According to a strict set of inclusion and exclusion criteria, the evidence gap map (EGM) is derived by systematically and exhaustively reviewing high-quality evidence from evaluation, research, peer-reviewed and grey literature.

Specifically, the EGM:

• Provides a robust typology of eight sectors, 11 intervention types and three outcome groups that serves as a conceptual tool for defining the objectives of further studies and for locating interventions more accurately
• Provides an accessible overview of evidence from systematic reviews, impact evaluations and rigorous quantitative studies
• Highlights available evidence and their characteristics, such as confidence ratings of systematic reviews
• Allows users to explore the evidence base and findings of relevant studies
• Structures relevant intervention actions and outcomes within a framework
• Populates areas with available studies and reviews while highlighting “absolute gaps” related to impact evaluations and systematic reviews

The EGM identifies 32 papers that are mapped onto a conceptual framework that includes the type of intervention, the sector of activity and types of outcomes measured. Most studies use quasi-experimental designs and multivariate analyses.

The results show that a large share of the available evidence is in the energy and industrial sectors, and within them, on the effectiveness of fossil fuel substitution and energy efficiency measures. The main gaps include a scarcity or absence of evidence regarding building and urban planning, reforestation/afforestation, and anti-desertification measures. Soil and fertilizer management is also absent from the evidence gathered for the agricultural sector. There is also a scarcity of studies that examine employment co-benefits and intermediary outcomes such as behavioural change.

We also compare the available evidence with the GCF´s project/investment portfolio in the form of an intervention heat map, which indicates whether the portfolio operates in evidence-rich or evidence-scarce fields. This shows that much of the portfolio covers energy-related interventions where the EGM has highlighted several relevant studies (albeit spread out over a range of mitigation, intermediate and co-impact outcome areas). Investments in industry, transport, agriculture, and forestry and land management are in sectors where the EGM has highlighted a limited number of studies (especially transport, with only one single piece of evidence). Investments in buildings are in a sector where the EGM found no studies.