Earmarked contributions and payments to trust funds are made by Governments, United Nations agencies, other organizations, non-state actors and individuals, for specific programme activities, services and facilities for individual projects. Trust funds at UNEP are earmarked by donors for specific purposes.

The biggest trust fund is the one for the Multilateral Fund under the Montreal Protocol on substances that deplete the Ozone layer, for which UNEP’s role is largely that of treasurer. The general-purpose trust funds provide financial resources for activities supporting the programme of work of UNEP as well as of conventions and regional seas programmes and the activities of their secretariats. The Technical Co-operation trust funds are used to facilitate technical assistance to developing countries and also for financing personnel through Junior Professional Officer Programmes and the secondment of staff from donor countries. Trust funds often have a different governing structure from that of the Environment Fund, may be bilateral or multilateral and are accounted for separately.

The total number of active trust funds has increased from 74 in 2003 to 84 in 2010, comprising of 52 trust funds in direct support of the UNEP Programme of Work, and 32 trust funds supporting Conventions, Protocols and Regional Seas.

In 2008-2009 UNEP received US$233.3 million in earmarked contributions, including counterpart contributions and trust funds directly supporting UNEP’s programme of Work. The GC25 approved the indicative level of US$228 million for earmarked support in the current biennium of 2010-2011.