Climate resilient airports

Airports are often classified as national critical infrastructure because they play an essential role for both mobility and economic growth. However, due to their fixed infrastructures and high vulnerability to disruptive weather events, they are particularly vulnerable to the potential consequences of climate change, which can create both operational and commercial impacts.

Climate change threatens the continuity of air-freight operations, potentially leading to disruptions that increase costs for the whole supply chain. Adapting airport infrastructure and services is a key measure to ensure operational continuity for business and industry, affecting several economic activities. Strengthening airport resilience is particularly critical to maintaining connectivity, especially in tourism-dependent regions, thereby supporting economic development.

Airport resilience can be defined as the ability of operations and infrastructure to withstand and recover from external disturbances caused by current climate variability and future climate change. Those include slow onset events and effects of increased frequency and intensity of extreme events. These effects on airports are expected to occur at varying timescales and can be either intermittent or persistent. Impacts such as sea level rise and temperature increase will be experienced persistently but gradually, allowing longer-term planning. However, intermittent disruptive weather impacts such as heavy precipitation events or convective weather are projected to happen with an increased frequency and/or intensity due to climate change, therefore requiring measures which can be applied proactively according to the situation.

Building resilience to climate change while coping with significant traffic growth is a double challenge. Therefore, these two issues should not be dealt with in isolation, but in parallel. In particular, it is important to note that developing climate change resilience as part of on-going operational and infrastructure improvements can be the most efficient and cost-effective way to achieve this. In case of airport enlargement to accommodate a greater number of passengers and flights, climate resilience aspects should be considered and implemented as an integral part of the work.

Burbidge (2016; 2018) provides a detailed overview of the main climate change risks affecting European aviation, their impacts on infrastructure and operation of airports and identified possible adaptation measures enabling to cope with climate-change induced challenges. In 2022, ICAO (International Civil Aviation Organization) developed a Menu of adaptation options for aviation’s stakeholders. It includes measures for adapting airports, for making Air Navigation Service Providers (ANSP) more capable of managing risks, and for improving  operational procedures.

Adaptation options apply to both infrastructure and operations. They address possible changes in rain and snowfall precipitation, temperature, wind, and sea level rise.

Heavy precipitation

Events of extreme precipitation are likely to become more frequent according to climate scenarios. Heavy rain may impact airport throughput by requiring a greater distance between aircrafts. In addition, the existing drainage capacity of aerodrome surface may not be sufficient to deal with more frequent and intense precipitation events. Those can lead to an increased risk of runway and taxiway flooding. Underground infrastructure, such as electrical equipment, may also be threatened by heavy rain inundation.

• Possible adaptation measures should be aimed at improving the capacity and coverage of the drainage system and, in parallel, at increasing water resistance of underground infrastructure (e.g. waterproofing of electrical cables). Water management solutions include the replacement of concrete/asphalt with soil/vegetation and the improvement of storm water management facilities to reduce flooding, minimize erosion and improve water quality.

Average rain precipitation

Decrease in annual average precipitation is expected in some regions, in particular in Mediterranean. Insufficient precipitation may lead to lack of water and water restrictions which can impact both operations and infrastructure of airports. Desertification may cause sand damage of airframes and engine, encroachment of sand dunes to runways and apron may be experienced affecting operation of the airport.

• Amongst the suitable measures to be implemented are a new water management strategy focused on water saving, reusing of water and storing of rainwater and structural measures protecting runways from sand encroachment.

Temperature

Increase of annual and daily maximum temperature is expected along with heatwaves, which are likely to become more intense and persistent. Risks for airport infrastructure include heat damage to tarmac surfaces of runways and apron in terms of deformation, with consequences on carrying capacity and durability. Increased summer cooling of airport buildings will also be needed; some buildings may experience overheating leading to health issues for passengers and for the staff. Risks of extreme temperature for operations include reduction of aircraft engine thrust which in turn affects runway length requirements for take-offs.

• Measures aimed at increasing the resilience to temperature rise can be divided into measures on airport buildings and equipment (air-conditioning, better insulation, development of green infrastructure) and measures on aerial infrastructure (new tarmac materials resistant to heat, extension of the runway, better equipment cooling).

Winds and storms

Wind directions are expected to change more frequently and rapidly, increased deviation from the prevailing wind direction may cause runways to experience more cross-winds. As far as the aerial infrastructure is concerned, damage caused by strong wind may occur and building up a new crosswind runway may appear essential to increase resilience of operations.

Projections regarding the frequency, location and intensity of storms in Europe are uncertain. However, many studies project that, in the longer term, the overall number of storms will decrease while the strongest storms will be more intense (particularly in Northern and Western Europe). Due to temperature rise and increased insolation higher convection intensity is expected causing disruption to operations, route extensions and associated delays. Larger, meso-scale convective systems may even have potential to affect several airports in the region.

• There are various adaptation measures to be considered to increase airports resilience against extreme weather, including wind-proofing of aerial infrastructure, securing assets prior to storm events and re-routing of aircrafts. The improvement of early warning systems and emergency management plans is fundamental to address storms.

Sea level rise

Sea level rise may lead to permanent inundation at costal airports and capacity loss unless preventive measures, such as constructing sea defences, are taken. In the longer term, the potential permanent capacity loss at some locations could have an impact on overall network capacity and operations. The impacts of higher occurrence of storm surges may be experienced in the shorter term and may result in a temporary reduction of capacity and increased delays.

• Adaptation measures include constructing or reinforcing sea defences, also including coastal vegetation, raising infrastructure and enhancing water management. Relocating vulnerable infrastructure to areas less impacted by marine flooding is also an option.

Snowfall

Despite the fact that snowfall is generally expected to decrease, there may be an increase in heavy snowfall days, or snowfall in new areas. It means that some geographical area needs to be prepared for heavy winter weather. In those cases, the airport´s winter maintenance capacity must be improved.

• Developing a plan for adequate snow and ice removal and acquiring the needed equipment might be necessary. As an example, the Munich Airport has a winter service to ensure safe operations also in harsh conditions.

Finally migratory birds are a challenge at airports in many regions due to their potential effects on aircraft operations, particularly large birds such as geese, eagles, and pelicans. Changing species and migration patterns due to climate change could affect aircraft operations and increase the potential for bird strikes (ICAO, 2018).

The overview above highlights the wide variability of potential climate change impacts on European airports. Those might affect a very diverse range of infrastructures and operations, as well as their strong local specificity. Therefore, actions aiming to improve airport adaptation capacity (i.e. understanding the problems, assessing the problems, selecting and implementing adaption measures, communication and airport stakeholders’ engagement) need location-specific approaches.

The main stakeholders involved in the process aiming at increasing climate change resilience of airports are airport operators, aircraft operators (airlines), air navigation system providers and engineering and construction companies providing implementation of the adaptation measures. These stakeholders are supported by research and consulting companies providing risk and vulnerability assessment, climate projections, weather forecast and strategic planning services.

In 2023 EASA (the European Union Aviation Safety Agency) started the European Network on Impact of Climate Change on Aviation (EN-ICCA), a large network of experts from the aviation industry, national aviation authorities, research organisations and national meteorological services. It aims to help both aviation stakeholders to get better prepared for the effects of climate change and scientists to identify research priorities for the aviation sector.

Success factors for initiating, drafting and implementing climate change adaptation plans of airports include the availability of sufficient information, effective involvement and cooperation of relevant stakeholders, sufficient financial resources and policy support.

Adjusting operational procedures are generally considered cost-effective. These measures are classified as “low-regrets”, “no-regrets” and “win-win” measures. Other cost-effective measures include so-called “soft” measures such as training of airport staff and sharing of best practices with other airports in the region.

Conversely, possible trade-offs of certain adaptation measures require careful consideration to avoid maladaptation. For example, airports may start to experience crosswinds but have no crosswind runway. This may entail the need for a new runway causing the change in procedures and airspace redesign. In turn, this may incur an additional environmental risk due to the redistribution of noise impact around airports.

The cost of implementing construction and operation measures at airports varies significantly according to the specific measure, airport size, climate region and climate challenges addressed. Basically, the measures building resilience of existing infrastructure, e.g. wind-proofing of aerial equipment are less expensive in comparison with newly built infrastructure, e.g. a new runway addressing higher occurrence of cross-wind.

Win-win measures have the greatest benefit. Those address both the development issues of the airport (due to the gradual growth of air traffic) and, at the same time, their climate change resilience. As far as implementation of these measures is concerned, there would be no conflict between promoting the economic interests of the airport and implementing measures adapting the airport to climate change, which, if implemented separately, could significantly affect the airport's economy. Therefore, the motivation of stakeholders is higher, and it is easier to allocate financial resources for these projects. In general, airports are important economic hubs, both in terms of the business generated by airport passengers and of air freight transport of goods. Adaptation actions ensuring the availability of reliable airport infrastructure is crucial for these economic activities. It is particularly important for urgent transport activities, such as the timely delivery of biological material for transplants. Measures are typically funded by airport operating companies which can be supported by  public budgets or by means of European financial instruments.

While implementing the adaptation measures, the national and European policies dealing with the reduction of aircraft emissions and the transition to sustainable mobility must be taken into account. The EU smart and mobility strategy envisages a sustainable, smart and resilient transition of the transport sector, also including aviation. The strategy specifically encourages sustainable solutions to adapt the EU mobility system to climate change and make it resilient to disasters.

Moreover, the adaptation measures must comply with internationally established aviation standards and rules to ensure reliability and safety of air transport.

The Aviation Strategy for Europe recognizes the crucial role that aviation plays in promoting economic growth, job creation, trade and mobility in the EU, and emphasizes the importance of high safety standards for the competitiveness of the sector in the EU.

EASA and the Member States share responsibility for all domains of aviation safety. Since 2023, managing the impact of climate change is one of the strategic priorities of the European Plan for Aviation Safety (EPAS). The plan is developed by EASA in collaboration with EASA Member States and industry. It is mandated by the EASA Basic Regulation (EU) 2018/1139 and ensures consistency with the ICAO Global Aviation Safety Plan. Since 2024 the EPAS has included a research action to investigate the impacts of climate change on aviation.

Typical time needed for preparing and implementing the whole adaptation strategy for an airport is in the order of years, normally between 1-3 years. However, the implementation of individual measures may take only months if well prepared and carried out effectively. The crucial aspects of smooth implementation of adaptation strategy are efficient cooperation of stakeholders involved and sufficient financing sources available.

The lifetime of construction measures implemented at the airport is virtually unlimited if well maintained. The lifetime of operational measures is dependent on the allocation of institutional and personal resources, and the involvement and cooperation of stakeholders.