The Global Climate Observing System (GCOS) completed an international assessment – Second Report on the Adequacy of Global Observing Systems for Climate in support of the UNFCCC – and presented the Report to the 18th session of the UNFCCC's Subsidiary Body on Scientific and Technological Advice (SBSTA) in June 2003. The primary conclusion from the Report states that – Full commitment and cooperation by all nations is essential in building a comprehensive coordinated global observing system, using a mix of high-quality satellite and in situ measurements, dedicated infrastructure, and targeted capacity-building. Further, SBSTA “noted that the second adequacy report provides an opportunity to build momentum among governments to improve the global observing systems for climate, …”

Four high priority, overarching areas for action have been identified for implementing improvements.

1. Capacity Building and System Improvements: Enabling the developing countries to sustain key measurements is essential to a truly global climate observing system. An important priority for developed (and some developing) nations is to make a commitment to improving the baseline systems and establishing essential reference sites nationally as well as in developing countries, especially in the least developed countries and small island developing states. A voluntary funding mechanism to support high-priority stations in developing countries, especially the least-developed countries and small-island developing states will be discussed.

2. Data availability and Observing Standards: Free and unrestricted exchange of data: is an absolute necessity for generating products (datasets, predictions, assessments, etc.) to respond to global and regional societal issues. For climate change, GCOS has proposed a set of essential climate variables1, which nations must exchange to meet the needs of climate users and the UNFCCC.

In addition, obtaining climate-quality data will require adherence to the GCOS monitoring principles by data providers and the establishment of internationally accepted observing standards, especially for the terrestrial domain, if long-term climate and environmental change is to be observed. Actions being taken internationally on these complex issues will be outlined.

3. Sustained Availability of Integrated Global Products: from combined satellite and in situ observations and / or from the re-analysis of homogeneous historical data would be a major advance in meeting the needs of specific users, such as the UNFCCC. This will be discussed in another paper.

4. Full development of observing networks in the atmospheric, oceanic and terrestrial domains: Specific deficiencies in the domain based in situ observing networks are being identified by GCOS and its partners. The scientific requirements will be discussed in another paper.

This paper will discuss specific actions that GCOS in partnership with interested countries and international organizations will be taking to implement the major conclusions and recommendations arising from the report, especially on system improvements in developing countries, international actions on observing system standards, and data exchange.