Comparing screening outcomes of national and global biodiversity datasets for private sector nature-related disclosures

In response to demand for better biodiversity stewardship from the private sector, frameworks such as the Taskforce on Nature-related Financial Disclosures (TNFD) have been developed to help companies assess, manage and disclose their nature-related impacts, dependencies, risks and opportunities. A key initial screening step is to identify operations in ecologically sensitive areas, often done using global datasets that are readily available and globally consistent, but may be less accurate that national data informed by local expertise and conditions. In this study, we explore the implications of using global or national biodiversity datasets for identifying ecologically sensitive sites at large scales, using South Africa as a case study. We simulated a screening process by generating ‘sites’ through stratified random sampling, and screening these based on three TNFD criteria for ecologically sensitive sites: biodiversity importance, high ecosystem integrity, and rapid decline in ecosystem integrity. We compared results from multiple global and national datasets, calculating omission errors, where global datasets omit sites identified by national data, and commission errors, where global datasets flag sites as sensitive but national data do not. We found global datasets missed between over 39% of areas important for biodiversity, as identified by national datasets. This risks ongoing biodiversity loss, because sites omitted at early screening stages are unlikely to have resources allocated for conservation or restoration. Our findings suggest a cautious use of global datasets, with an emphasis on encouraging the use of national datasets, particularly when fine-scale, field-validated, and frequently updated data are available.