A steering trustee is an organisation / establishment that contributes to the overall vision and strategy of IPSL and provides significant resources for IPSL's missions in the federation. The steering trustees meet two or three times a year with the IPSL management, and review the progress of IPSL's missions, and the human and financial resources required by the work plan.

Once a year, IPSL distributes an activity report for the year gone by and an action plan for the year ahead to its main trustees. The IPSL reviews the strategic climate issues at the national and international level, new programmes and proposals for international collaborations with its trustees. These trustees decide on shared resources for the federation and the laboratories for these missions, means which will have been jointly discussed and proposed by the IPSL and the laboratories.

IPSL will propose to the group of steering trustees a coordination of all activities, with the scientific activities or themes being allocated by supervisory authority to allow interesting agreements that benefit from the best expertise for the benefit of the scientific community.