Location: United Kingdom
Primary stakeholders: National and local policy makers (UK government and local councils), private sector
Sector/industry: Infrastructure development
Primary extractive or damaging activities: Habitat conversion and land use change
Affected ecosystem(s) and biodiversity: All natural habitats in the UK
Goal: Biodiversity Net Gain (BNG)
Metric: Natural England’s “Biodiversity Metric 2.0”, a composite indicator that converts inputs including the area, habitat condition, habitat distinctiveness, and various types of risk multipliers for each habitat patch into an overall biodiversity score measured in ‘biodiversity units’.
Stage of implementation and associated outcomes: Planning stages – the policy is expected to be ratified in early 2021, with mandatory BNG introduced after a two-year transition period. However, several councils have adopted BNG-equivalent policies in advance of its national rollout. Preliminary outcomes suggest BNG-equivalent polices are associated with a 21% loss in non-urban habitat area, but a predicted 17% increase in biodiversity units via higher condition (but smaller) habitats in the future if all developer commitments materialise as planned (see zu Ermgassen et al. 2021 for details).
Needs and next steps:Given developers are promising smaller, but higher quality habitats in the future, it is essential that the way that ‘quality’ is measured is robust, so the Biodiversity Metric requires further field testing and modification. Also, a preliminary evaluation identified important governance gaps which mean that most of the biodiversity gains may be unenforceable; these need to be address to ensure policy compliance is high (zu Ermgassen et al. 2021).
Key references and resources:
- Zu Ermgassen et al. 2021: Exploring the ecological outcomes of mandatory Biodiversity Net Gain using evidence from early-adopter jurisdictions in England
- Balfour Beatty’s set of Good Practice Principles for infrastructure development to achieve Biodiversity Net Gain (2016)
- Balfour Beatty’s Roadmap for the UK’s infrastructure development to achieve Biodiversity Net Gain (2018)
- Natural England’s Biodiversity Metric 2.0
“Biodiversity Net Gain (BNG) means thats development leaves biodiversity in a better state than before. It is also an approach where developers work with local governments, wildlife groups, land owners and other stakeholders in order to support their priorities for nature conservation…
Apply the mitigation hierarchy: do everything possible to first avoid and then minimise impacts on biodiversity. Only as a last resort, and in agreement with external decision-makers where possible, compensate for losses that cannot be avoided. If compensating for losses within the development footprint is not possible or does not generate the most benefits for nature conservation, then offset biodiversity losses by gains elsewhere.”
– Biodiversity Net Gain Good practice principles for development. CIEEM, CIRIA, IEMA, 2016.