It is evident that a solid foundation of data is necessary for the different assessment processes for environment and development. We must avoid the situation where parts of the UN use different, sometimes conflicting, data on the same topic. Such discrepancies lower the credibility of all UN assessments. These differences may come from inconsistent national sources, the lack of standard methodologies and definitions, estimations and gap filling to complete data sets, or insufficient harmonisation and quality control. All data collectors have struggled for years with these problems. 

There are already some effective inter-agency responsibilities in this area. The ACC Subcommittee on Statistical Activities is addressing problems of inconsistent data sets, harmonization and electronic distribution insofar as they concern statistical data, but this effort does not cover much scientific or spatially georeferenced data. For indicators, DESA-DSD has taken a lead in the CSD indicators process to identify a core set of indicators of sustainable development, while UNSD has been working to harmonize development indicators. OECD is also working to define core sets of indicators for its member countries. A United Nations Geographic Information Working Group has recently been established under the CCPOQ (see summary in annex). These bodies still leave some gaps in coverage, such as for spatially-referenced data sets for use in Geographic Information Systems, for data on many natural resources and environmental parameters, and for data not falling within the scope of statistics. 

Most of these processes are driven by data producers aiming to improve the delivery of their products. Yet general purpose databases, while important, are not particularly useful for addressing the key policy questions in UN assessments. What is still lacking is a mechanism for data users in the major international assessment and reporting processes to harmonize their requirements for common global data sets relevant to the questions they need to address. Some of these will be common to all the assessments and can be considered core data sets; others will be specific to the needs of a particular organization. Each organization presently assembles its own data sets from those sources it considers most reliable or accessible, because each requires data tailored to its particular needs. UNEP, for instance, is presently assembling the global data sets needed for the Global Environment Outlook (GEO-3) report, in the context of the environmental policy issues and trends to be addressed in that report. Other agencies do the same for their own specific interests. 

There is a particular gap in data sets providing adequate spatial and temporal coverage to identify trends and distribution. Most global data sets are still very poor in these respects. By identifying the common core data sets required for a number of assessments, efforts could be combined to improve the data available. 

UNEP and the Division for Sustainable Development organized a first meeting on common core data sets in New York in 1996. This meeting prepared a first matrix of core data sets and the agencies responsible, but much of the follow-up agreed at the meeting did not materialize. In response to the difficulties faced again in assembling data for the GEO-2000 report, the issue was raised once more in the Earthwatch Working Party in 1998, and with the encouragement of the IACSD, a technical meeting was programmed for mid-2000 to update the matrix of core data sets, before being postponed to adjust the purposes of the meeting in the context of new developments. In fact, the rapid evolution of information technologies has overtaken the original concept of a data set matrix and changed the perspectives for solutions to this problem. Down-loading of data sets from Internet sites has become routine. On-line access to complete geographic information systems has become possible. Within a very short time, technology has eliminated the physical limitations to the access to and distribution of core data sets, although the challenges of data collection and harmonization remain. Even here, the prospects of decentralized data collection motivated by the rapid return of value added information products will make more complete and timely information systems possible. 

It is now technically possible to conceive of a distributed information system with multiple portals where each agency maintains its own core data sets, while making it possible to combine all of them integrated in multiple data layers. Such a system could generate maps, models or decision-support tools on demand. UNEP now intends to pioneer the development of such a Global Environmental Information System with NGO and private sector partners. We hope to have a pilot system for UNEP's own assessment data needs as a operating model within a few months. Once we have something concrete and practical to propose, we shall open it to all our UN system partners in Earthwatch. The timing will then be right to meet to discuss common core data sets and their inclusion in such electronic information systems. We shall keep you informed as our new initiative develops. 

As an intermediate step, and in preparation for the discussion of information for decision-making at CSD-9, we are up-dating the summary descriptions of the data and information activities of our UN system partners on the Earthwatch web site (http://www.unep.ch/earthw.html). The present pages have been reformatted and simplified, but some of the entries still date back to your submissions to the Task Managers in 1994. We should like your cooperation to update your material and to provide us with much more complete links to the relevant parts of your own web sites. The Earthwatch site could then link users directly to your sources of core data sets, maps, indicators, models, scenarios and other information for decision-making. The UN System-wide Earthwatch can become an integrated point of access to the UN system activities and information holdings by type of information activities and by programme areas of Agenda 21, in complement to the country information on the sustainable development site maintained by DSD. It will then be easy to see who is doing what, and where different core data sets are located. The Earthwatch web site and related sites for the Integrated Global Observing Strategy (IGOS) Partnership, the International Coral Reef Action Network (ICRAN) and UNEP Islands maintained by Earthwatch have become convenient on-line filing systems for relevant documentation and access to other sites. 

Another relevant Earthwatch activity worth mentioning is the completion shortly of the Second Report on International Scientific Advisory Processes on Environment and Sustainable Development, which we were asked to complete and up-date after the first report provided useful material for the CSD review of science in 1998. The preparation of this report was first suggested at the IACSD.