The quest for an index of environmental sustainability - a composite measure that can summarize environmental performance along multiple axes and that can aid decision makers in choosing the best policies for both the environment and the economy - has intensified in recent years. Several efforts have been directed to develop comprehensive lists of indicators monitoring national or sub-national environmental performance. Although these have been notable for their broad consultative processes and for identifying critical indicators utilizing the best available scientific understanding, none to date has produced quantitative measures of environmental sustainability that permit comparative analysis of the levels and determinants of sustainability among countries.

Recognizing an opportunity to contribute in this area, last year CIESIN participated in an effort of the World Economic Forum, along with the Yale Center for Environmental Law and Policy, to develop a working prototype of an Environmental Sustainability Index (ESI). This brief overview describes the steps we took to develop the pilot Index, and identifies the next steps for refining the methodology and improving the data sets upon which the ESI is based.

The ESI is based loosely on the pressure-state-response framework, but with some important distinguishing features. The five discrete components that make up the ESI - environmental systems, environmental stresses, human vulnerability to environmental impacts, social & institutional capacity, and global stewardship - were derived from careful study of the elements that comprise environmental sustainability and a review of recent scholarship. The emphasis on elements of capacity, vulnerability and global stewardship, which are commonly missing in collections of environmental indicators, reflects our conclusion that these factors are integral to the concept of environmental sustainability. The five components, in turn, are composed of between two to six factors each, grouping together measures such as air quality, water quality, biodiversity loss, land degradation, waste production, disasters exposure, technical capacity, environmental regulation, eco-efficiency, and contributions to international environmental cooperation. A total of 65 variables are distributed among 21 factors. To calculate the pilot Index, countries were scored on a 0 (low sustainability) to 100 (high sustainability) scale based on where they fell in the range for any particular variable. These variable scores were then averaged to produce factor scores, and the factor scores in turn were averaged to produce the ESI.

An important constraint in the development of the pilot ESI was the availability of comprehensive and reliable global data sets. Many important variables could not be included in the calculations because the data are simply nonexistent or of questionable quality. Other indicators presented problems because their country coverage is highly limited. The fact that so few global data sets exist for so many of the world's most pressing environmental issues is a shocking indictment of our current system. We think that it constitutes one of the major impediments both to solid understanding of environmental conditions and to more effective policymaking. We are trying to work around this shortcoming in our current work. For example, we plan to draw upon regional or national data sets for variables with insufficient coverage, and to circumvent the data availability impasse through the utilization of data derived from global modeling exercises.

For the pilot phase we relied heavily on commonly used global data sets. This had many advantages, insofar as the data were readily accessible and in tabular formats with good country coverage. However, there were drawbacks as well. As we delve more into each data set and talk with the original compilers of the data, we have come to a better appreciation of each data set's strengths and limitations. We have concluded from this that we should seek to use original sources wherever possible.

Methodologically, we plan to use improved statistical techniques (e.g., principal components and factor analysis) and to identify if there are scientifically defensible thresholds and weighting schemes that should be applied to the indicators we use. We are also developing an interactive version of the index that will allow users to apply different weightings to variables and factors based on their own priorities and values.

Despite the data limitations, we have received positive responses to the pilot ESI from scholars, government officials, and environmental activists. Still, it is clear that more can be done. It is our hope that the ESI will spur national statistical agencies to take more seriously the collection, analysis and dissemination of environmental data. Otherwise, the world's policy makers will be navigating with incomplete, and possibly inaccurate, road maps. (For more details go to: http://www.ciesin.columbia.edu/indicators/ESI/pilot_esi.html.)

WHAT?

".the environment must become better integrated into mainstream economic policy. The surest way to achieve that goal is to modify systems of national accounts so that they begin to reflect true environmental costs and benefits - to move towards "green" accounting. .The System of Integrated Environmental and Economic Accounting, pioneered by the United Nations in 1993, is a response to this challenge. .Although this system of green accounting is still a work in progress, it is already employed by national governments. .I encourage governments to consider this system of green accounting carefully and identify ways to incorporate it into their own national accounts."

Thirty-first Session of the Statistical Commission (New York, 29 February-3 March 2000). The Statistical Commission approved the proposed consultation process and schedule of activities for the revision of the System of Integrated Environmental and Economic Accounting and recommended that the handbook on integrated environmental and economic accounting be submitted to the Statistical Commission for its approval at its thirty-second session in 2001.

UNSD/CARICOM project. The United Nations Statistics Division (UNSD) is organizing a Workshop on Environment Statistics for CARICOM Member Countries co-hosted by the Central Statistical Office of Belize. The Workshop will be held in San Ignacio, Belize from 2 to 11 August 2000. The Workshop is part of the project "Strengthening Capacity in the Compilation of Statistics and Indicators for Conference Follow-up in the CARICOM Region" whose Implementation Plan was endorsed by the Standing Committee of Caribbean Statisticians (SCCS) at its meeting in Georgetown, Guyana 10-13 January 2000.

The main objective of the Workshop is to familiarize participants with concepts and methods of environmental statistics and indicators and to promote a regional environment statistics programme. It will also provide a forum for exchange of information on the status of environment statistics at the national level. The outline of a regional publication on environment statistics will also be developed during the Workshop.

One of the outputs of the Project will be the publication of an analytical report on environment statistics based on data supplied by countries. The participants in the Workshop will form a network of experts that will collaborate with UNSD and CARICOM in the compilation of statistics and indicators relevant to the region.

News from the regional commissions

Sub-regional Training Workshops on Environment Statistics for countries in Asia and the Pacific (by Selma Guven and Andrew Flatt, Statistics Division, ESCAP).The Statistics Division of ESCAP, with the support of the Government of the Netherlands, is running a project that focuses on organizing a series of sub-regional training workshops on environment statistics in the region. The broad aim of the project is to improve national capabilities of the region's developing countries for identifying, collecting, processing, analysing and disseminating the data needed for formulating policies and programmes for environment and sustainable development, as well as for monitoring and evaluating the progress made.

The workshops are targeted at senior/middle level officials who are or will be directly involved in environment statistics or a closely related field, both from the national statistical agency and from the nodal department/agency dealing with environmental concerns. Participants are exposed to recent developments and methodological issues in the fields of environment statistics, indicators and accounting including definitions, classifications, survey and estimation methodologies, and data sources. They review the progress made in the countries/areas of the region in the field of environment statistics and share their experiences of issues encountered and strategies adopted to overcome some of the obstacles faced. The programme consists of four thematic modules, starting with a general introduction to the basics of environment statistics and its relation to indicators and accounting. The second module focuses on environmental pollution and environmental quality including air, water, and waste. The third module covers issues of ; land use, biodiversity and soil degradation as well as the use of remote sensing and geographical information systems, while the last module gives a brief overview of approaches to environmental accounting.

The first workshop was held in Bangkok from 8 to 19 May 2000. The thirty-one participants came from fifteen countries and areas in East and South East Asia. Under the current project, three more sub-regional workshops on environment statistics are being planned, for South Asian countries in late 2000, for Central Asian countries and Pacific Islands developing countries in 2001. (Additional information is available on the website of the Statistics Division: http://www.unescap.org/stat.)

WHO?

Ms. Alessandra Alfieri has been on sabbatical leave since February. During this period she has been completing her thesis for a Ph.D while continuing to work on the SEEA revision process.

Ms. Ilaria DiMatteo joined the Environment Statistics Section in May as an associate statistician to work on environmental accounting. She attended the University of Rome "La Sapienza" where she obtained a Doctorate in Statistical Methodology. She spent the last 5 years at Carnegie Mellon University, Pittsburgh, Pennsylvania working towards her PhD. Degree which she expects to complete this year.

Ms. Tanja Srebotnjak joined the Environment Statistics Section as associate statistician in April to work on environmental statistics and indicators. She studied Statistics and Theoretical Medicine at Dortmund University (Germany) and The University of Auckland (New Zealand) from which she graduated with a Diploma and Master of Science in 2000. In her studies she focused on epidemiological models for analyzing survival time data. She is particularly interested in environmental performance indices and exploring the effects of environmental degradation on human health and quality of life.

Within the framework of the United Nations Internship Programme, Mr. Ayaz Asif from the Blaise Pascal University, France, assisted UNSD from January to March 2000 with processing of data received from the UNSD Questionnaire on Environmental Indicators and doing library research. Ms. Ines Hambach from the University of Karlsruhe, Germany, assisted UNSD from June to August 2000 in its work on environmental statistics and indicators, in particular in the preparation of technical background material for the UNSD/CARICOM project.

About the authors

Mr. Andrew Flatt has worked for the United Nations in the field of statistics for many years. He is currently the Director of the ESCAP Statistics Division.

Ms. Selma Guven has been working as Statistician for environment and poverty statistics in the Statistics Division of the Economic and Social Commission for Asia and the Pacific of the United Nations (ESCAP) since October, 1999. Before joining ESCAP, she was the Head of Environment Statistics Division in the State Institute of Statistics in Turkey.

Alex de Sherbinin recently joined CIESIN as a Research Associate. He has held previous positions at IUCN-The World Conservation Union and the Population Reference Bureau.

Mr. Marc Levy is Director of CIESIN's Science Applications Division. He has taught at the Woodrow Wilson School of International Affairs at Princeton University and at Williams College, and has written widely on international environmental affairs.

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