Report on the WCRP JSC Meeting
Toulouse, France, March 11-16, 1996.

The Joint Steering Committee (JSC) of the World Climate Research Programme (WCRP) met in Toulouse, France. M.-L. Chanin attended this meeting and presented the activities of the SPARC programme, as well as the recent major scientific results of concern for the SPARC community.

Extensive discussions were triggered by the release of the second full IPCC Assessment Report which concluded that "the balance of evidence suggests a discernible human influence on global change" but that there were still a number of uncertainties. Contribution of WCRP to help resolve the main uncertainties identified in the report was a subject of concern and discussion for the JSC.

One of the urgent needs is to better identify an Anthropogenic Climate Change Signal in the variability which could be partly explained by purely natural causes (solar, volcanic). In that line, and to complement near-surface parameters, a better knowledge of the change in the vertical profile of atmospheric temperature, which has been suggested for a long time as a possible "fingerprint" of greenhouse-gas induced climate change, was clearly stressed at this meeting. In one of the two lectures given during the meeting, B. D. Santer (LLNL) concluded that numerical simulation of such vertical changes needs to consider simultaneously change in CO₂, stratospheric ozone and anthropogenic sulphate aerosols, and that climate change detection investigations ignoring O₃ effects are likely to be unsuccessful. The contribution of SPARC on the stratospheric aspect of this issue is already approached by several SPARC initiatives from both the modelling aspect and the determination of trends in the vertical profiles of temperature, ozone and other minor species.

Liaison between SPARC and WGNE which could be achieved through GRIPS was highly praised, as well as a connection with CLIVAR which is focused on the identification of the source of variability in climate of both natural and anthropogenic nature.

A recommendation was again made for continuous monitoring of atmospheric concentrations of gases playing a main role in either the greenhouse problem or the ozone issue. The cooperation of SPARC with GAW and IGAC and a close connection with NDSC were encouraged.

A large WCRP Conference was announced to be held in 1997 aimed at considering WCRP priorities in the light of the IPCC 1995 Report. It would present the relevance of the research carried out by the different programmes to the expectation of society and set the priorities and objectives for the next 10-15 years. SPARC was asked to contribute to the preparation of this Conference.

Marie-Lise Chanin

Co-chair of SPARC