 

26.7

188%

-88%

Redding

 

16.5

126%

-26%

Riverside–San Bernardino

150.4

 

176%

-76%

Sacramento2

89.7

 

175%

-75%

San Diego3

309.5

 

113%

-13%

San Jose5

61.2

 

169%

-69%

Santa Maria

 

2.3

463%

-363%

Santa Rosa

29.0

 

169%

-69%

Simi Valley

22.1

 

127%

-27%

Visalia

 

2.6

353%

-253%

Yuba City

 

1.7

368%

-268%

Data sources: 1970 Census of Population, Volume 1 – Characteristics of the Population, Part 1 – United States Summary, Table 20 – Population and Land Area of Urbanized Areas, 1970 and1960 (issued June, 1973); 1980 Census of Population, Number of Inhabitants, United States Summary, Table 34 – Population, Land Area, and Population Density of Urbanized Areas: 1980; 1990 Census of Population and Housing, Summary Population and Housing Characteristics, United States, Table 8 – Land Area and Population Density: 1990.
1. Includes
Anaheim, Burbank, Long Beach, Pasadena, Pomona, and Santa Ana.
2.
Roseville added to Urbanized Area in 1990.
3.
Escondido added to Urbanized Area in 1990.
4. Includes Vallejo; Berkeley and Livermore added to Urbanized Area in 1990.
5.
Palo Alto added to Urbanized Area in 1990.
 

Appendix E: Accounting for Distortions by Aggregate Data

We note that our analysis, when applied at the level of the aggregate Urbanized Area, including one or more central places and an urban fringe, may not capture shifting population within urban boundaries. This requires additional measurements to ensure that such hypothetical shifts have not distorted the conclusions.

Hypothetically, it is possible that much or most of an Urbanized Area’s population growth occurred on a small fraction of the already built-up central place (i.e. urban core) or older portions of the urban fringe (i.e. inner suburbs) of the Urbanized Land Area, while a small minority of residents building 4,000 sq. ft. single-family dwellings on half-acre lots actually accounted for most of the increase in urban/suburban land. In such a scenario, the population growth would not be directly responsible for much of the sprawl since all of the population growth was occurring in the core of the city –not on the periphery of the suburbs.

So if an Urbanized Area’s population growth is occurring primarily in the urban core while densities are falling in the suburbs, the proportion of sprawl attributed to population growth may be misleading.

Fortunately, the Census Bureau provides separate data for the urban cores and the suburban fringes. This makes it possible to test for the hypothetical distortion just stated. We have performed the test and found little to indicate that the sprawl our formula has associated with population growth was instead really caused by affluent suburbanites with gluttonous appetites for land.

Our initial analysis relying solely on aggregate data showed the population growth share of sprawl to be 100% in 22 of the 28 Urbanized Areas. What this means is that in those cases, between 1970-90 or 1980-90, the percentage of population growth exceeded the percentage growth in land area. Overall density in the Urbanized Area rose, which means that overall declining density (averaged across the entire UA), by definition, could not have accounted for any sprawl. Yet, it is possible for the urban core density (and population) to rise, while the suburban density falls. In these cases, using only the aggregated population growth and density figures for the entire Urbanized Area would mask the fact that density had declined in the suburbs.

Thus, we examined all those cities in which the mathematical model related 100% of sprawl to population growth at the level of the aggregate Urbanized Area, in order to detect the pattern of change in urban and suburban densities. [We also examined Bakersfield for which 99% of its sprawl was correlated with population growth.]

The sign that population growth really wasn’t that much of a culprit (i.e. linked to 100% of sprawl) would be the meeting of each of two conditions: (1) an increase in urban density, and (2) a simultaneous decrease in suburban density.

Table 5 below shows the results of this analysis:

Table 5

Urbanized Area

Urban
Density

Suburban
Density

Bakersfield

Increased 5%

Increased 4%

Chico

Decreased 6%

Increased 49%

Fairfield

No change

Increased 108%

Fresno

Decreased 10%

Increased 14%

Hemet-San Jacinto

No change

Increased 29%

Lancaster-Palmdale

Decreased 21%

Increased 198%

Los Angeles

Increased 20%

Increased 4%

Modesto

Decreased 16%

Increased 68%

Napa

Increased 12%

Decreased 38%

Oxnard–Ventura

Increased 124%

Increased 12%

Palm Springs

Increased 26%

Increased 54%

Redding

Decreased 10%

Increased 60%

Riverside–San Bernardino

Increased 40%

Increased 36%

Sacramento

Increased 21%

Increased 30%

San Diego

Increased 18%

Increased 1%

San Jose

Increased 19%

Increased 7%

Santa Barbara

Increased 35%

Decreased 13%

Santa Maria

Increased 53%

Increased 17%

Santa Rosa

Increased 9%

Increased 13%

Simi Valley

Increased 24%

Increased 669%

Stockton

Increased 11%

Decreased 23%

Visalia

Increased 36%

Increased 5%

Yuba City

Increased 6%

Increased 200%

 
Thus, it can be seen that of those Urbanized Areas where the original analysis indicated population’s share of sprawl to be 100%, in the case of only three small to moderately large cities –Napa, Santa Barbara, and Stockton– is the result somewhat misleading for the reason just given. Population growth’s share of sprawl in these cities was adjusted accordingly. The Findings Table in Section 6 shows the adjusted percentages rather than the original 100% share attributed to population growth.

In each of those three Urbanized Areas, the per capita land consumption of the total Urbanized Area did not increase.

Thus, the formula originally assigned 0% of the Overall Sprawl to Per Capita Sprawl. But in each of those cases, a strong decrease in per capita land consumption in the urban core disguised the fact that there was significant Per Capita Sprawl in the suburbs.

In the case of Stockton, the central core grew in area from 29.9 to 52.6 square miles from 1970 to 1990 (an increase of 76%), while the fringe or suburbs grew only from 16.9 to 21.2 square miles (a 25% increase). Thus, expansion of Stockton’s urban core was responsible for 84% of the increase in land area for that California city from 1970 to 1990. Within that 84%, population growth had a 100% share of sprawl; within the 16% of Stockton’s total sprawl that was suburban or urban fringe, population growth had a 0% share of sprawl. Thus, overall, 84% of Stockton’s total sprawl was due to population growth.

In the case of Napa, the population had a 100% share of the growth in the size of the urban center from 16.0 to 17.4 square miles, but a 0% share in the growth of the urban fringe from 3.0 to 3.6 square miles. To adjust the percentage, we found that the urban core’s growth in land area constituted 70% of the total growth in land area.

Therefore, because 100% of the sprawl in the urban core was related to population growth, it was determined that population growth comprised 70% of total sprawl in Napa.

Finally, in the case of Santa Barbara, the “central city” or core area actually declined slightly from 1970 to 1990, even as its population and density rose. Thus, it would be inappropriate to assign any of Santa Barbara’s sprawl to this central city population increase (although, as stated above, some flight to the suburbs may indeed have been induced by population-related pressures and problems in the urban core, but we can’t measure or quantify this readily). Therefore, the share of Santa Barbara’s sprawl related to population growth was derived by comparing the change in suburban (i.e. “urban fringe” in Census Bureau terminology) population and land area from 1970-90.

Using this technique, Santa Barbara’s population share of sprawl was 78%.

In 20 of 23 cases above, suburban density was rising during the study period. Thus, there was no widespread shifting of internal populations that rendered the results of the apportioning tool a distortion of reality. Rising density in the suburbs allows one to rule out the possibility that a rapid rise in density in the core (say, driven by the settlement of poor immigrants at very high densities, as happened in Santa Ana in the 1980s and 1990s) could have been so high as to mask declining density in the suburbs.
 

Appendix F: Population Growth Without Sprawl

The apportioning formula shows that 100% of the 393 square miles of sprawl in Los Angeles was associated with population growth. But theoretically, Los Angeles could have had no sprawl at all if every one of the 3.1 million additional residents had settled within the existing urban boundary.

For example, Los Angeles could have avoided sprawl during the study period if the following had occurred:

(1) If all pre-existing residents were forbidden from moving from inside the city to rural land just outside the city. They would have had to remain within the old boundaries of the Urbanized Area or moved inside the boundaries of another city.

(2) If arriving immigrants and residents of other parts of the country were required to settle inside existing city boundaries.

(3) If vacant land inside the urban boundary were used for providing places of work and commerce for the 3.1 million new residents.

(4) If the leftover business, commerce and entertainment needs plus the residential needs of the extra 3.1 million residents were met by a combination of the following: (a) large numbers of pre-existing residents in single-family dwellings would either divide their houses into duplexes or tear down their homes, allow apartment buildings to be built on their land and then move into one of the apartments; (b) the scarce remaining public parks would be converted into apartment  complexes; (c) more low-level apartment buildings would be replaced with high-rises; (d) local teens and people in their early 20s on the verge of household formation would continue living with their parents or double up with someone else already living within the old urban boundaries.

(5) If the 3.1 million residents placed no further demands for non-urban recreation, waste disposal, worksites, shopping or roads just beyond the urban boundary.


Those five requirements would necessitate a level of government control, personal sacrifice, voluntary lifestyle change, loss of personal freedom, and expense that no city in America has come close to talking about –let alone fulfilling. But something that drastic would be needed to force the most densely populated city in
America to increase its density by another 37%. If one were to design a city from scratch, one would be far more likely to achieve such a density with public approval. But, as is obvious from the above five requirements, it is extremely expensive, disruptive and personally difficult to quickly achieve major density enhancements in already-built areas.

The United States provides no models of Urbanized Areas which succeeded in accommodating population growth without sprawl. There were no such successes in the short-term, let alone long-term.

About the Authors

Leon Kolankiewicz and Roy Beck are co-authors of “The Environmental Movement's Retreat from Advocating U.S. Population Stabilization (1970-1998): A First Draft of History,” Journal of Policy History, Vol.12, No.1, 2000 (Pennsylvania State University Press). Leon Kolankiewicz is a national environmental/natural resource planner and a former planner with the Orange County (CA) Environmental Management Agency. He has a B.S. in forestry and wildlife management from Virginia Tech and an M.S. in environmental planning and natural resources management from the University of British Columbia. He has worked as an environmental professional for more than two decades, including stints with the U.S. Fish and Wildlife Service, National Marine Fisheries Service, Alaska Department of Environmental Conservation, Alaska Department of Fish and Game, University of Washington, University of New Mexico, and as a national parks technical advisor with the Peace Corps in Central America. He has written more than 70 articles and reports and is the author of Where the Salmon Come to Die: An Autumn on Alaska's Raincoast (Boulder, Colorado: Pruett, 1993).

Roy Beck is a Washington D.C. public policy analyst and the director of NumbersUSA.com, an Internet organization that tracks the role of each Member of Congress in forcing or reducing U.S. population growth. He is the author of four books on U.S. population, the environment, ethics and politics. His articles have appeared in scores of academic books and publications such as the Atlantic Monthly. A graduate of the University of Missouri School of Journalism, he was one of the nation's first environment-beat newspaper reporters in the 1960s. As Chief Washington Correspondent of the Booth Newspapers chain in the 1980s, he covered some of the decisions by Congress to speed up U.S. population growth. For the past decade, U.S. population issues have been his primary focus of research, writing, and speaking.

Endnotes

1. Norman Myers, et al. 2000. "Biodiversity hotspots for conservation priorities." Nature, vol. 403, p.853. 24 February; R.P. Cincotta, et al. 2000. "Human population in the biodiversity hotspots." Nature, vol. 404 p. 990, 27 April. California is one of the world's 25 biodiversity hotspots and one of the most heavily populated ones at that.
2. U.S. Census Bureau. 1996. "Population Projections for States, by Age, Sex, Race, and Hispanic Origin: 1995 to 2025."
Population Paper Listing #47, Table: Projections of the Total Population of States: 1995 to 2025.
3. See note 1.
4. The U.S. Census Bureau data sources used in this study are:
1990 Census of Population and Housing, Summary Population and Housing Characteristics -- United States, Table 8 – Land Area and Population Density; 1980 Census of Population, Number of Inhabitants, United States Summary, Table 34 – Population, Land Area, and Population Density of Urbanized Areas: 1980; 1970 Census of Population, Volume 1 Characteristics of the Population, Part 1, United States Summary (issued June 1973), Table 20 – Population and Land Area of Urbanized Areas: 1970 and 1960. All of these are available from the Statistical Information Office (Population Division) of the U.S. Department of Commerce’s Bureau of the Census in Maryland (301-457-2422).
5. A CAPS Data Report, Jan. 22, 1999, Californians for Population Stabilization, Los Angeles, (213) 387-6454.
6. Mathis Wackernagel and William Rees. 1996.
Our Ecological Footprint: Reducing Human Impact on the Earth. Gabriola Island, B.C. and Philadelphia, PA: New Society Publishers. The New Catalyst Bioregional Series.
7. John P. Holdren. 1991. “Population and the Energy Problem.”
Population and Environment, Vol. 12, No. 3, Spring 1991. Holdren is Teresa and John Heinz Professor of Environmental Policy and Director of the Program on Science, Technology, and Public Policy at Harvard University’s Kennedy School of Government, as well as Professor of Environmental Science and Public Policy in the Department of Earth and Planetary Sciences at Harvard University. Trained in aeronautics/astronautics and plasma physics at MIT and Stanford, he previously co-founded and co-led for 23 years the campus-wide interdisciplinary graduate degree program in energy and resources at the University of California, Berkeley. On April 12, 2000 he was awarded the Tyler Prize for Environmental Achievement at the University of Southern California, which administers the award. The Tyler Prize is the premier international award honoring achievements in environmental science, energy, and medical discoveries of world-wide importance.
8. Because of the skyscraper density in New York City's Manhattan borough, it is difficult for many to believe the Los Angeles Urbanized Area is more dense than the New York Urbanized Area. But the suburbs of Los Angeles are far more dense than New York's.
9. Found at
http://www.census.gov/population/www/estimates/metroareas.html on 7 August 2000.
10. David Rusk. 1999. Letter to Ms. Georgia Masters, Department of Community Economic Development, State of Pennsylvania, Harrisburg. July 12. Rusk is an independent consultant on urban and suburban policy, the author of
Cities without Suburbs
, and the former mayor of Albuquerque, New Mexico.
11. See note 9.

[MFS note: works of several of the cited authors are available on the "Sustainability Authors" page here.]
_____
Used with permission of the authors.
Originally presented at the CAPS 2000 Conference: Waking from the dream: population and the Environment at the Millennial Edge.
University of Southern California, August 13, 2000.
See original at < http://www.sprawlcity.org/studyCA/index.html >.
Copyright c2000 by NumbersUSA.com.

 

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