Stephanie Pincetl, University of California, Los Angeles, Los Angeles, CA, USA

Presentation Title: Positioning urban metabolism to enable future transitions: An integrated infrastructure, economic and behavioral assessment of Los Angeles



Urban metabolism studies have been conducted for dozens of cities across the world. Most of them have been conducted using aggregated or simulated data, as data at finer spatial scales are often unavailable and rarely fully integrated with socio-demographic information, historical data, land-use and policy decisions. This limits the ability to determine drivers of current metabolisms and how hard and soft infrastructure combine to create path dependencies that make transitions difficult. Some preliminary results from a study of Los Angeles using integrated data rich methods are presented. This approach sheds light on drivers of current patterns and reveals path dependencies that need to be addressed to transition to a more sustainable metabolism.

Key Lessons Learned

Cities are the result of historical evolution and their current patterns are contingent on economic activity.  However, they are also the reflection of hard and soft infrastructures that co-produce the urban fabric.  This means that the physical infrastructure of pipes, wires, roads and buildings is both predicated on and shapes the soft infrastructures of codes, rules, conventions and laws.  These hard and soft infrastructures themselves are imbricated in culture, politics, economics, science and values.  Modernist cities of the 20th century have set expectations about how cities should be built and what services should be available, and these were developed in a period of abundance – abundance of fossil fuels, water, materials and money.  Their functioning is, in the best of circumstances, based on knowledge and rules.  For a post carbon city, the complex system that has created and upholds the modernist city, must be rethought and revised.

Policy/Practice Implications of Research

Bottom-up data is difficult to obtain, but critical, especially coupled with life-cycle analysis and political ecological analysis.  Not only does the bottom-up data empirically show who is using what and where to do what, but with an understanding of the supply chain, environmental impacts and impacts on places of origin, it helps to shape policy.  For example, cap and trade programs without leakage policies simply displace carbon production elsewhere.  Moving toward electrification of the transportation system means new impacts on places of origin for lithium, like the Bolivian Altiplano.  Without corporate responsibility mechanisms or ecological planning, those places are simply sacrifice zones.

One of the most difficult parts of the work is the connection between drivers of patterns (World Trade Organization agreements or General Agreement on Tariffs and Trade, tax policy, rules and codes) and resource use.  The second is policy change and the unpacking of the system toward de-growth in the affluent North (coupled with strong programs for more equitable distribution of wealth), and sufficient growth in the global South to achieve healthy and productive lives.  The challenge is to move away from an economic system that is dependent on growth in consumption.

Water mapping work has demonstrated beyond a doubt the link between affluence and water use, and more specifically, outdoor water use.  Without the bottom up data, there was a lot of confusion about this issue, confounding climate with simple over-use of water.  Adding the use of satellite imagery to discern density of greenness, it shows that even in times of water restrictions, landscapes remained green in Los Angeles, demonstrating that landscapes are over-watered, in addition to the use of inappropriate plants in the Mediterranean climate zone. In Southern California, water is pumped over the Tehachapi Mountains, making water conveyance the single largest energy user in the state.  The water/energy nexus is very strong.

Knowledge Gaps and Needs

There are many knowledge gaps and needs to change an economy predicated on growth and its reliance on fossil energy to do so.  Those who quantify carbon must look at bottom-up data to understand how carbon fuels move through the economy and are embedded in all aspects of urbanization, from moving water into cities to fueling sewage treatment plants, to transportation, manufacturing and more.  This understanding must be linked to policy drivers, whether sanitation codes, engineering specifications, or incentives that make using carbon-based fuels continue to be less expensive than alternatives.  There is a great deal of research that must be conducted on scale relative to alternative energy production and distribution, for example, what energy can be produced with distributed generation, and what can be supplied from more decentralized locations (e.g., solar vs. biogas).  These also need to be linked to urban morphology – how much space in cities is needed for this kind of energy generation?  How much space in cities should be devoted to stormwater capture and ground water recharge?  Can cities be reengineered, and what steps are involved to do so?  What are the lifecycle impacts of different construction types and transportation modes?  All of these have important material and energy implications that must be quantified and linked to politics, economics and justice concerns if we are to move toward lower carbon futures.


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