Biodiversity

Airports can negatively impact biodiversity in several ways. Some of these impacts – such as controlling or deterring birdlife around airports for operational reasons – are direct and intentional. However, other impacts can occur through the loss or degradation of habitats when airports and airfields expand, and through the effects of light and noise pollution on many species. 

With over 2000 bird strikes – collisions between birds and aircraft – recorded annually in the UK, bird populations are treated as hazards around airports and are controlled accordingly. However, caution about bird populations extends well beyond the immediate vicinity of an airport – the CAA advises that steps should be considered to minimise bird populations as far as 10 miles away. 

Reducing the attractiveness of surrounding areas to large birds – for example by removing trees or other nesting habitat, or using noise and flare guns – can impinge on other wildlife populations. 

In addition, the law allows Natural England to issue licences to airports to control a range of bird species within an area 13 kilometres from the airport boundary, by shooting them, or by destroying nests or eggs – activities that are normally prohibited. The range of species that can be controlled in this way includes some threatened species, such as curlews and herring gulls, if an airport perceives that there is a safety issue.

Between 2020 and 2023, 30,773 birds were shot, 740 chicks destroyed, 5971 eggs destroyed, and 1806 nests destroyed under licence.

AEF acknowledges that maintaining safety at airports is crucial. However, in the public and nature conservation interest, we are calling for greater transparency about the fatal control of bird populations around airports and the way that licences are monitored. To obtain the figures above, it was necessary to submit Freedom of Information requests to Natural England.

Biodiversity matters because it supports the vital benefits humans get from the natural environment. It contributes to the economy, health and well-being, and it enriches our lives. 

UK Biodiversity Indicators, 2024

Other harm to wildlife can occur less intentionally. Birds, amphibians, invertebrates, fish, mammals and reptiles can be very sensitive to noise and light pollution. Studies have shown that even low levels of human noise disturbance can severely impact the ability of animals to communicate and breed. 

Light pollution (for example, from car parks, terminals or aircraft navigation aids)  harms biodiversity by interfering with natural day-night rhythms and night habits, affecting the reproduction, feeding, and migration cycles of many different animal groups. Artificial lighting can confuse migratory birds, depleting their energy sources and threatening their survival rates. It can delay or even prevent bats from leaving their roosts, or deter them from returning. By extending the hunting time of daytime feeders, light pollution can also lead to over-predation of some nocturnal species. When combined, noise and light pollution – from roads, shipping, urban sprawl as well as from aviation – can throw the lives of animal populations worryingly out of balance.

Two useful, open access research papers on the impacts of artificial noise and light pollution on biodiversity are here and here. 

Airport operations can also impact water courses due to water run-off from their runways, taxiways and other hard-standings that becomes contaminated with pollutants contained in de-icers, fire extinguishing products and fuel spills or leakages. In 2024, multiple criminal charges were brought against East Midlands Airport by the Environment Agency for de-icer entering the river system surrounding the airport – in breach of the airport’s water-discharge permits. Depleting oxygen in the river systems, the chronic water pollution encouraged a proliferation of fungus that thrives in such conditions and was harmful to fish and other aquatic life.

In a wider context, climate change resulting from carbon and non-CO₂ emissions from aviation (and other human sources) poses a serious threat to wildlife around the world. Rising global temperatures are warming oceans (impacting marine organisms), melting Arctic sea ice (destroying habitats), and increasing the risk of fires and drought that devastate wildlife.

“In Australia at the end of 2019 and start of 2020, 97,000km² of forest and surrounding habitats were destroyed by intense fires that are now known to have been made worse by climate change.”

The Royal Society

In the UK, carbon is  covered by national and international policies, although there are no policies addressing non-CO₂ effects. However, localised biodiversity impacts are usually addressed in the context of airport planning applications and environmental assessments. In some cases, the significance of likely biodiversity impacts has delayed airport expansion applications. As an example, planning permission for a development at Lydd Airport in the 1990s was delayed while investigations took place into the impact of aircraft noise on the breeding success of birds at the adjacent internationally protected wetlands.

The Environment Act (2021), which aims to strengthen biodiversity protections with the planning system in England, made biodiversity net gain (BNG) a condition of planning permissions and development consents in England. The new measures were launched by the Department for Environment, Food & Rural Affairs in February 2024. BNG can be on site, offsite or via purchasing biodiversity credits. Developers must be able to show that proposals will achieve a 10% net increase in biodiversity against a baseline (using a net gain toolkit). 

However, net gain effectively trades current losses in habitat area for promises of uncertain gains in habitat quality in the future (newly created habitats can take 30 years to mature). Questions have been raised about how net gain, which places new and significant burdens on local planning authorities (LPAs), will be monitored and regulated. In its report published in May 2024, the National Audit Office (NAO) stated that insufficient LPA access to ecologists capable of assessing developer plans, together with a lack of adequate BNG training, guidance and resources for LPAs, are key risks to the effectiveness of BNG implementation. Other key risks identified in the report include:

• the inability of Defra to respond adequately if elements of the policy don’t work as expected since it retains no oversight of the statutory BNG system;

• the private nature market not scaling up sufficiently to meet demand for off-site biodiversity units, which could lead to an over-reliance on statutory biodiversity credits (meant to be a last resort);

• Defra and Natural England’s inability to monitor progress and evaluate the impact of statutory BNG, which is limited by 1) information that is not available as expected, is incomplete or is inaccessible 2) delays in accessing information 3) the lack of a standardised, national approach to verifying and recording biodiversity gains.

According to the report, Defra acknowledges that until data and regulatory gaps are closed, the BNG system is vulnerable to being gamed. (The NAO’s full and summary reports can be found here).

Meanwhile, airport expansion plans risk harm to highly sensitive wildlife sites. Luton Airport, for example, has applied to increase its passenger numbers from 18 million to 32 million per year. The application threatens the destruction of Wigmore Valley Park, 70 acres of land that includes mature wildlife areas.

The Oglet Shore on the River Mersey is a RAMSAR site and a designated Site of Special Scientific Interest, but it is also adjacent to Liverpool John Lennon Airport which is planning to expand. Local people fear that the airport’s ambitions for growth will cause considerable harm to Oglet Shore’s ecosystem, and there is little confidence that the planning system will afford the site the necessary protections. 

Some airports, such as Heathrow and Gatwick, are keen to promote their biodiversity projects located in wildlife areas around the airports. However, in the context of noise and light pollution from commercial aircraft operations, the effectiveness of these projects in helping to halt the decline of biodiversity in the UK, or even locally, is far from clear. 

AEF is not persuaded that the Government can reconcile its continued support for environmentally damaging airport expansion with it ambitions to improve and enhance the natural world in areas surrounding airports.

Adopting a siloed approach to reversing biodiversity has been ineffective. As the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) concluded in its June 2021 report: 

Biodiversity loss and climate change are both driven by human economic activities and mutually reinforce each other”

Tackling Biodiversity & Climate Crises Together and
Their Combined Social Impacts, IPBES, 2021

This being the case, both of these environmental impacts must be tackled simultaneously – and urgently.