Next steps for nature: Implementing Biodiversity Net Gain

Mandating Biodiversity Net Gain can help maximise protection of the natural environment as we pursue economic growth, writes WSP's Associate Director for Ecology Hannah Bilston

$44 trillion – or half of the world’s total GDP – is directly dependent on nature. With its loss, our society faces an existential threat. This biodiversity emergency, twinned with the climate crisis, shows that nature recovery is no longer a “nice-to-have” but essential for thriving societies and communities.

Nature provides a wide range of benefits which can often be taken for granted and this has led to current challenges for nature where millions of plant, animal and insect species are in decline. There has been some success in halting this decline through the introduction of legislation which protects sites and specific species, but bolder action is required to reverse it.

Through the new Environment Act the UK Government will mandate Biodiversity Net Gain (BNG) in England from January 2024. This will significantly bolster protection of the natural environment to maximise its potential. It’s therefore vital that businesses and local authorities across England have the knowledge and tools they need to implement BNG and so it can be a positive tool to aid nature recovery.

BNG will not apply in other parts of the UK; however, to deliver an overall improvement in biodiversity, Scotland will be introducing a positive effects for biodiversity approach and Wales will introduce a net-benefits for biodiversity approach.

The value of biodiversity

Protecting biodiversity and maintaining diverse ecosystems enables us to better withstand and respond to environmental changes, while still delivering services that are essential to society, such as agriculture, food security, clean water and climate mitigation.

BNG was introduced, so that future development in England does not happen at the expense of the natural environment that we depend upon. From January 2024, most large, new developments in England will be legally required to deliver a minimum of 10% net gain of biodiversity on what was already there. This will help to ensure that projects not only replace nature lost but leave biodiversity in a better state than before.

Crucial to the delivery of BNG is implementation of the mitigation hierarchy. Best practice is to avoid impacts in the first instance through good design and then to mitigate for them before considering compensation - and as a last resort offsetting them. Onsite creation of wildlife rich habitats should be maximised and then if required the use of offsite offsets can be utilised. A Biodiversity Metric is used to enable the biodiversity losses and gains to be measured and quantified in a standardised way.  

Though BNG has faced criticism for increasing development costs, in the long-term it is hoped BNG will support economic growth, boost our habitats and species, and create a lasting impact on communities across England.

Local Planning Authorities will be critical to the success and impact of BNG and they need support and resources to help them in their role in overseeing the implementation and monitoring of BNG.  There is currently a significant requirement to increase the capacity and ecological expertise throughout planning teams in England so BNG can successfully deliver for nature and local communities.    

Positive signs

Last year, Lightsource bp commissioned WSP to undertake an independent audit of some of its existing operational solar sites to understand their current BNG value, ahead of the legal requirement.

WSP assessed ten ground mounted solar farms against industry biodiversity principles and metrics and identified positive habitat gains on the majority of sites. Overall, nine showed improved habitat gains with five achieving at least 10% BNG.

Of the five sites which did achieve BNG, one was identified as showing a positive habitat change of 280%, and another achieved over 115%, showing the potential for significant benefits to the natural environment through considered management and responsible development methodology.

Ultimately, we all have a duty to protect the natural world and the habitats we depend on. Restoring nature not only benefits the environment but having access to nature also improves health and wellbeing, and safeguarding biodiversity is also essential for the growth of towns and cities across the UK.

With BNG becoming mandatory in England in the New Year, we are moving a step closer towards a holistic approach to sustainable development which rightly places the protection of nature alongside economic growth.

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