Recognizing the need for specific and technical input concerning terrestrial observations for climate purposes, the sponsoring organizations of GTOS and the GCOS have jointly established TOPC with the following terms of reference:

1. To define the requirements for long-term monitoring of terrestrial properties for climate and climate change

2. To liaise with relevant research and operational communities to identify measurable terrestrial (biosphere, cryosphere, and hydrosphere) properties and attributes which

• control the physical, biological and chemical processes affecting climate
• are themselves affected by climate change, are indicators of climate change and provide information on impacts of climate change

1. To assess and monitor the adequacy of terrestrial observing networks (in-situ, satellite-based), promote their integration and promote the development of their capacity to measure terrestrial properties and exchange climate data and information

2. To identify gaps in present systems and design, promote and periodically revise plans for a long-term systematic observing system that fills these gaps, makes the data available and so better serves the needs of the research and operational communities

3. To coordinate activities with other global observing system panels and task groups to ensure consistency of requirements with the overall programmes

4. Publish and update GCOS/GTOS studies and planning documents

5. To liaise with the other GCOS panels, WCRP steering groups and other relevant entities, such as WMO Commissions and CEOS, on terrestrial climate observing system issues., and also to other GTOS panels, where relevant

6. Carry out agreed assignments from the GCOS and GTOS Steering Committees

7. Report regularly to the GCOS Steering Committee and GTOS Steering Committee on issues related to the terrestrial component of GCOS