Measuring Urban Sustainability Hilda Blanco

University of Southern California

Outline

Introduction

Why Measure

Measuring Urban Sustainability

Methods and Tools for Urban Sustainability

Sustainable Cities Indicator Systems

Urban Scale Greenhouse Gas Inventories

Urban Metabolism Analysis

Conclusion

Introduction

Sustainability nebulous concept

Brundtland Commission Report Definition

Sustainable development is development that meets the needs of the present generation without compromising the ability of future generations to meet their own needs (1987)

Three aspects broadly recognized:

Ecological Economic Social

Why Measure?

• What you can’t measure, can’t improve.

Evaluation of implemented plans and policies is an essential aspect of planning process

Renewed calls for accountability and efficiency make evaluation of public actions more urgent

Measuring Urban Sustainability

Cities as Complex systems, no simple measures

Methods, Tools, Metrics interpret/ reduce complexity

Methods and Tools for Urban Sustainability Underlying methods: systems dynamics, multi-criteria

analysis

Three Urban-Scale Methods: sustainable cities indicator systems; urban metabolism; and, urban-scale greenhouse gas inventories

Data Availability

Sustainable Cities Indicator Systems Purpose/use

To track performance over time for a city and/or to compare cities’ performance along a set of indicators

What is an indicator?

A measure of the state of a system along a specific dimension

Vital signs of the health/sustainability of a system

A set of indicators are often aggregated into an index to rank or rate cities

What do they measure?

Policies or outcomes?

Systems that focus on municipal programs/policies

Kent Portney’s Taking Sustainable Cities Seriously (2003):

Smart Growth programs, land use/zoning, transportation programs and policies, pollution prevention, etc.

Ranking of cities based on number of programs, for example in the 2011 rankings, e.g., Portland, San Francisco and Seattle were tied for #1 with 35 programs, Wichita, Kansas was # 55 with 7 programs

Portney’s sustainable cities ranking can be found at: ourgreencities.com/

Systems that focus on outcomes

How Green is Your City?: The SustainLane US City Rankings Warren

Karlenzig and Paul Hawken (foreword)New Society Publishers (2007)

SustainLane Indicators

Many focused on actual performance:

Air quality ratings were based on EPA data on Air Quality Indexes along with EPA data on Air Quality Non-Attainment areas

Public Transit ratings were based on US Census/American Fact Finder data on transit ridership

For Planning and Land Use, the data analyzed included park percentage per total city land area (from the Trust for Public Land) as well as a sprawl ranking developed by Smart Growth America in a 2002 study of US cities

Siemens Green City Index

http://www.siemens.com/entry/cc/features/greencityindex_international/all/en/pdf/

report_northamerica_en.pdf

Siemens Green City Index

http://www.siemens.com/entry/cc/features/greencityindex_international/all/en/pdf/report_

northamerica_en.pdf

http://www.siemens.com/entry/cc/features/greencityindex_international/all/en/pdf/report_northa

merica_en.pdf

Siemens Green Cities Index, list of categories, weighting, etc. (Cont.)

http://www.siemens.com/entry/cc/features/greencityindex_international/all/en/pdf/repo

rt_northamerica_en.pdf

In the testing stage

• The STAR Community Index developed by ICLEI in partnership with US Green Buildings Council, Center for American Progress, and the National League of Cities

• A national, consensus-based rating system—product of a stakeholder process

• Sustainability planning and performance management tool

• E.g., in the goal area of Nature, validation measures would be to conduct natural systems inventories of existing conditions, and to establish conservation targets and natural systems plans

Criteria for Indicators

Available, up to date, and able to be reported annually;

Readily comparable among cities;

Relevant for public policy decision making and/or linked to established goals (e.g. MDG);

Cost effective to collect;

Meaningful to cities across a nation or globally regardless of geography, culture, affluence, size, or political structure;

Understandable and not overly complex;

Clear as to whether changes in the indicators are good or bad.

Source: Global City Indicators Facility, http://www.cityindicators.org/themes.aspx

Methodological issues

Are the indicators given different weights? On what basis? Is the rationale for weighting explicit?

Do they take into account inherent risks or endowments?

Data Availability

The quantity and type of data available

How often is it updated?

How reliable or trusted is the data?

How accessible is it? Is it public data?

Are the data sources referenced in the system?

Challenges • Not clear whther the results are outcomes of

specific sustainability policies/programs or a combination of different factors, including regional advantages or disadvantages?

• Most do not take into account regional or local advantages or disadvantages, such as plentiful or scarce water supplies or vulnerability to natural hazards, low vs. high income populations?

• Need for linking policies to performance

• Most important, lack of an integrated approach to urban systems

Urban-scale Greenhouse Gas Inventories

Purpose

Establish baseline, and periodic monitoring of energy use and green house gas emissions

Essential step in climate action plans focused on mitigating GHG emissions

The emissions formula (IPCC 2006)

GHG emissions (CO2eq) = Activity Data * Emission Factor * GWP

Many GHGs, typically reported as CO2 equivalents

Activity data refers to data on “the magnitude of human activities resulting in emissions or removals taking place during a given period of time”

Emission Factor refers to the “coefficient that quantifies the emissions or removals of a gas per unit activity”

Global Warming Potentials (GWP)

calculated as the ratio of the radiative forcing of one kilogramme greenhouse gas emitted to the atmosphere to that from one kilogramme CO2 over a period of time (e.g., 100 years), e.g., the GWP of CO2 is 1, the GWP of methane (CH4) is 21, the GWP of N2O is 310

ICLEI’s Protocol

ICLEI-Local Governments for Sustainability International NGO—with a focus on helping governments

implement Agenda 21

Over a 1,000 cities joined ICLEI’s Cities for Climate protection program

Prepare GHG inventory to establish baseline emissions

Develop a Climate Action Plan

ICLEI has initiated a Cities Climate Registry--global repository of GHG inventories in Bonn--“carbonn”

ICLEI’s GHG Inventory Protocol International Local Government GHG Emissions Analysis

Protocol (IEAP)

ICLEI’s IEAP (2009)

ICLEI’s dual inventories for localities

Government operations analysis which adopts an organizational boundary

Focusing on emissions from activities under the control and function of the local government, no matter where the emissions occur

Community analysis which adopts a geopolitical boundary

Focusing on emissions from activities within the jurisdictional boundary of the local government (ICLEI 2009)

This distinction raises the issue of scope

Scope

Direct vs. indirect emissions

ICLEI uses the concept of scope to address this issue: Scope one emissions

direct emission sources owned or operated by the local government or the direct emissions located within the geopolitical boundary (except CO2 emissions/removals from biomass combustion) ;

Scope two emissions indirect emissions related to electricity, heating and cooling

consumption;

Scope three emissions all the other indirect and embodied emissions (ICLEI, 2009)

Example: Carson Scope 1 Emissions

City of Carson, California. Municipal Greenhouse Gas Inventory Report. South Bay Cities

Council of Governments, Oct. 2009

http://www.southbaycities.org/files/City%20of%20Carson%20Municipal%20Inventory_1.pdf

Carson Scope 2 Emissions

City of Carson, California. Municipal Greenhouse Gas Inventory Report. South Bay Cities

Council of Governments, Oct. 2009

http://www.southbaycities.org/files/City%20of%20Carson%20Municipal%20Inventory_1.pdf

Carson Scope 3 Emissions

City of Carson, California. Municipal Greenhouse Gas Inventory Report. South Bay Cities

Council of Governments, Oct. 2009

http://www.southbaycities.org/files/City%20of%20Carson%20Municipal%20Inventory_1.pdf

Challenges

• Developing GHG emissions inventories involves gathering information from multiple agencies and data sources, which requires political support and coordination.

• Longitudinal data are important for GHG inventories, since their purpose is to provide a baseline for climate action plans. This will require consistent tracking of energy use.

• Scope 3 emissions can be measured, but the ability of localities to influence these emissions are more limited

• Inventories are focused on activities that generate GHG emissions and not other aspects of sustainable cities

Urban Metabolism Analysis

“The sum total of technical and socioeconomic processes that occur in cities, resulting in growth, production of energy and elimination of waste.” (Kennedy, Cuddahy and Yan, 2007)

Measurement of 4 main elements: energy, materials (including land), water, nutrients

Cities as complex systems Wolman (1965) introduced the concept of urban metabolism, conceiving cities as open systems metabolizing inputs of energy, water, raw materials, and discharging wastes into their environments.

He calculated that a hypothetical city of one million people needed 2,000 tons of food, 4,000 tons of fuel, and 630,000 tons of water as daily inputs. These are converted daily into 2,000 tons of garbage, 500,000 tons of wastewater with 120 tons of solid particles, and 950 tons of atmospheric pollutants.

Wolman, A. 1965. The metabolism of cities. Scientific American 213(3): 179–190.

Why important?

Understanding the whole picture Including the diversity and relative weights of primary

energy and materials inputs

Creating a common language for interdisciplinary groups Helps people understand infrastructure as whole systems,

focus on parts with high use, and opportunities

Developing and communicating alternative development scenarios

Setting priorities for research and design Each node represents opportunities for substitution,

efficiency, etc.

Calculating performance indicators in transparent and comparable ways Every flow is a potential indicator

The baseline for developing strategies to achieve a more ecologically sustainable city

Urban Metabolism Inputs

Resources directly from nature, e.g., rainwater, sunshine, biomass or imports from other regions

They are then tracked as they flow through the city’s infrastructures and buildings

Inputs are typically processed E.g., biomass burned, turning it into heat

Flows then used to satisfy demand for services E.g., drinking, lighting, cooking

After servicing demand, flows may be processed again E.g., sewage treated, biogas captured and recycled

Urban Metabolism Outputs

Flows returned to nature as waste and emissions to air, water, land

Or stored or exported to other regions

Urban Metabolism analysis uses a balanced budget model:

Inputs = Outputs

Source: Newcombe et al. (1978) Metabolism of a City: The case of Hong Kong.

Ambio, p. 4

The Urban Metabolism of Hong Kong (1978)

LA County 2000 Urban Metabolism Study

Ngo and Pataki (2008) The Energy and Mass Balance of Los Angeles County.

Urban Ecosystems

Urban Metabolism Schematic

Developing a pragmatic approach to assess urban metabolism in Europe. A Report to the

European Environment Agency(2010) J. Minx, F. Creutzig, V. Medinger et al. Stockholm

Environment Institute.

Developing a pragmatic approach to assess urban metabolism in Europe. A Report to the

European Environment Agency(2010) J. Minx, F. Creutzig, V. Medinger et al. Stockholm

Environment Institute.

Data needs

Developing a pragmatic approach to assess urban metabolism in Europe. A Report to the European Environment

Agency (2010) J. Minx, F. Creutzig, V. Medinger et al. Stockholm Environment Institute.

Conclusion

Measuring urban sustainability Sustainability Indicators: Static, discrete indicators of

programs or outcomes on broad range of issues

Greenhouse Gas Emissions Inventories: measuring GHG emissions from several sectors, mostly focused on energy use and related to climate change mitigation policies

Urban Metabolism Analysis: complex systems framework for understanding urban patterns and flows, and planning more sustainable cities

Different purposes, scopes, data needs

Urban Metabolism Approach—future potential for ecologically-based urbanism and planning

References Alberti, M. (1996). "Measuring urban sustainability." Environmental

Impact Assessment Review 16(4-6): 381-424.

City of Carson, California. Municipal Greenhouse Gas Inventory Report. South Bay Cities Council of Governments, Oct. 2009. http://www.southbaycities.org/files/City%20of%20Carson%20Municipal%20Inventory_1.pdf

Economist Intelligence Unit. 2011. US and Canada Green City Index. Siemens AG. http://www.siemens.com/entry/cc/features/greencityindex_international/all/en/pdf/report_northamerica_en.pdf

Global City Indicators Facility, http://www.cityindicators.org/themes.aspx

ICLEI, 2009. ―International Local Government GHG Emissions Analysis Protocol‖,

http://www.iclei.org/fileadmin/user_upload/documents/Global/Progams/GHG/LGGHGEmissionsProtocol.pdf

IPCC (2006). Guidelines for National Greenhouse Gas Inventories, Volumes 1 to 5, http://www.ipcc-nggip.iges.or.jp/public/2006gl/index.html

References (cont.)

Karlenzig, W. 2007. How Green is Your City?: The SustainLane US City Rankings. New Society Publishers. http://www.sustainlane.com/

Kennedy, C., J. Cuddihy and J. Engel-Yan (2007). "The Changing Metabolism of Cities." Journal of Industrial Ecology 11(2): 43-59.

Minx, J., F. Creutzig, V. Medinger et al. 2010. Developing a pragmatic approach to assess urban metabolism in Europe. A Report to the European Environment Agency. Stockholm Environment Institute.

Newcombe K. et al. (1978) Metabolism of a City: The case of Hong Kong. Ambio, 7: 3-15.

Ngo, N.S. and D.E. Pataki (2008) The Energy and Mass Balance of Los Angeles County. Urban Ecosystems 11: 121-139.

Portney, K. 2003. Taking Sustainable Cities Seriously. MIT Press

US and Canada. http://ourgreencities.com/

Wolman, A. 1965. The metabolism of cities. Scientific American 213(3): 179–190