The following historical perspective on the development of Earthwatch was prepared by Mr. C.C. Wallen who has been involved with Earthwatch in various capacities from its inception.

Origins 1972-1979
Review 1979-1981
Second Phase 1981-1989
System-wide Earthwatch Development 1990-1995

Origins 1972-1979

The concept of "Earthwatch" was launched in the Action Plan of the Stockholm Conference on the Human Environment in 1972 and defined as the coordinated function of the following activities considered to be required for carrying out of assessments of the global environment (1):
1. Evaluation and review of urgency of global issues (evaluation);
2. Collection of available data and information as well as organization of specific observations, as required to fill gaps (monitoring);
3. Research with existing and emerging data (research); and
4. Information exchange and dissemination of knowledge to decision makers.

Although the word "Earthwatch" and the concept have been used within the UN system since 1972 to cover the various activities involved in the global environment assessment function, the concept did not materialize as a title of any branch of UNEP. This was largely due to a political situation which became obvious as early as in the first Governing Council of UNEP in 1973 (2). The developed countries were in favour of the assessments of the global environmental pollution problems becoming a main issue for the new environmental programme and wanted for this purpose the "Earthwatch" concept to become a main function of UNEP. The developing countries, however, felt that global issues and in particular the pollution problems were of little interest to them, as these problems had been created basically by the developed countries and at that time were confined to the developed world. They pointed out that the assessments of degradation of soils, disappearance of natural resources, desertification and other regional problems were much more vital for them. Consequently it became delicate to define detailed terms for a Unit with the title: Earthwatch. Another reason for Earthwatch not materializing was the rather negative sceptical attitude of the specialized agencies which had difficulties in accepting UNEP taking a lead function in a system-wide Earthwatch as was hinted at in a circular letter on global monitoring from UNEP to the agencies dated around the end of 1973. Due to these various reactions the Executive Director of UNEP, in order to avoid political problems with the terms of reference, decided to call the Earthwatch function within UNEP "Environmental Assessment" which became the title of the assessment (sensing) branch of UNEP's programme.

The creation of GEMS

The most urgent problem for UNEP was to establish a special unit which would deal with the collection of available data and information and with filling gaps in environmental data availability by setting up new systems for specific observations. In this context the word "monitoring" started to be used for differentiating "observations established for specific purposes" from long-term scientific observations.

As early as August 1971 an expert meeting was convened in WMO by the organizers of the Stockholm Conference to consider the need for global environmental monitoring systems. The venue obviously was chosen because of the experience WMO had with setting up global networks like the World Weather Watch and the background air pollution monitoring network (BAPMoN).

ICSU/SCOPE was at the time preparing a booklet which presented most of the arguments for creating by international agreement a Central Monitoring Co-ordinating Unit which would coordinate the monitoring activities for the global environment. A draft of this booklet was available at the meeting and constituted the main background paper (3). The expert meeting recommended to the Stockholm Conference in 1972 that these activities should become a basic function of a relevant UN body for the environment (4).

The Stockholm Conference accepted in principle this recommendation, and in 1974 UNEP convened an Intergovernmental Meeting on Monitoring in Nairobi to consider the establishment of a Global Environment Monitoring System (GEMS) (5). This meeting more clearly demonstrated the political difficulties mentioned above which had become obvious at the first Governing Council of UNEP. The developing countries were sceptical of the global approach to GEMS favoured by developed countries but achieved the result that monitoring of natural resources was accepted as important as monitoring of environmental pollution. The specialized agencies, having been very active in the Interagency Group created for preparing the meeting, showed scepticism to a GEMS operated by UNEP and maintained that global monitoring operations could only be organized successfully by them according to their mandate. Nevertheless UNEP together with the governments argued successfully for the establishment of a world-wide system with the task to coordinate and catalyze global environmental monitoring activities which would be operated by UN specialized agencies, NGOs or countries. In other words GEMS was created. As the meeting concluded that it was not practical to separate monitoring activities from assessments the meeting passed over to GEMS responsibility for assessments within Earthwatch in the following goals for GEMS:

1. An expanded warning system of threats to human health;
2. Assessment of the extent and distribution of contaminants in biological systems, particularly food chains;
3. Assessment of global atmospheric pollution and its impact on climate;
4. Assessment of critical environmental problems arising from agriculture and land use practices;
5. Assessment of the response of terrestrial ecosystems to environmental stress;
6. Assessment of the state of ocean pollution and its impact on marine ecosystems;
7. An improved international system allowing monitoring of the factors necessary for understanding and forecasting of disasters and the implementation of an efficient warning system.

The Governing Council in the same year accepted the recommendations of the Monitoring meeting (6) and the GEMS's terms of reference.

The Executive Director of UNEP created a GEMS/PAC for coordinating some fundamental activities under "Earthwatch", i.e. those related to the subject areas of collection of available environmental data as well as filling the gaps in this availability. A Director of GEMS was appointed to be based in Nairobi to develop the PAC activities and a Deputy Director was appointed to be based in Geneva to be in charge of the direct relations with the specialized agencies and with special terms of reference to liaise with WMO where he was provided an office. A third professional was hired to work under the Director in Nairobi.

The mandate of GEMS and the Earthwatch concept

In a document prepared for the third session of the Governing Council in 1975, the Director of GEMS summarized the outcome of the Intergovernmental Monitoring Meeting in 1974 and the way he saw the initial approach to GEMS and its development. In this paper (6) GEMS was described as "a coordinated effort on the part of Member States, UN agencies and UNEP to ensure that data on environmental variables were collected in an orderly and adequate manner for the purpose of giving the Governing Council a quantitative picture of the State of the Environment". In more detail the implementation of GEMS was viewed as a process involving four phases (7):

1. Developing and testing monitoring methodologies, techniques and instrumentation; thereafter setting up and maintaining monitoring programmes and networks, carrying out calibration of data control, securing the participation of as many countries as possible;
2. Collecting, validating, storing and systematizing the monitoring data in permanent data centres and making them available;
3. Evaluating and interpreting the data for their use in environmental assessments; and
4. Using such data and assessments as inputs in policy formulation, decision making and management as well as for further research monitoring and evaluation.

The third session of the Governing Council of UNEP consequently adopted the guidelines presented by the Director of GEMS (7).

It is obvious that with its limited staff the GEMS/PAC could not cover all of its mandate. The Director decided to give priority to finding out and to try to fill the gaps in availability of data for global assessments through the following approaches:

1. Catalyzing and supporting new environmental monitoring activities with relevant agencies, ex. HEALs (Human Exposure Assessment Location);
2. Supporting external ongoing activities clearly within the UNEP mandate (BAPMoN, GEMS/AIR, GEMS/WATER).

Gradually this lead to GEMS/PAC activities being clustered in the following way:

1. Health-related monitoring;
2. Climate-related monitoring;
3. Natural resources and integrated monitoring;
4. Marine pollution monitoring; and
5. Monitoring of long range air transport of pollutants.

Towards the end of the 1970s it was agreed between the Director of GEMS/PAC and the Director of the Oceans and Coastal Areas Programme Activity Centre (OCA/PAC) that Ocean-related monitoring would be dealt with by OCA/PAC, although to keep abreast of ongoing activities, a GEMS staff member normally should attend meetings on monitoring of the oceans organized within the UN system.

In its wider sense, the "Earthwatch" concept was, after the start of GEMS/PAC in 1975, handled partly under "Environmental Assessment" and partly under GEMS/PAC. However, at this early stage comprehensive assessments could not be made because sufficiently good data for carrying out assessments of global environmental issues did not exist. Neither was there at this time any systematized collection of the dispersed data that existed at the national level. UNEP both in the climate and the health areas, succeeded in catalyzing and or supporting new systems for observations which were intended to reach gradually the global level. After a number of years of limited coordination between GEMS/PAC and the "Environmental Assessment", the Executive Director of UNEP, in 1979 when the post of Director of Environmental Assessment was vacant, decided not to fill this post but to make the Director of GEMS/PAC also Acting Director of Environmental Assessment. From that time the activities under GEMS/PAC became clearly coordinated with those under Environmental Assessment not only at the planning stage but also in day to day work. It also meant that the "Earthwatch concept" as defined in Stockholm in 1972 became the responsibility of only one person.

At this stage it is appropriate to mention the other programme elements of Environmental Assessment which from this stage became de facto elements also under the Earthwatch concept: INFOTERRA, the Programme on Outer Limits, IRPTC (the International Register of Potential Toxic Chemicals), Environmental Data and SOE (State of the Environment).

Although the above-mentioned elements were never clearly defined with respect to the four Earthwatch functions, it was assumed from this stage that GEMS was concerned with monitoring, evaluation and assessments; Outer Limits with evaluation and research; INFOTERRA and IRPTC with information and data exchange; Environmental Data with making monitoring and assessment data available for research, information and information exchange; and finally SOE with provision of information exchange at the political level. With these assumptions it was accepted that all the above elements were part of the integral Earthwatch activities within UNEP although the ultimate responsibility to provide assessments since its creation rested with the GEMS/PAC.

As to the function of the "Earthwatch" concept at the level of the overall UN system, it was somewhat unclear which role UNEP should play in addition to its catalyzing and co- ordinating function in general. The General Assembly, recognizing UNEP's coordination function (8), created in 1972 the Environmental Coordination Board (ECB) to be chaired by the Executive Director of UNEP under ACC in order to deal with environmental matters within the UN system. However the specialized agencies were not able to see why the environment should have a privileged status within ACC. Consequently in 1978 the ECB was abolished and since then the environmental matters were dealt with as any others by the ACC (GCIO/4 Add.l) (9).

As part of an attempt to combine the system-wide "Earthwatch" function with a thematic approach to environmental planning within the UN system, an Interagency Working Group on Earthwatch was established by UNEP in the mid 1970s, perceived originally as operating under ECB. As, however, the agencies found difficulty in using this body efficiently, its functions gradually faded out and thematic planning came to be dealt with by bilateral arrangements between UNEP and the agencies.

In-depth review of "Earthwatch", 1979-81

In 1979 the seventh Governing Council (GC7) session for the first time considered the problems related to the function of a system-wide Earthwatch and requested the Executive Director to make an in-depth review of how it operated and how it could be improved. The "Earthwatch concept" was defined by GC7 as a "dynamic process of integrated environmental assessment by which relevant environmental issues are identified and necessary data are gathered and evaluated to provide a basis of information and understanding for effective environmental management". As a result of GCs request, an ad hoc Group of Government- designated Experts met in Geneva in November 1979 to consider the development of mechanisms and procedures for environmental assessments within an operational system-wide Earthwatch.

The Group of Experts endorsed the general approach to the concept outlined by the GC7 and formulated the following more detailed steps that needed to be taken in any comprehensive assessment (10):

1. Description of the problem;
2. Review of available knowledge;
3. Establishment of the significance and priority of the problem;
4. Assessment of the effects (on humans, ecosystems, etc);
5. Description of available technology and methods for control;
6. Description of gaps in present knowledge and needs for further research;
7. Analysis of economic consequences; and
8. Conclusions on alternative courses of action for policy makers.

It was agreed by the Group of Experts that most of the assessment statements that had been made or were planned by UNEP/GEMS were not comprehensive in the above sense but rather preliminary assessments which indicated gaps that needed to be filled and further information to be collected. Repeated preliminary assessments would make assessments a reiterative process until ultimately a comprehensive assessment would be reached.

The in-depth review of Earthwatch which followed upon the meeting in November 1979 involved experts not only from UNEP but also from agencies and governments. The report of the Review consists of the following parts (11):

1. History of the environmental assessments in Earthwatch;
2. Outline of the conceptual basis of the assessment process;
3. Study of the commonalities of the assessment process in a range of environmental subjects;
4. Review of ongoing activities within three major sections of the environment (UNEP): (a) man's activities and their impact on him, (b) climate, (c) renewable natural resources;
5. Presentation of lists of assessments under way and of those which have been produced; and
6. Highlighting gaps in the international effort which was supposed to aid the thematic joint programming, at that time still going on in the Interagency Working Group on "Earthwatch".

The Review did not dwell on the quality of particular assessments or assessment products and considered the amounts of resources spent on assessments only in general or comparative terms. Resources allocated in the past period were comparatively low and it was made quite clear that if comprehensive assessments were to be made with the frequency that would be of use in decision making far more financial support would have to be provided than had been the case so far.

Through the analysis of the assessment efforts in the three areas - impact on man of environmental agents, climate and renewable natural resources - it became clear in the Review that the assessment function consists of two separate important efforts which cut across all sectors. They include first those activities which bring together or develop methodologies to collect or analyze assessment data and secondly those activities involved in actually doing the assessment.

The Review made it clear that an assessment is only as good as the data on which it is based and that data quality, comparability and representativeness all depend on the methodology used to build up the data base. In many cases data quality control, intercalibration and even the assessment methodology in general were at the time poorly developed and needed further development.

It was clearly stated at the end of the conclusions of the Review that the aim had not been to go into operational details of a future Earthwatch function; operational details would be worked out for each separate assessment project depending upon the agency, governments or regional authorities involved. In other words it was not foreseen to propose institutional arrangements for the Earthwatch function.

There seem to have been several basic reasons why an institutional structure for a system-wide Earthwatch did not emerge from this Review. At about the time when the review was made the specialized agencies did not regularly attend the meetings of the Working Group on Earthwatch and it was hence dying as an operational body. At about the same time (GC7) the system-wide medium term environment programme (SWMTEP) was created (12) as a main mean for harmonizing and coordinating environmental activities between UNEP and the remainder of the UN system. Although certain of the "Earthwatch concept" functions are clearly involved in the SWMTEP process there is no procedures outlined for a day to day function of a system-wide Earthwatch. Indeed SWMTEP gives only a clear picture of the "Earthwatch" function as internal activities of UNEP and the agencies. This makes it difficult to see how the system-wide function of Earthwatch was conceived during the period until 1990.

It is possible that the appointment of a new Director of GEMS and a new Acting Director of Environmental Assessment in 1983 implied that new approaches were taken to the institutional arrangements for a system-wide Earthwatch.

Second Phase 1982-1989

Governing Council summary of Earthwatch situation in 1982

Anyway the Governing Council in its special session to celebrate 10 years after Stockholm favourably summarized the progress under the concept of "Earthwatch" by looking at the achievements of the Action Plan for the Human Environment adopted at Stockholm. It noted that both GEMS and INFOTERRA were operating and expanding. IRPTC had started its functions as an important centre for information on toxic chemicals, and a major report on the State of the Environment 1972-82 had been published.

The 1982 special session of the Governing Council agreed also - without proposing any institutional structure for Earthwatch - that the main thrust of UNEP in the area of assessment during the next ten years should be to (13):

- improve early warning indicators;
- improve planning of the coordination of monitoring at the global and regional level;
- continue to produce concrete assessments for important environmental problems and their human impact;
- establish better links between GEMS, INFOTERRA, IRPTC on the UNEP side and national and international data centres on the other; and
- promote the development and establishment of reliable global, regional and national environmental statistics.

It is interesting to note that in the above listing of thrusts of Earthwatch after 1982 there is no direct mention of the need for a system-wide approach, although some system- wide activities are mentioned. Obviously this was interpreted by UNEP as implying that these thrusts should be carried out mainly as internal functions of UNEP.

In other words the operations and activities under the "Earthwatch concept" should continue with existing institutional arrangements. Hence, the "Earthwatch concept" from about 1984 was developed mainly within UNEP through activities of GEMS/PAC, INFOTERRA/PAC, IRPTC/PAC and the SOE under the leadership of the Director of GEMS/PAC who was also Acting Director of Environmental Assessment. The Interagency dimension did not exist as a standing function but was maintained through the SWMTEP procedure and through annual meetings of Designated Officials for Environmental Matters (DOEM) within the UN system which were organized by UNEP since 1983. At these meetings general approaches to environmental questions for the UN were discussed but no detailed planning or coordination of activities took place.

However the further development of the Earthwatch concept within the Environmental Assessment and PAC's function of UNEP did not mean that direct relations with the specialized agencies completely disappeared. In addition to the above-mentioned function of the DOEM meetings, the fact that many data gathering and monitoring activities were carried out by the agencies at the regional or global level necessitated regular detailed discussions and planning to be organized between UNEP and the relevant agencies. Over the years this cooperation led in several cases to useful results in the form of monitoring, gathering of information and ultimately to some form of assessments. The most well-known examples of comprehensive assessments are those made by UNEP in cooperation with WMO on the future of the ozone layer and on a possible global climate change. These were both handled in UNEP until 1980 within the "Outer limits" unit, later by the Atmosphere unit and were coordinated under Environmental Assessment. In those cases the system-wide approach to assessment has been well-looked after through close cooperation with relevant agencies (in particular WMO and ICSU). Governments were deeply involved throughout the development of the convention on the ozone layer and its later protocols (14). On the issue of climate change, governments became involved when the IPCC (Intergovernmental Panel on Climate Change) was launched by WMO and UNEP in 1987 (15). Both issues have, after comprehensive assessments, led to the ratification of framework conventions so that the ultimate management aspect is also well-taken care of (16). Other preliminary assessments have been made through cooperation of UNEP with other organizations or institutions: for the world's forest cover with FAO, for air quality in the world's megacities with WHO, as well as for the world's glaciers and ice masses with ETH in Zurich, etc. Ongoing, in cooperation with WMO, is an assessment of the problem of acid deposition in various regions of the world.

Data management in GRID from 1985

One interesting and important change in the UNEP mechanism for the Earthwatch function which had implications for the UN system took place in 1985 when the Global Resource Information Database (GRID) was established as a data management branch of GEMS/PAC. GRID provides an environmental data management service for UNEP, the UN system, international organizations and governments. (17).

By using a network of cooperating centres, GRID archives, collates and disseminates information in digital format, which has been extracted from maps, satellite images, statistical tables and other sources. All these data are linked together through computerized Geographic Information Systems and Image Processing Systems. The basic applications for users of GRID in addition to its data management function are:

1. helping to find environmental data;
2. support to environmental decision making;
3. regional environmental capacity building; and
4. supporting, analysing of national environmental capabilities.

At a more advanced stage GRID has been applied as a supporting function to environmental impact assessments. Thus, GRID plays and should play an important role in many of the functions foreseen in the original "Earthwatch" concept both at the internal level of UNEP and also for the whole UN system.

Of course a complicated system such as GRID was not easily established. It took about five years for GRID to find its proper role, and by that time it had grown by its own momentum into such a complicated operation that, although it still is an important supporting system for GEMS, it became a programme activity centre (PAC) for itself in 1991.

System-wide Earthwatch Development 1990-1995

Gradually it has become evident in the UN General Assembly (GA) that there is a need for a more systematic approach to the "Earthwatch" concept conceived at Stockholm. The Medium-term plan of the UN adopted by GA in 1990 for the period 1992-97 (45/253) reiterates that the "Earthwatch concept" should be considered one of the main pillars of the Action Plan for the Human Environment. As early as 1989 in the GA, resolution (44/224) on "International cooperation in monitoring, assessment and anticipation of environmental threats and in assistance in case of environmental emergencies" underlined the importance of broader participation in "Earthwatch" in order to strengthen its capacity to make authoritative assessments. In this resolution the Secretary General was requested, assisted by the Executive Director of UNEP, to prepare a report to UN GA, on the basis of the views of Member States and agencies, with recommendations on ways and means to strengthen the capacity of the UN:

- to monitor, assess and anticipate threats to the environment;
- to define criteria for determining environmental degradation;
- to issue early warnings on environmental threats;
- to facilitate intergovernmental cooperation in monitoring, assessing and anticipating threats;
- to assist governments facing environmental emergencies; and
- to mobilize financial resources and technical cooperation for the above purposes.

The above report was also requested to be submitted to UNEP's Governing Council.

The Executive Director of UNEP, in order to prepare such a report, called two meetings in July 1990 in Geneva and in February 1991 in Nairobi to develop ideas for this report. Outside consultants were hired to visit governments and specialized agencies to collect their ideas. The resulting draft report was sent to Heads of agencies for comments, finalized and presented to the Governing Council and further on to the General Assembly in 1991. GA noted the report (46/217) and asked that it be conveyed for further consideration by the Preparatory Committee of UNCED in 1992.

The Governing Council in 1991 further elaborated on the needs for a strengthened system-wide Earthwatch and recommended that Earthwatch (18), in keeping with its original mandate, should identify global and regional environmental monitoring and assessment needs, coordinate and harmonize global, regional and national monitoring and assessment programmes to the extent required, prepare comprehensive assessment statements and inventories, give advanced warnings on environmental threats, as well as suggest policy responses and management options.

Agenda 21 from UNCED (19) in Rio in 1992 further underlined the need to strengthen "Earthwatch" as an essential component in assembling information on the environment, relating it to sustainable development and delivering it to decision makers. More specifically it stated that UNEP should be strengthened to promote environmental monitoring and assessment both through improved participation by the UN agencies in the Earthwatch programme and by expanded relations with private scientific and non-governmental research institutes; UNEP should also strengthen and make operational the early-warning function of Earthwatch.

With the above-mentioned developments over the last three years, there can hardly be any doubt that the UN has taken very clear steps to call for the "Earthwatch" concept to become institutionalized in such a way that the whole UN system together with governments will participate efficiently in a process to collect, evaluate and assess the state of trends in the global environment.

The Executive Director of UNEP, in following up this development, named a high- level Coordinator and a Deputy Coordinator of Earthwatch in late 1991 who inter alia have worked on implementing the recommendations and resolutions from the GC and GA which have emerged over the last few years.

The GC in 1993 at its 17th session discussed extensively the need for an in-depth study of "Earthwatch" which was carried out by UNEP in 1994-1995, and led to the ACC report on the United Nations system-wide Earthwatch in 1995.

The GA 48 in 1993 finally in its resolution 193 (20) reaffirmed the decisions of Agenda 21 and the Rio declaration. It further emphasized the importance of the participation of specialized agencies and other organizations of the UN system in Earthwatch, in particular in its environmental monitoring programmes and the need for early-warning capabilities in these programmes. It also invited Governments and relevant organizations of the UN system, within their mandates, to review their contribution to international cooperation in environmental monitoring including remote sensing and data assessment and to provide relevant support. It finally requested the Executive Director of UNEP to prepare and submit to the GC of UNEP a report on the programme activities in environmental monitoring containing proposals and recommendations for activities within the context of Agenda 21 and a review of Earthwatch, taking into account the decisions of GC of UNEP at the 17th session, in cooperation with relevant entities within the UN system.

This resolution from GA 48 seems to call for an in-depth study of the development of the concept of Earthwatch to include proposals for future institutional arrangements for a system-wide Earthwatch including contributions from Governments to the monitoring and assessment functions.

If we at last look at the recent developments of the needs for a system-wide Earthwatch to materialize in a more concrete form in comparison with the original concept from Stockholm, there is essentially one difference. The need for a global approach, emphasizing the requirement to concentrate on environmental issues which will or may have an impact on all countries and therefore must be managed and considered in achieving sustainable development by all governments, is still clear. However, it has become obvious that the processing of available information and the filling of gaps in monitoring of the environment, as well as in producing assessments on global issues, would require the participation of governments to a larger degree than was thought twenty years ago. Experience has shown that participation from all countries is essential for any system to reach globality. Consequently capacity building in the developing countries to make it possible for them to participate in a global monitoring and assessment process should become an essential part of any institutional arrangement to be developed for an "Earthwatch" system comprising the entire world.

1. See "An Action Plan for the Human Environment", chapter IV, para. 67-77. Report on Conference on Human Environment, Stockholm, 1972, A/Conf.48/5.

2. "Report of the Governing Council of the UN Environment Programme", first session, Geneva, 1973, para. 13-87.

3. Global Environment Monitoring, SCOPE report, 1972.

4. Intergovernmental Working Group on Monitoring Meeting, Geneva, August 1971.

5. Report of Intergovernmental Meeting on Monitoring, Nairobi, 1974.

6. Report of Governing Council of UNEP, third session, Nairobi, 1975, item 7b of agenda.

7. Report of Governing Council of UNEP, third session, Decision, p. 16 of text on GEMS.

8. UN General Assembly report of twenty-seventh session, Res. 2997.

9. Report of Governing Council of UNEP, seventh session, General Debate, para. 83-86; Decision 7/4.

10. Report on "In Depth Review of Earthwatch", 1981.

11. Report on "In Depth Review of Earthwatch", 1981.

12. Report on Governing Council of UNEP, seventh session, Decision 7/II.

13. Resolution IV of Governing Council at its session of a special character, 10-18 May 1982.

14. Vienna Convention on the Ozone Layer, Vienna, 1984; Montreal Protocol to Vienna Convention, Montreal, 1986.

15. Report of Governing Council of UNEP, fourteenth session, 1987, Decision 20.

16. UN Conference on Environment and Development, Rio de Janeiro, June 1992, Decision.

17. Report of Government Council of UNEP, thirteenth session, 1985, Report of the Executive Director, p. 8.

18. Report of Government Council of UNEP, sixteenth session, 1991, Decision 16/37.

19. UN Conference on Environment and Development, Rio de Janeiro, 1992.

20. UN General Assembly, forty-eighth session, 1993, Resolution 193.