The Global Climate Observing System (GCOS) is preparing an international assessment -Second Report on the Adequacy of Global Climate Observing Systems - for the UN Framework Convention on Climate Change (UNFCCC). This second Adequacy Report will be presented to the 18th session of the UNFCCC's Subsidiary Body on Scientific and Technological Advice (SBSTA) in June 2003. SBSTA encouraged GCOS to complete the final report on an expedited schedule both "to provide a framework for further work to improve global monitoring systems" and "to enable substantive consideration of the report at the ninth session of the Conference of the Parties (COP) in late 2003.

Background GCOS prepared its first assessment of the Adequacy of the Global Climate Observing System for the 4th session of the UNFCCC Conference of the Parties (COP-4) in 1998. This report investigated the common assumption "that there are more than enough observations being collected to meet these [the Convention's] needs, especially given all the recent improvements in observational technologies. In practice, available observations often have major deficiencies with respect to climate needs." Such deficiencies were clearly raised by the IPCC in its 3rd Assessment Report (TAR) as critical to improving future understanding of climate change. The second Adequacy Report is in direct response to decision 5/CP.5 of the UNFCCC Conference of Parties. This decision invited all Parties to provide detailed reports on systematic observation in accordance with the UNFCCC reporting guidelines on global climate observing systems and requested the UNFCCC and GCOS Secretariats "to develop a process for synthesizing and analysing the information submitted".

Discussion of policy issues The paper will discuss the policy drivers behind the report and the scientific and strategic goals of the report. The process that was put in place sought to satisfy the competing goals of broad scientific ownership of the adequacy process and the institutional demands of completing the report within a timeframe that would be useful to the UNFCCC and its Parties, the international Sponsors of GCOS and the scientific community interested in the global observations of climate.