Accounting for GEF’s additionality—the unique benefits attributable to its financing—remains a persistent challenge.

The concept is central to demonstrating GEF’s value, yet project design and reporting often fail to distinguish what GEF support adds beyond partner agency actions. This evaluation proposes an approach that strengthens measurement of additionality while aligning with the evolving nature of GEF projects and results frameworks.

Assessing GEF’s environmental additionality cannot be measured through a one-size-fits-all approach.

Evaluation overview

• Barriers include weak application of incremental reasoning, lack of quantitative baselines, and generic reporting that limit clarity on GEF’s contribution to global environmental benefits.

• Clearer evidence of additionality emerges at project closure, but innovation and other forms of added value are seldom identified. Strong theories of change better capture long-term influence when direct attribution is limited.

• The report recommends strengthening theories of change, revising evaluation policy and terminal evaluation guidelines, and systematically tracking broader dimensions of additionality, including legal, institutional, financial, socioeconomic, and innovation factors.

Methodology

Evidence comes from portfolio review, literature, and classification of additionality across environmental, legal, institutional, financial, socioeconomic, and innovation dimensions.