GIWA is one of four global assessments. Others have already been made on biological diversity, climate change, and the ozone layer (stratospheric ozone) for the purpose of supporting the implementation of the Global Environment Facility, GEF, project portfolio in these areas. GIWA is intended as a comparable asessement in support of the implementation of the international waters component of GEF.

Biodiversity
The objective of the Global Biodiversity Assessment, which was commissioned by UNEP, funded by GEF, and released in 1995 at the second meeting of the Contracting Parties to the Convention on Biological Diversity (the Jakarta Meeting; see the Jakarta Mandate), was to "provide an independent, critical, peer-reviewed scientific analysis of the current issues, theories and views regarding the main global aspects of biodiversity".

In this comprehensive report, the critical scientific issues were examined in detail and attention was drawn to gaps in knowledge and the issues where uncertainty has led to alternative viewpoints which will require further research to resolve.

The Global Biodiversity Assessment could shape the scientific agenda for the next decade and be the starting point for future assessments within the framework of the Convention to provide a sound basis for policy-making. One major conclusion was that biodiversity management must go far beyond simply establishing isolated nature reserves or setting up agricultural seed banks. Instead, it must be fully integrated into all aspects of landscape management, including agriculture, socio-economics, and other relevant fields.

Climate change
Two international assessments on climate change (see info on reports and summaries) have been made within the framework of the International Panel on Climate Change (IPCC).

The First Assessment Report was completed in 1990 and played an important role in establishing the Intergovernmental Negotiating Committee for the UN Framework Convention on Climate Change, which was adopted in 1992 and entered into force in 1994. It provides the overall policy framework for addressing the climate change issue.

The Second Assessment Report of the IPCC - Climate Change 1995 - provided key input to the negotiations, which lead to the adoption of the Kyoto Protocol to the UNFCCC in 1997 (see info on reports and summaries). The Third Assessment Report currently under preparation will be a comprehensive and up-to-date assessment of the policy-relevant scientific, technical, and socio-economic dimensions of climate change. It will concentrate on new findings since 1995, pay greater attention to the regional (in addition to the global) scale, and include non-English literature to the extent possible.

Stratospheric ozone
The current understanding of ozone depletion and its relation to humankind is discussed in detail by the leading scientists in the world's ozone research community in the WMO/UNEP Scientific Assessment of Ozone Depletion 1991, 1994 and 1998 (with contributions by the National Oceanic and Atmospheric Administration, National Aeronautics and Space Administration, and the European Commission).

Three Assessment Reports were made during 1998 as part of the information upon which the Parties to the UN Montreal Protocol at the meeting in June 1999 based their decisions considering the need to amend or adjust the Protocol. The reports included the present scientific assessment focus on the environmental and health effects of ozone layer depletion and on the technological feasibilities and economic implications of various mitigation approaches. Altogether there have been eight scientific assessments prepared under the international auspices of the World Meteorological Organization (WMO) and/or UNEP.