Aviation’s Impact on 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 aims to strengthen biodiversity protections within the planning system in England by making biodiversity net gain (BNG) a condition of planning permissions and development consents (Wales, Northern Ireland and Scotland have their own, devolved rules). 

The new measures were launched by the Department for Environment, Food & Rural Affairs in February 2024. They introduced the concept of the biodiversity unit, a standardised way of assessing the ecological importance of wildlife habitats that’s used to track losses and gains associated with a particular development. Developers should avoid or reduce negative impacts on biodiversity. In addition to achieving no net loss in this way, they must also show that a project will result in a 10% net increase in biodiversity against a baseline (using a net gain toolkit).

There are three options for delivering BNG: (1) on site; (2) off site (the developer achieves the 10% gain on their own land elsewhere, or finds a landowner or habitat provider selling biodiversity units); (3) through the purchase of statutory biodiversity credits (which the Government uses to invest in habitat creation in England). These three options can be combined, but the steps should be followed in order. BNG operates alongside the planning system’s mitigation hierarchy: avoid → minimise → restore/mitigate → compensate (as a last resort), and is meant to ensure that biodiversity is left in a measurably better state after development than before. (A Government explainer can be found here).

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).

The Environment Act’s (EA’s) best intentions have been further undermined recently. Section 20 of the EA states that, when new Bills containing environmental law are introduced, they must include “a statement to the effect that in the Minister’s view the Bill will not have the effect of reducing the level of environmental protection provided for by any existing environmental law.”

At the end of 2024 the Government introduced the highly controversial Planning and Infrastructure Bill with the aim of removing supposed environmental barriers to development-led growth. Attempting to show adherence to Section 20 of the EA, the Bill contained the following statement from the relevant Minister: “In my view … the Bill will not have the effect of reducing the level of environmental protection provided for by any existing environmental law.” Many nature experts, lawyers, nature trusts and NGOs strongly disagreed, with some arguing that Part 3 of the Bill amounted to giving developers the right to pay cash to trash nature.

Part 3 of the Bill introduced a strategic approach to biodiversity enhancement, rather than the existing site-by-site approach. Where Natural England identifies areas where multiple developments are likely and where existing nature protections might be an on-site issue, the environmental impacts of a project would be addressed through Environmental Delivery Plans (EDPs). Within an EDP, developers would no longer have to comply with elements of existing regulations and legislation (for example, the Habitats Regulations 2017 and the Wildlife and Countryside Act 1981). Instead, they would be able to pay into a new Nature Restoration Fund (NRF). Natural England would be responsible for using the fund to deliver strategic compensation and nature recovery within the whole EDP area to meet an Overall Improvement Test.

Effectively, the EDP approach and the associated levy turns the mitigation hierarchy within the planning system on its head. Compensation for environmental harm within an EDP becomes the first option, rather than a last resort.

After some amendments were made, the Bill became an Act in December 2025. The OEP – having previously raised doubts about Part 3 of the Bill – continued to express concern that the new measures “would, in some respects, lower environmental protection on the face of the law”, despite the Government’s assurances that it complied with S.20 of the Environment Act.

EDPs are currently limited to areas where nutrient neutrality in protected water environments should be maintained and where legally protected species are a legal or regulatory onsite issue. However, the expectation is that a wider range of environmental obligations will be covered in future. BNG policy supposedly remains the default system for the time being, even within an EDP. But because the PIA 2025 is intended to provide an alternative route to discharging existing environmental obligations, it is possible that BNG could be replaced by, or simply absorbed into, the EDP system. While the focus of the 2025 PIA was removing supposed environmental barriers to house-building, all proposed developments covered by an EDP area will fall within the new system, including airport expansion plans.

Meanwhile, airport expansion plans risk harm to highly sensitive wildlife sites. Luton Airport, for example has gained Governmental consent to increase its passenger numbers from 18 million to 32 million per year. The project threatens the destruction of Wigmore Valley Park, 70 acres of land that includes mature wildlife areas. Campaigners challenging the Government’s decision in the courts.

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.