In 1995, the climate and terrestrial components of the Global Observing Systems joined to form the Terrestrial Observation Panel for Climate (TOPC). To assure coordination between the climate and terrestrial components of the observing system, TOPC has completed and published a Plan for Terrestrial Climate-related Observations which includes elements of hydrosphere, cryosphere, and biosphere.

The strategy for implementing the plan is under development in conjunction with the World Climate Research Programme (WCRP). Hundreds of variables are possible candidates for global climate monitoring. Potential sampling locations range in the thousands. It is neither feasible nor desirable to measure everything, everywhere, all of the time. The panel has therefore developed a list of variables for monitoring and developed a sampling design for the ecological variables. TOPC welcomes your comments and feedback. If you have comments on the list of variables, gaps or redundancies please contact us.

During the early years, TOPC concentrated on the planning and design aspects of its mandate. It designed a five-tier observation strategy; the Global Hierarchical Observing Strategy (GHOST).

Over the past two years, TOPC emphasis has shifted towards ensuring long-term global observations of critical variables. These activities include:

1. Development of terrestrial observation networks. In situ networks provide critical data for modelling and applications, developing algorithms that make satellite data meaningful, and validating its measurements. TOPC builds on existing global or regional networks, harmonizes their efforts as much as possible and improves the quality of climate-related observations.

2. Thematic networks have been established for ecology, glaciers, and permafrost. A hydrology network is in process and regional networks are being formed for Central and Eastern Europe, Southern and Eastern Africa, and Southern Asia.

3. Pilot projects. TOPC actively supports the development of pilot projects such as the Net Primary Productivity (NPP) and Global Observation of Forest and Land Cover Dynamics (GOLD). The panel is also closely involved in the Global Land Ice Monitoring System (GLIMS). These projects initiate and strengthen the mechanisms for long-term observations.

4. Standardizing satellite data requirements. The use of satellite data requires a sequence of processing and modelling steps. TOPC has standardized each step in accordance with the CEOS database (the database is currently managed by the WMO).

5. Identification of global data sets. TOPC identifies global data sets for climate-related terrestrial applications. These data sets are then added to the Global Observing Systems Information Centre (GOSIC), making them more widely accessible and useful.