Global Land-Cover Change & Urbanization

Problem Narrative
"The pace, magnitude and spatial reach of human alterations of the Earth's land surface are unprecedented."1 Land-use and land-change impacts are significant, and seemingly every-growing. Biodiversity worldwide is diminishing, local and global climate change occurring, soil degradation increasing – and all are linked to land-change developments.

Many misconceptions are associated with land-change impact. Often they are simplifications of cause-effect relationships which fit neatly into current world views, or suggest simple solutions. Because of this, they propagate and gain popularity and over time influence environment and development policies.

Urbanization is a land-cover change which is often viewed as insignificant on the global scale because urbanized land occupies less than 2% of the earth’s land surface. However, the relationship between urban-rural connections is an important one. Urban lifestyles on average raise human consumption patterns and expectations. “In 1950 less than 30% of the world’s population lived in cities. This number grew to 47% in the year 2000 (2.8 billion people).”2 The United Nations Population fund estimates that by 2025, 60% of the world’s population will living on urbanized land.

On a global scale, policies that trend toward greater urbanization are rising. Increasingly more work is found in urban centers, leaving rural areas with unfavorable prospects. There exists a lack of planning and government intervention to structure and disperse economic opportunity between urban and rural centers. As well, in much of the world land-use management is decentralized, left in the hands of local governments ill adept in comprehension land-use strategies.

Study purpose
The purpose of this study is to seek a better understanding of the real drivers of land-use and land-cover change, particularly in urban environments. It aims to demonstrate the significance of urbanization on global land-change impacts and express how the role of misconceptions in land-cover change can exacerbate environmental issues related to land development.

Questions that the study will address:

• How and to what degree do economic opportunities drive land-cover change?
• What are the primary misconceptions of land-use / land-change scenarios that contribute to land-change patterns?
• To what degree does lifestyle expectation influence urban land-use patterns?
  

1 "The causes of land-use and land-cover change: moving beyond the myths" www.elsevier.com/locate/gloencha

2 http://doc-aea.aide-et-action.org/data/admin/global_urban_population.pdf

Suggested CLD to the Problem of Seals and Vessels

This CLD is in response to Abby's post, "Unintended Consequences of Boats and Kayaks on Harbor Seal Populations." I did not see a way to attach my diagram to the comment I left on Abby's page, so I'm posting here instead.

Enjoy. :)

Working with Causal Loop Diagrams

Working with Causal Loop Diagrams (CLD) is interesting and maybe even fun... But preparing a Causal Loop Diagram (CLD) from scratch is actually quite difficult. Getting started on the right path was not easy. But finally, after a few rough drafts and scrapped CLDs, and I had my diagram.

The situation I chose to model is one focused on an aspect of social dynamics, namely the goal to be a desirable friend. Generally, an individual would aim to please others in effort to increase his social utility. As social utility increases, he becomes more popular and more of his time is demanded by others. This results in less available time, and as the individual has less time available, his desire to please and to be agreeable decreases.

The unintended consequences however create a scenario where an individual can end up as a loner instead of a person with a full social schedule. As an individual increases his desire to please those around him, he may actually end up increasing his indecisiveness and indifference because he is more concerned with seeming agreeable than actually forming an opinion or making a decision. As a result, frustration among friends increases, thereby decreasing his popularity, freeing up his social schedule (available time), which ultimately further increases his desire to please those around him.

The mental model is inadequate because it leaves out a number of other variables which influence social behavior and dynamics, such as the number of other people this person is trying to satisfy, the state of mental health of the individual, and opportunities for socializing. There may be a need for delays in this model, depending on circumstances. For example, it make take a long while for this person's indecisiveness to result in feelings of frustration among his friends.

I know this model can be better... even as I've been writing this blog, I've rethought several of my variable names and causal relationships. But, this is where you come in... what are your thoughts? How can this model be improved? What glaring issues have I missed? Click on the image for a closer look at the diagram.

The Nature of Urban Sprawl

Land-use planning and conservation is a topic that I am passionate about. Growing up in a rural town, year after year I watched forested land cleared for new subdivisions and once-functioning farmland run vacant, plotted with 'for sale' signs. (The American Farmland Trust estimates that 46 acres of farmland are lost every hour!) Yes, we have an ever-increasing population and those people need a place to live. But does population growth necessitate the patterns of land-use and consumption that we've seen in these recent decades?

The most significant growth and development changes in the United States are marked predominantly by the aftermath of World War II. From this point, development and growth has taken form as divided land and single-family subdivisions distanced from the places where people work, shop, and play. Additionally, rates of population growth are severely out of balance with land consumption. For example, in the Milwaukee metropolitan area between 1970 and 1990, the population grew at approximately three percent. Correspondingly, land consumption grew at a rate of thirty-eight percent. In Los Angeles over this same time period, population growth figured at forty-five percent while land use increased three-hundred percent. (Cieslewicz) But it is not just the excessive consumption of this land that is a problem – it’s the way in which the land is developed. Consumption of open space along side improperly planned development can create fragmented habitat, the decline of prime farmlands and a number of other environmental issues which include air pollution, water pollution, and loss of biodiversity.

This problem, in my opinion, has evolved over time based on three significant factors: 1. the 1926 United States Department of Commerce Standard State Zoning Enabling Act (SZEA), 2. Government Subsidies, and 3. the social perception of the American Dream. The SZEA delegated the responsibility of land-use planning and zoning to local governments. At the time of delegation it was accepted as true that mixing land uses would negatively impact the health and safety of local residents. As such, the idea of exclusive zoning and separation of land-use was birthed, creating the signature development patterns of today’s urban sprawl. (Attkisson) Government subsidies have shaped the direction of this growth by way of supplying Federal tax deductions for home mortgages and freeway building. Deductions on home mortgages encourage inexpensive homes on cheap land; subsidies on freeway building have promoted road building and dispersed development over wider areas. Finally, social acuity propels the issue of sprawl. Fastened to the societal threads of national culture, sprawl is linked to the very idea of the American dream – the idea that everyone has the right to achieve a better, richer and happier life which includes home ownership. As such, a common social mindset substantiates the right to claim resources and available open space.

The variables to track over time, in order to illustrate the problem of urban sprawl and its imbalance with population growth, include population growth, amount of fragmented land and percent of newly consumed/developed land. The system in which this problem exists includes a collection of hard and soft elements. Hard elements in this system, or those able to be measured or quantified, may include:

* Acres of Developed Land
* Number of Developers
* Zoning Policies Encouraging Divided Land Use
* Non-Contiguous Community Development
* New Roads
* Air Pollution
* Water Pollution
* Acres of Open Space

Soft elements, or those elements not easily measure or quantified, may include:

* Demand for Single Family Houses
* Acceptance of High Density Housing
* Support of Land-use and Zoning Policy Revisions
* Desire for Home Ownership

Urban sprawl is highly dynamic, interdependent and largely complex. Compounding the issue is that academics and developers alike do not agree on a single explanation of what defines sprawl. Perhaps with a systems modeling approach, the complexities and evolving environmental issues of sprawl will become more clear enabling stakeholders to clearly define it, and ultimately begin a path of solving the problem.



References:

Attkisson, Lesley R. "Putting a Stop to Sprawl: State Intervention as a Tool for Growth Management." Vanderbilt Law Review (2009): 980-1015.


Cieslewicz, David J. "The Environmental Impacts of Sprawl." Editorial Advisory Board, The Urban Institute Press. Urban Sprawl - Causes, Consequences & Policy Responses. Washington, DC: The Urban Institute Press, 2002. 23-38.

Impressions & Experience of SERM

I work hard and I want to make a positive impact with my life. My interest in the environment and sustainability comes from my appreciation of nature and intrigue in all the mysteries of life. I was attracted to SERM both for the content of the course and the experience of living abroad. I have found the experience so far to be fulfilling, despite some up and downs of a first year program. My interests more and more are in the realm of urban sustainability and land-use management. After completing my degree, I hope to put my knowledge to use in the city of Philadelphia, helping to transform it into America's greenest city.