Rate This Topic

Average: 0/5

Environmental Indicators

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[1], 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.

  • Geophony, Biophony, and Anthrophony Featured Article Geophony, Biophony, and Anthrophony Geophony, Biophony, and Anthrophony

    What do these words mean? Biophony is the melodic sound created by such organisms as frogs and birds; geophony, the composition of non-biological sounds like wind, rain and... More »

  • Sonoran Bumblebee Featured Article Sonoran Bumblebee Sonoran Bumblebee

    Bombus sonorus, the Sonoran Bumblebee The Sonoran bumblebee, Bombus sonorus, is a large and colorful native bee of the Sonoran desert and much of the western United States.... More »

  • Perdita minima Featured Article Perdita minima Perdita minima

    Perdita minima "World’s Smallest Bee" Native bees come in all shapes and sizes. Many gardeners are familiar with the large black and yellow... More »

  • Extremophile Featured Article Extremophile Extremophile

    An extremophile is an organism adapted to unusual limits of one or more abiotic factors in the environment. Some of the extreme conditions are temperature, pH, high salinity,... More »

  • Lionfish Spread Unprecedented Featured News Article Lionfish Spread Unprecedented Lionfish Spread Unprecedented

    Invasive Marine Fish May Stress Reefs The rapid spread of lionfishes along the U.S. eastern seaboard, Gulf of Mexico, and Caribbean is the first documented case of a... More »

  • Joshua Trees and Climate Change Featured News Article Joshua Trees and Climate Change Joshua Trees and Climate Change

    Uncertain Future for Joshua Trees Projected with Climate Change Temperature increases resulting from climate change in the Southwest will likely eliminate Joshua trees from 90... More »

Recently Updated
Improving access to and use of earth science data Last Updated on 2013-10-22 23:34:26 USGS Helps Debut New Technology to Improve Access and Use of Earth Science Data Researchers investigating global issues now have an easy method for finding and using earth science data through a new technology developed by the Data Observation Network for Earth, or DataONE.   Understanding broad and complex environmental issues, for example climate change, increasingly relies on the discovery and analysis of massive datasets. But the amount of collected data—from historical field notes to real-time satellite data—means that researchers are now faced with an onslaught of options to locate and integrate information relevant to the issue at hand.  DataONE, a ten-institution team with several hundred Investigators, including researchers from the United States Geological Survey (USGS), is addressing this data dilemma with a number of cyberinfrastructure and... More »
Indicators of sustainable development Last Updated on 2013-10-22 00:10:20 Indicators attempt to convey a broader image than the underlying statistics would suggest. For instance, the average life expectancy of an infant is usually taken to indicate the public health of a population. The purpose of selecting one or more indicators for describing a broader subject is to reduce information overload for data users. The strength and weakness of indicators lie in their selection, which facilitates decision-making but also opens the door to data manipulation. The alternative is aggregation of statistics and indicators into compound indices. Aggregation methods include the calculation of weighted or unweighted averages, summation in accounts and balances and mathematical reduction of correlated indicators by factor analysis. Indicator lists of varying length seek to capture the different – economic, environmental, social and institutional –... More »
Changes in the Landscape of Arctic Traditional Food Last Updated on 2013-10-21 23:45:06 This article, written by Tim Lougheed*, appeared first in Environmental Health Perspectives—the peer-reviewed, open access journal of the National Institute of Environmental Health Sciences. The article is a verbatim version of the original and is not available for edits or additions by Encyclopedia of Earth editors or authors. Companion articles on the same topic that are editable may exist within the Encyclopedia of Earth.   The Changing Landscape of Arctic Traditional Food The earliest European explorers seeking a northwest passage to Asia did not know what to make of the indigenous inhabitants they encountered in what is now Canada. In the 1500s, Martin Frobisher thought they were Asians and took a number as slaves; none survived more than a few weeks in captivity. Later adventurers acquired a profound respect for the knowledge that had enabled Inuit (“the... More »
Which fish should I eat? Last Updated on 2013-09-03 12:09:16 Despite the relative lack of information integrating the health, ecological, and economic impacts of different fish dietary choices, clear and simple guidance is needed to effect wise consumption of wild and domesticated fisheries resources. This Review article, written by Emily Oken, Anna L. Choi, Margaret R. Karagas, Koenraad Mariën, Christoph M. Rheinberger, Rita Schoeny, Elsie Sunderland, and Susan Korrick* appeared first in Environmental Health Perspectives—the peer-reviewed, open access journal of the National Institute of Environmental Health Sciences. The article is a verbatim version of the original and is not available for edits or additions by Encyclopedia of Earth editors or authors. Companion articles on the same topic that are editable may exist within the Encyclopedia of Earth. Which Fish Should I Eat? Perspectives Influencing Fish Consumption... More »
Global human appropriation of net primary production (HANPP) Last Updated on 2013-09-03 12:01:37 Humanity’s impact on the biosphere’s structures (e.g., land cover) and functioning (e.g., biogeochemical cycles) is considerable. It exceeds natural variability in many cases. Sanderson and others have classified up to 83% of the global terrestrial biosphere as being under direct human influence, based on geographic proxies such as human population density, settlements, roads, agriculture and the like; another study, by Hannah et al., estimates that about 36% of the Earth’s bioproductive surface is “entirely dominated by man”. HANPP, the “human appropriation of net primary production,” is an aggregated indicator that reflects both the amount of area used by humans and the intensity of land use. NPP is the net amount of biomass produced each year by plants; it is a major indicator for trophic energy flows in ecosystems. HANPP measures to... More »