NbS Triple Win Toolkit: Biodiversity Indicators in Context 35 available local data and global datasets. However, the spatial resolution of land cover, elevation and species range data may limit applicability in smaller projects. Smaller projects may have negligible impact to the STAR score for broad-ranging species for example, as the proportionof the available AOH for that species within the project will be small. The calculated reduction in threatened species risk can be aggregated at the programme and portfolio level. One STAR unit is approximately equivalent to the reduction in extinction risk of one species by one threat category37. Alternatively, the output can be communicated asa potential percentage of contribution to averting extinction risk forall species in e.g. recipient countries, or all ODA-eligible countries. Limitations and Challenges Data restrictions The method is dependent on the IUCN Red List for species status, range, habitat associations and threat details. While the global range and availability of these data are important advantages to the indicator, the current coverage of the Red List limits the scope of the indicator metric to sufficiently documented species. At present the method cannot address emerging or worsening threats well, as information on how these may change a species extinction risk will only be made available through Red List re-assessments. The indicator can be generated using global land cover data to estimate available AOH for species, but where available local data would improve the resolution and accuracy of these estimates. It is recommended that global data layers, including the Red List species range estimates, are validatedby local observations or field data if available. Communication The output unit of the indicator may not be self-explanatory. One STAR unit roughly equates to the reduction in extinction risk of one species by one category, though units can be decimal, and depending on the coverage of the programmes, may be considered small. The unitscan also be presented as a percentage of total contribution of species’ threat removal in a given area. The concept of comparing project STAR scores to counterfactual scenarios, such as sites of the same ecosystem type and land use not benefitting from ICF funding and conservation activities or modelled scenarios, was suggested39 butthis idea requires further development and research to assess the validity and applicability. Discussion point: Decision on best units for communicating reduction in threatened species extinction risk. For example the value could be reported as a ICF’s contribution to averting extinction risk as a percentage of all species in ICF receiving countries, or, as a rawnumber with the clarifier “1 = the reduction of 1 species by 1 threat level.” Scope At present only terrestrial ecosystems have sufficient global Red List data to have been included in the globally generated STAR estimates, and within terrestrial systems only amphibians, birds and mammals are currently included. The scope is expected to expand to other taxa as more data become available, with likely candidates for imminent inclusion comprising reptiles, cacti, cycads, conifers, freshwater fishes and reef-building corals. The inclusion of freshwater fishes will then make this a suitable indicator for freshwater systems; however it is unlikely to be an adequate indicator for marine systems (beyond marine mammals and birds) other than where a project is directly related to a coral reef system (for a review of more broadly applicable indicator options for marine environment, see marine indicators in context).