Infrastructure projects pose one of the most significant threats to global biodiversity, and biodiversity loss is a critical threat to maintaining a habitable planet. With England’s new Biodiversity Net Gain (BNG) law, should we look forward positively to a future where development and nature coexist harmoniously?
The United Kingdom government targets building 300,000 new homes annually by the mid-2020s. Under the new rules, land affected by these developments must be compensated. Each development must achieve a 10% net gain in biodiversity or habitat. For example, woodlands destroyed by a road must be recreated either on the same site or elsewhere. In principle, this should boost the country’s heavily denuded natural capital for 30 years after the completion of the development.
This new scheme could restore many habitats. “The scheme will make people think about how to minimize and mitigate the ecosystem impact of new developments,” said Natalie Duffus, a researcher from the University of Oxford who analysed the impact of BNG trials on conservation.
However, how will this unfold? Tom Oliver, a professor of applied ecology at the University of Reading, highlighted that the law implements a new approach relying on mechanisms that often do not work effectively. He stated, “BNG’s success hinges on effective environmental regulation, monitoring, and policing. Yet, our past case studies show a clear failure of environmental enforcement and policing.”
Interchangeability of Habitats
Can one type of habitat be directly interchangeable with another? The new law introduces the statutory biodiversity metric, which converts the habitat’s size, type, and quality into standardized biodiversity units. Whatever the number of units that existed before development, there must be 10% more afterward. For instance, if a site contains a habitat of a hundred units, there must be 110 units post-development, even if it is a completely different habitat. This metric’s flaw lies in the fungibility of biodiversity.
The concept of biodiversity offsetting is like carbon offsetting, which allows activities emitting greenhouse gases to be compensated elsewhere, for example, by planting trees. However, biodiversity offsetting presents more significant challenges. Graham Lawton of the New Scientist explains that while carbon offsetting is theoretically sound, it faces multiple practical issues. Biodiversity offsetting permits the destruction of biodiversity in one area to be offset by preservation in another. The steps typically follow this sequence:
- Avoid destroying biodiversity.
- Reduce unavoidable impacts.
- Remedy on-site by restoring what has been lost.
- Offset to make up the gap.
Zu Ermgassen, an environmental economist at the University of Oxford, noted that “more than a quarter of BNG units are at risk of leading to no tangible increases in biodiversity because there is no monitoring system in place.” Concerns also exist about the number of ecologists available to oversee or score habitats correctly, some of whom may lack independence if employed by developers.
Addressing Greenwashing and Flaws
According to Lawton, the new law “invites greenwashing and is deeply flawed.” The most credible way to bridge the gap is for governments to enforce actions through incentives or penalties. In this respect, England’s new law is a step in the right direction, but ultimately, biodiversity offsetting is doomed due to the non-fungibility of biodiversity.
The ‘Campaign for Nature’ emphasizes that governments must recognize biodiversity as a public good, akin to law enforcement or defence. Public goods must be funded by governments or incorporated into private investment decision-making through public policy regulations and incentives.
Construction’s Total Impact on Nature
Finally, does the Biodiversity Net Gain legislation address construction’s total impact on nature? Amanda Williams, the head of environmental sustainability at the Chartered Institute of Building, pointed out that it “excludes the production and processing of construction materials such as timber and sand and minerals, including gravel, iron ore, and rocks, and how they affect biodiversity.” This aspect will need to be addressed over time.
