What is an Indicator?
In the widest sense, an indicator is a sign or a signal that can convey a message, The message conveyed may be simple or it may be complex. Indicators provide us with information on things, situations, activities, processes or phenomena that exist or that are occurring in our surroundings. According to McQueen and Noack, indicators are defined as “. . .measures that summarize information relevant to a particular situation, or a reasonable proxy for such a measure”.
Examples of indicators include:
- A directional signal of an automobile: It can indicate when and how an automobile will turn.
- The temperature reading on a thermometer:
- It can indicate indoor or outdoor comfort levels;
- It can indicate the likelihood of disease-related conditions.
Indicators can have their greatest value as proxies or substitutes for measuring conditions that are so complex that currently there are limited possibilities for direct measurement. For example, data from reconnaissance orbiter photographs—and such other indirect measurements as exploration rover-based spectrographs taken recently—of the surface of Mars indicate the likely past presence of water.
Also, indicators may be aggregated or grouped (with or without weighting) into what are referred to as either indices or indexes. Often, these indices or indexes are useful in conveying complicated information in a simple, straightforward manner. A good example of an index is The American Consumer Satisfaction Index: a conglomeration—or aggregation—of econometric data collected through interviews. It is used to indicate how comfortable consumers say they feel about their economic condition—and that of the U.S. economy.
Indicators are developed and used predominantly to highlight the workings or the performance—or the lack thereof—of a system. The system may be biological, physical, chemical, economic or social. These indicators can tell us something about a system's status—and over time, about a system's operating trends. Indicators are used worldwide by scientists, governments, private-sector entities, and organizations and individuals in the general public. Their use of indicators boils down to having a “need-to-know”.
Again, indicators are as varied as the types of systems they monitor. However, according to the Website of Sustainable Measures, a provider of sustainability training services, there are certain characteristics that useful, effective, defensible and believable indicators have in common:
- Effective indicators are relevant; they show you something about the system that you need to know.
- Effective indicators are easy to understand, even by people who are not experts.
- Effective indicators are reliable; you can trust the information that the indicator is providing.
- Effective indicators are based on accessible data; the information is available or can be gathered while there is still time to act.
Why Use Indicators?
When properly developed, validated, and applied, indicators can assess trends, compare places and situations, provide simplified data, monitor progress, identify performance issues, and provide early warning information or signal emerging issues. In addition, indicators can help decision-makers and experts as well as involved, lay stakeholders identify information gaps and research priorities, and inform and influence policy development and program planning. This help can extend to the adjustment of strategies and resource allocation to improve the effectiveness of programs. Finally, indicators are typically applied for the purpose of telling a story, in particular to the public. Here they can provide a picture of trends and changes, assisting with information, education and awareness efforts. Overall, indicators are developed and used to clarify the operation of processes or to measure the impacts and outcomes of actions taken.
Environmental indicators are developed, validated and used to track changes to the quality and condition of the air, water, land, and ecological systems—and their resident biota—on various geographic and temporal (that is, time) scales. Other types of indicators focus on human health, social and economic conditions. For example, biological markers—also called biomarkers—are valued in disclosing, understanding, preventing and managing diseases in humans, domesticated organisms and in wildlife. Ideally, environmental indicators present scientifically-based, scientifically-defensible, and credible information on the status of, and trends in, environmental- and health-related conditions or situations.
Examples of environmental indicators include:
- The concentration of ozone in the stratosphere. It can indicate the effect of chlorofluorocarbons and the likelihood of increased levels of ultraviolet radiation.
- The number and diversity of organisms in a stream. These can indicate whether an aquatic ecological system is functioning normally.
Who Uses Environmental Indicators?
Over the last decade, a wealth of environmental indicators have appeared in the monitoring and reporting activities of such international organizations as the Organisation for Economic Co-operation and Development, the World Health Organization, the World Bank and the United Nations Environment Programme. In addition, they are being used by multi-national agencies such as the North American Commission for Environmental Cooperation (CEC) and the European Environment Agency - both of which maintain comprehensive indicator programs. Indicators have also found use at national as well as municipal levels (Environment Canada, the U.S. Environmental Protection Agency, the Mississippi 2020 Network, Inc.) and in the private sector (The World Economic Forum, The Business Roundtable). You can refer to other examples provided in the Further Reading section, below.
Three Key Groups of Environmental Indicators
There is no universal set of environmental indicators. Although many indicators appear to be the same, most indicators are developed narrowly by an agency or organization for specific, mission-oriented needs. For the purpose of better understanding how indicators are developed and used, indicator experts commonly group environmental indicators into the three categories discussed below.
State of the Environment Indicators
Descriptive "State of the Environment Indicators" focus on gathering information, based on existing, available information. They are used typically for "State of the Environment" reporting by government or think-tank agencies. Their focus is on providing a picture of what is happening to the environment, charting trends and changes in degradation or in environmental improvements. Descriptive indicators reflect the situation as it is, without reference to what it should or could be. Most sets of descriptive-style indicators in use are based on the so-called Drivers-Pressures-State-Impact-Response (DPSIR) model.
Examples of State of the Environment indicators include:
- Greenhouse-gas emissions (driving force indicator)
- CO2 emissions in key sectors (residential, business, transportation) (pressure indicator)
- Global temperature (state/impact indicator)
- Greenhouse-gas emissions and removals (response indicator)
These examples are from the European Environment Agency indicator set.
Another large group of indicators has been developed in order to measure sustainability or sustainable development. These kind of indicators have gained momentum since the 1992 Rio Earth Summit. Since then, a number of countries have adopted sustainable development goals on which they report their progress. Canada, New Zealand, Norway, and the United Kingdom are examples of countries that are fairly advanced in sustainability reporting. The work undertaken by international organizations such as the Organization for Economic Development (OECD) and the United Nations Commission on Sustainable Development (UNCSD) has and continues to play a strong catalytic and intellectual role in the development of sustainability indicators.
Sustainability indicators typically focus on a range of issues and are, ideally, broad enough to permit a complete appraisal of systems spanning both natural and managed ecosystems. These indicators can measure more than one aspect of the parameter and will commonly focus on both time, threshold (e.g.; efficiency, sufficiency, equity, and quality of life). Examples include:
- CO2 emissions per capita
- Percentage of forest renewal for harvested forest areas
- Renewable energy consumed versus total energy consumed
- Recovery of residential materials per capita
Environmental Performance Indicators
Performance indicators are commonly used by businesses, governments and non-governmental organizations to monitor, track and present to interested parties and the public overall progress on stated goals and benchmarks. Performance indicators monitor whether goals and targets will be met or not, and can communicate the need for additional measures. Unlike descriptive indicators, performance indicators focuses on the distance from a target, comparing actual conditions with a specific set of reference conditions. Ideally, performance indicators will report on results (e.g., a declining trend in emissions of nitrous oxide to the atmosphere), not efforts (e.g., number of fines laid on companies out of compliance).
- Business Roundtable. Environment, Technology and the Economy.
- Chesapeake Bay Program. Bay Trends and Indicators.
- Commission on Environmental Cooperation. 2002. The North American Mosaic: A State of the Environment Report.
- Environment Canada. Sustainable Communities Indicators Program.
- European Commission. Urban Audit: Assessing the Quality of Life of Europe's Cities.
- European Environment Agency.
- European Environment Agency. 1999. Environmental indicators: typology and overview.
- European Environment Agency. European Environment Agency Core Set of Indicators.
- European Environment Agency. Indicators about Europe's environment.
- Florida State University, Program for Environmental Policy and Planning Systems. General Environmental Indicator Links.
- Hart, Maureen. 1998. Characteristics of Effective Indicators. Sustainable Measures.
- Hart, Maureen. 1998. Environmental Data Indicators. Sustainable Measures.
- International Institute for Sustainable Development. A Global Directory to Indicator Initiatives.
- ^McQueen, D.V. and Noack, H. 1988. Health promotion indicators: current status, issues and problems. Health Promotion 3(1):117-125.
- Millennium Ecosystem Assessment.
- Mississippi 2020 Network, Inc. 20/20 Vision for a Sustainable Future.
- North American Commission for Environmental Cooperation (CEC).
- Organisation for Economic Co-operation and Development.
- Segnestam, Lisa. 2002. Indicators of Environment and Sustainable Development: Theories and Practical Experience. World Bank Environment Department.
- Stahl, Michael M. 2002. Performance Indicators for Environmental Enforcement and Compliance Programs: Basic Concepts and Best Practices. International Network for Environmental Compliance and Enforcement.
- The American Consumer Satisfaction Index.
- The Heinz Center. The State of the Nation’s Ecosystems.
- United Nations Environment Programme. Global Environment Outlook.
- U.S. Environmental Protection Agency. Environmental Indicators.
- U.S. Environmental Protection Agency. EPA Report on the Environment.
- U.S. Environmental Protection Agency. EPA Report on the Environment Publications.
- U.S. Environmental Protection Agency. Index of Biotic Integrity.
- World Bank. Environment Data and Statistics.
- World Bank. Environmental Economics and Indicators.
- World Economic Forum. Can Markets Save the Planet?
- World Health Organisation. Public health and environment.