This appendix provides additional information about the extensive work nationally and internationally to develop sustainability indicators.
Reviewing recent international work on sustainability indicators, it is evident that measuring sustainable development has been a subject of many studies ever since the publication of the World Commission on Environment and Development’s Our Common Future (WCED 1987). A comprehensive assessment of sustainability indicators was recently undertaken by the Scientific Committee on Problems of the Environment (SCOPE) (Hak et al. 2007). This assessment was followed by a collaborative effort on the part of statisticians in the United Nations Economic Commission for Europe (UNECE), Eurostat, and the Organisation for Economic Co-operation and Development (OECD) published as Measuring Sustainable Development (UNECE 2009). The approach taken in this report is a so-called capital-based one that examines ways to measure stocks and flows of economic (market-based), natural, human, and social capital. This approach is thoroughly discussed, drawing heavily on the Handbook for compiling the United Nations System for Environmental and Economic Accounts (UN/EC/IMF/ OECD/World Bank 2003), commonly referred to as the SEEA where sustainable development is defined as “development that ensures non-declining per capita national wealth by replacing or conserving the sources of that wealth” (p.4); that is, stocks of produced, human, social, and natural capital.
Although this approach implies substitutability among the different types of capital, the authors drew on the literature of strong and weak sustainability
to argue that some categories of natural capital should be defined as critical and thus not be allowed to fall below a minimum level: (1) a reasonably stable and predictable climate; (2) air that is safe to breath; (3) high-quality water in sufficient quantities; and (4) intact natural landscapes suitable for supporting a diversity of plant and animal life (UN/EC/IMF/OECD/World Bank 2003). Taking into account the difficulty of developing monetary measures for all the concepts needed, the authors argue for the use of physical measures and other proxies in developing a practical indicator set.
The authors noted that in actual practice, most sustainable-development indicator sets were policy-based—that is, capable of changing over a sufficiently short period of time to attribute the changes at least in part to specific policy measures. Examples of these types of indicators are emissions of greenhouse gases on an annual basis, energy use per unit of gross domestic product (GDP), mortality due to selected key illnesses. They identify 27 indicators used in indicator sets by at least 10 countries (see Table E-1). The authors do not question the usefulness of the policy-based approach, but strongly advocate that it be complemented by outcome-based indicators using the capital stocks- and flow-approach (UN/EC/IMF/OECD/World Bank 2003). Examples of these types of indicators are (1) (stock) average annual concentrations of ground level ozone, (flow) smog-forming pollutant emissions per month; (2) (stock) health-adjusted life expectancy, (flow) annual changes in age-specific mortality and morbidity, (3) (stock) real per capita natural capital, (flow) real per capita net depletion of natural capital. For more examples, see Table E-2.
The authors also reported a comparison of national and international sustainable-development strategies where they found that 11 indicator themes were common to a large number of the strategies: management of natural resources, climate change and energy, sustainable consumption and production, public health, social inclusion, education, socioeconomic development, transportation, good governance, global dimension of sustainable development, research and development, and innovation (UN/EC/IMF/OECD/World Bank 2003). The authors of the report suggested that most of the strategies can be captured by the outcome-based indicators they propose but that indicators related to efficiency and equity might well be added to the set to capture other dimensions of policy.
While the work mentioned above was under way, the United Nations Commission for Sustainable Development (UNCSD) revised its set of indicators in Indicators of Sustainable Development: Guidelines and Methodologies (UNCSD 2007). Because many of the same statisticians contributed to both exercises, there is considerable overlap, at least among the policy-based indicators. The UNCSD set now contains 50 core indicators among a larger set of 96 sustainable-development indicators. Among the 27 indicators mentioned above, all but one (unemployment rate) are included in the broader UNCSD set, and 20 of them are included among the core set.
TABLE E-1 Policy-Based Sustainable Development Indicators.a
|Rank||Broad Indicator||Number of Indicator Sets Where Used|
|1||Greenhouse gas emissions||22|
|3||GDP per capita||18|
|4||Collection and disposal of waste||18|
|6||Official Development Assistance||17|
|8||Life expectancy (or healthy life years)||15|
|9||Share of energy from renewable sources||15|
|10||Risk of poverty||14|
|12||Energy use and intensity||14|
|14||General government net debt||13|
|15||Research and Development expenditure||13|
|17||Area of protected land||13|
|18||Mortality due to selected key illnesses||12|
|21||Emission of ozone precursors||11|
|22||Fishing stock within safe biologic limits||11|
|23||Use of fertilizers and pesticides||10|
|24||Freight transport by mode||10|
|25||Passenger transport by mode||10|
|26||Intensity of water use||10|
|27||Forest area and its utilization||10|
a Based on indicators where 10 or more countries or institutions have adopted them.
SOURCE: Measuring Sustainable Development, by UNECE, copyright (2009) United Nations. Reprinted with permission of the United Nations.
A large number of the capital stock, capital flow, and policy indicators discussed in these two recent reports can be found in OECD collections of data and indicators. In the various reviews and monitoring mechanisms for which such indicators are relevant, the policy-oriented and output-oriented capital-flow types of indicators are well represented. However, the capital-stock indicators are not widely used in OECD work; nor are they often used in the national sustainable-development indicators of the OECD member countries.
A large number of sustainability indicators have been identified, a large fraction of which being most directly related to the environmental pillar. The large number of environmental indicators may be indicative of the complexities
TABLE E-2 Outcome-Oriented Sustainable-Development Indicators
|Indicator Domain||Stock Indicators||Flow Indicators|
Health-adjusted life expectancy
Percentage of population with post-secondary education
Temperature deviations from norms
Ground-level ozone and fine-particulate concentrations
Quality-adjusted water availability
Fragmentation of natural habitats
Changes in age-specific mortality and morbidity
Enrollment in post-secondary education
Greenhouse gas emissions
Nutrient loadings to water bodies
Conversion of natural habitats to other uses
Real per capita net foreign financial asset holdings
Real per capita produced capital
Real per capita human capital
Real per capita natural capital
Reserves of energy resources
Reserves of mineral resources
Timber resource stocks
Marine resource stocks
Real per capita investment in foreign financial assets
Real per capita net investment in produced capital
Real per capita net investment in human capital
Real per capita net depletion of natural capital
Depletion of energy resources
Depletion of mineral resources
Depletion of timber resources
Depletion of marine resources
SOURCE: Measuring Sustainable Development, by UNECE, copyright (2009) United Nations. Reprinted with permission of the United Nations.
involved in characterizing the environment, or social and economic indicators have had more time to mature. Therefore, such that a more refined set has been identified and is viewed as providing sufficient information. The large number of available indicators has resulted in a trend to reduce the large number by grouping indicators in indicator sets or to develop integrated or aggregated indicators, potentially all the way down to a single index of overall sustainability. An appropriately constructed indicator set should adequately characterize the state and potential trend of the environment at the scale applied. For example, OECD has reported on a set of aggregated indicators in Aggregated Environmental Indices: Review of Aggregation Methodologies in Use (OECD 2002).
Another effort to assess international sustainability indicators includes the Yale Environmental Performance Index. This index was developed to quantitatively assess a country’s national performance on a core set of 25 performance indicators tracked across ten policy categories, including environmental, public health, and ecosystem vitality. The index is used to gauge how closely countries meet environmental policy goals (Yale 2011).
DEVELOPING AND SELECTING THE APPROPRIATE SUSTAINABILITY INDICATORS
Although a large number of indicators may make communication more difficult and have less impact, information is potentially lost as the number of indicators is reduced, and the process likely to involve some level of arbitrariness, which can in turn lead to argument. For example, the Columbia/Yale Environmental Sustainability Index (ESI) began with 76 data sets grouped in five components to derive 21 indicators, which were then equally weighted to develop the ESI. The authors readily acknowledge the limitations of the ESI and understand that achieving full consensus on the appropriate weighting will be difficult. However, they also note its utility to gauge current environmental conditions and the likely future trajectory. Excessive narrowing of the range of indicators has the potential for negative unintended consequences, including masking potential trade-offs important to a decision.
Potential attractions to having a limited number of indices (potentially one) include communication and spurring change. The formulation of the index or indicator set, while open to debate, can also be used to promote beneficial change and to engage the public in the process. Public participation may include discussion of what indicator sets should be used. The index and indicator set would be integrative (synthetic), retaining the links between the facets of sustainability rather than being simply aggregate and would reflect all three pillars.
More detailed suites of indicators can be used for high-level analyses and discussions, such as identifying important trade-offs. For example the air-quality index (AQI) is a simple number that reflects multiple pollutant concentrations that is being effectively used to communicate something about the state of air locally. How to improve air effectively (and thus improve the local AQI) requires the consideration of a much larger set of indicators and the application of various tools to identify how the system will respond to policies and how indicators are linked. Thus, one set of indicators is linked to what is most directly actionable (emissions), another set is used to assess characteristics of the state of the system (pollutant concentrations) germane to the desired end point (healthy air), and the AQI is used to assist communication.
Data availability will be key to the development and use of sustainability indicators. Data availability could be accomplished by EPA collecting indicator data but not providing the score card. Local agencies should compile their own report cards based on guidance put forth by EPA. Data is the foundation of both indicators and the application and evaluation of tools. The type of data that should be collected will be determined as a product of goal setting and the resultant choice of indicators and tools. The potential availability of data will also inform the choice of goals, indicators, and tools.
Data that are likely to be used will probably be characterized by heterogeneity and range across multiple environmental measures. Collecting environmentally oriented data and maintaining them in a readily usable system, such as EPA’s
Regional Vulnerability Assessment (ReVA) Program,1 would introduce a systematic way to address the heterogeneity. Data that would be used for economic and social analyses would probably be obtained from the associated agencies.
Potential areas where environmental sustainability indicators may need to be introduced outside of typical environmental indicators are those characterizing health risks associated with environmental exposure and environmental justice. Further, fully capturing the benefits of adopting a sustainability approach will require adding indicators addressing economic and social considerations. Sustainability indicators currently do include health end points that may be impacted by environmental stressors. However, these indicators (e.g., hospital admissions, cancer incidence) usually describe endpoints that reflect many causes of which traditional environmental problems are a small fraction. These indicators may, in part, be drawn from World Health Organization (WHO) analyses (e.g., the Burden of Disease); prior EPA risk assessments; and work done by the U.S. Center for Disease Control (CDC). The advantages of such indicators are that they can be directly integrated within risk assessment and tools and expertise that already exist within and beyond the agency.
In the field of human health, there has been many advances in the modeling of infectious diseases using geographical information and similar advanced tracking tools, which can include the many indicators that are part of sustainability. The indicators are now being applied to environmental health by the integration of health, exposure, and hazard information (CDC 2010). Other social and economic parameters, such as housing stock and income, can be added, as is being done in the U.S. National Children’s Health Study of 100,000 children to be followed from early pregnancy to adulthood (Scheidt et al. 2009). However, the challenges to develop integrated indicators for environmental health are greater than for those infectious disease because the infectious disease cause and outcome are much more clearly linked (e.g., cholera is caused by Vibrio. Cholera, tuberculosis is cause by Mycobacterium Tuberculosis, and avian flu can be identified and tracked in birds and humans). For example, it is not known which cases of asthma are caused by ozone inhalation and which cases of bladder cancer are caused by arsenic in drinking water, thereby complicating the development of information needed to clearly link human health effects and the environmental risks managed by EPA.
1 The ReVA Program conducts research on various innovative approaches to evaluate and interpret large datasets and uses models to assess the current conditions and probable outcomes of environmental decisions. Working with various decision makers, such as regions or national program the data are used to understand the current conditions of an area of interest. ReVA is used to conduct research on stressors that may be influencing those conditions and to develop scenarios to project how stressors may look in the future (EPA 2009).
SUSTAINABILITY INDICATOR EFFORTS AT EPA
EPA, because of its mission, has focused more on the state of the environment than on economic and social considerations. In this respect, it has made considerable progress in recent years. In its 2008 Report on the Environment (ROE), the agency provided historical trends and analysis on 85 indicators related to the environment and human health (EPA 2008). The indicators chosen were based on a set of six well-defined criteria (see Box I-1 in the ROE) and were used in the five thematic chapters of the report: Air, Water, Land, Human Exposure and Health, and Ecological Conditions. Among the 85 indicators, both stock-and-flow indicators are represented, and many of them, particularly the flow indicators, are highly policy relevant. As might have been expected, they have been well chosen from an environmental and human health perspective. Some indicators were meant to be updated roughly every 2 years, and a number of them to were be updated each quarter. By the end of 2010, all 85 indicators had been updated. The report stated that administrative, socioeconomic, and efficiency indicators were not included. By and large, sustainable use of natural resources is not addressed either, with the exception of an indicator on freshwater utilization. Thus, the ROE cannot be used to understand the relationship between social or economic drivers and environmental pressures.
A sustainability approach would require EPA to use indicators that would include those additional considerations. Although identification of indicators involves other stakeholders, identifying economic and social indicators in particular can be done collaboratively with other agencies whose missions focus on those issues. Environmental justice is a growing concern, but review of the typical indicators used to characterize either social or environmental states suggest that there is a need to develop indicators specific to this concern.
Environmental sustainability indicators will be derived directly from observations or analysis of observations (e.g., as a result of modeling). Both types of indicators have uncertainties, and information about the level of uncertainty may be useful in Sustainability Assessment and Management approach and resulting decisions.
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