There are fundamental differences in how climate change impacts airports. Airports are operationally different from, say, power stations or seaports. For example power stations are intrinsically enclosed facilities; their encasement against external elements is relatively straightforward. With seaports, appropriate walls or physical barriers can be erected to shelter against potential increases in rough seas or in sea-levels.
For airports, it is not possible to simply build physical barriers to close them off against adverse atmospheric effects that may afflict flight operations.
Airports are fixed assets with long operational life-cycles. They are also location-specific and consist of an operationally demanding complex of interdependent facilities. Their preset attributes are difficult to change or upgrade. Relocating them is difficult as the process of finding suitable airport sites is tedious. Upgrades during their operational life-time can be accommodated but are generally limited by local planning parameters and the state of prevailing technology. This is especially true in the case of an airport's overall runway alignment and airside configuration.
Mitigating the impact of climate change at airports therefore requires a different approach.
In the context of this article, several assumptions are necessary. These are that:
Climate change is given to mean changes in long-term weather patterns and their further consequence to atmospheric conditions. Therefore climate change needs to be seen as synonymous with long-term changes in atmospheric conditions. These are the elements deemed directly relevant to sustain flight operations.
There is robust scientific basis and irrefutable proof that climate change is significant and tangible. Also that such proof and/or basis is politically neutral and overrides value judgments.
It is presently assumed that climate change can/will impact on atmospheric conditions, to the extent that it leads to possible flight disruptions at airports. Related issues such as flooding, disruptions to airport access and so on are excluded from consideration.
Recognition that frequent and sustained disruptions to flight operations can cause consequential damages/losses to the airport from reduced asset utilisation; that they suffer from poor capital allocationand face increased exposure to potential claims from customer airlines and other third parties.
What Climate Change Means to Airports 
The medium that sustains flight is ‘air’ in the free atmosphere. This in turn means that elements influencing atmospheric conditions – for example wind, air temperature, barometric pressure, visibility, and so on – have a collective impact on the ability of an aircraft to remain safely aloft. This factor implicitly makes both aircraft and airports highly sensitive to changes in atmospheric conditions within their immediate vicinity.
Sensitivity to Meteorological Conditions
Meteorological elements such as visibility/precipitation, cloud base and density, barometric pressure, wind velocity, and so on combine in various ways to create storms and air turbulence. Their severity can cause conditions to go beyond the permissible operational envelopes for both aircraft and airports - thus disrupting conditions for the safe conduct of normal flights.
Within the immediate vicinity of an airport, an aircraft on approach to land or in a climb-out after take-off is typically at low altitude. At low altitudes, the margin for manoeuvring an aircraft is narrower than usual, simply because it is much closer to the ground and faces progressively constricted three-dimensional space in which to operate.
Primarily for this reason, take-offs and landings are deemed the most critical phases of flight. It is also in these phases of flight that adverse weather can impose its worst effects and limit safe flight operations. In adverse weather, when runway use is inadvisable, an approaching aircraft typically diverts to another airport, and take-offs are usually delayed. In such situations, an airport is technically ‘shut down.’
Vulnerabilities and Disruptions to Flight Operations
The operational nature of airports disallows the possibility of building physical barriers to protect an airport against poor weather. In the context of climate change the question is what would happen if long-term weather pattern changes significantly, resulting in frequent atmospheric disturbances and regular closures of airports?
Such disruptions would jeopardize the usefulness of any airport, and undermine asset utility. Frequent disruptions to flight operations also result in an airport suffering loss of income; airlines, its primary customer will incur unwanted costs and unfulfilled passenger expectations. These can bring knock-on consequences including vulnerabilities to litigation and claims for liquidated damages. These are amongst the key potential climate change risks for airports.
An Airport’s Runway as a Case in Point
An airport is an integrated complex with numerous functions and sub-functions. The vulnerabilities brought by climate change surrounding airports are therefore both broad and deep.
For simplicity, focus is narrowed down to the effects of climate change on a vital single airport element most affected by long-term changes to meteorological conditions – the runway.
An airport’s runway (or its system of runways) is the aircraft’s sole interface between air and ground. An aircraft’s ability to take-off and land depends on the runway’s physical characteristics and prevailing weather conditions. Unfavorable long-term meteorological conditions and the utility of a runway and consequential disruptions.
An airport’s runway system represents a significant cost and land use item in proportion to the whole facility. It is also a central enabling component in airport operations. Therefore if climate change frequently disrupts runway usability, the fundamental utility of the entire airport (and the value of its investment) is compromised.
For this reason and in the context of this article, any reference to 'airports' is considered interchangeable and synonymous with its runway and runway system.
As a general guideline, when weather considerations are taken into account, an airport (or more precisely its runway in this case) needs to be usable 95% of the time. If the incidence of adverse weather and usage of its runway falls to below 95%, its usability as an airport is deemed to be compromised (see ICAO Annex 3). Usability parameters are routinely described as “weather minima” and are specific to a particular airport.
Therefore safeguarding runway usability becomes a central consideration when addressing atmospheric conditions at airports and climate change. The mitigation of disruptions at this level is the fundamental impetus for addressing potential climate change vulnerabilities at airports. Changes to long-term weather patterns and their impact on atmospheric conditions may consequently affect airport development as follows:
Decisions on the location of future greenfield airports
The alignment and configuration of new runways
Continued usability (and upgrade options) of existing runways
Future investment suitability at an existing airport
Adoption and suitability of new technologies deployed/developed
Climate Change Impacts and Climate Resistance Measures
The focus on runways is seen as a precursor to understanding climate change impacts in the context of airports. It offers a basis for guiding climate resistance measures.
Assuming climate change is real and tangible, future guidance on airport development and planning should include addressing climate change impacts. This in turn should make climate resistance measures an integral part of all existing planning and design, as well as operational considerations. Equally important, appropriate scoping and specifications should follow suit.
Proper consideration of climate change and the implementation of climate resistance measures should help ensure asset and operational sustainability at airports. This approach promotes the most effective utilisation of airport asset and the efficient deployment of resources.
Climate Resistance Measures - The Way Forward
Please look out for my next blog post where I will discuss climate resistance measures and their implications. In the meantime, I would be glad to have your comments and/or suggestions below.
Footnotes:Limitations: All information presently expressed in this blog post is based on empirical knowledge and on known/standard industry references. It is impossible to dwell into the operating premise encompassing the entire airport/aviation complexion within the scope of this discourse. Technical detail, precision and/or correctness are presently skimped in favour of throwing up general and outline concepts for consideration. They are offered in good faith and as general guidelines only. Information expressed herein is therefore superficial and/or are incomplete in their articulation. In this, I wish to apologise in advance for my limited knowledge (and ignorance) in climate change issues and for the shortfalls this post invariably contains. It is therefore advised that all information extracted from this post should be appropriately validated prior to use. Notwithstanding, I hope the blog post holds sufficient content to spur interest and instil meaningful discourse towards tangible resolution.Whilst there may be different categories of airports, for simplicity, airports referred to in this post are facilities that typically receive-and-turnaround normal commercial passengers/cargo carrying aircraft.
Graphic: by author