This document brings together the results of two different approaches to impact evaluation. The first is a theory-based mixed-method approach, which was built on detailed documentary review, exploration of the concept of impact in the context of intended effects on the global environment, methodological development through regional workshops at which project implementers themselves devised and tested theories of change for their projects, detailed fieldwork in project areas to verify and explain the results achieved, and extensive analysis and interpretation during which the theories of change were tested against actual results to determine project impacts and how they had been achieved.