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Climate Change, A Global Concern for all Aviation Stakeholders

Apr 29, 2021Airports, Climate Change, Emissions

“Aviation’s CO₂ emissions are projected to keep growing in the long term. There is an urgent need for all stakeholders to take action”. 

In the past decade, the impact of climate change on our world has become a subject of global concern. The global aviation industry produces around 2% of all human-induced carbon dioxide (CO₂) emissions, representing around 11% of CO₂ emissions from transport worldwide. In 2015, ICAO had forecast an annual growth rate for air traffic of around 4.6% until 2025, but the COVID-19 crisis had other plans. Despite this severe reversal of air traffic growth being experienced at the moment, a return to previously projected growth is expected in the medium term.

Though airports are seen as being the main stakeholders in this aspect, they also play an important role is driving collaboration between all operational stakeholders, in reducing the sector’s carbon footprint.

Unfortunately there is currently no airport in any country that is required by law to achieve carbon neutrality. On the positive side, certain airport operators in different parts of the world have been gradually channeling their efforts to reduce their CO₂ emissions, through an independent programme called Airport Carbon Accreditation (ACA). While other airports have chosen to directly offset their emissions through their Corporate Social Responsibility or Sustainability programmes.

With all the different strategies to mitigate these emissions, some airports would ask, if they wish to progress to becoming carbon neutral, what is the most effective way to identify and manage carbon emissions? The answer would be to participate in a globally recognised carbon management programme for airports that independently assesses and recognises airports’ efforts to manage and reduce their CO₂ emissions such as the already mentioned ACA program. Through this program Greenhouse Gas (GHG) emissions are managed and identified by three different scopes, namely Scope 1, 2 and 3, as categorised by World Resources Institute (WRI).

It is important for airports to be aware of the 3 different scopes of emissions present within its boundaries because this will assist in the recognition of emission sources (identify ownership), control of emissions sources and thus responsibility for managing the emissions. Each of these scopes of emissions should be reported by an airport; first the total emissions of scopes 1 & 2 and then separately the scope 3 since they are two different types of emission factor, market and location based as this helps to avoid double counting of the same emissions.

Envisa has long experience in supporting airports in achieving the ACA certification and other carbon management programs all around the world. This is complemented by its extensive delivery of robust environmental impact assessments and participation in European R&D programmes in the aviation sector. 


Importance of Identifying the 3 Scopes

If we take a scenario of electricity consumed at the airport, it may come from many different power production sources such as, non-renewable generation from offsite, on-site renewable power generation and there are also cases of the airport re-selling this power to the tenants and many other scenarios. Such cases are what lead to categorizing GHG emissions into the 3 different scopes to avoid double counting of the same emissions. Hence, in managing carbon emissions, it is of great importance that an airport identifies that sources of emissions and the different emission boundaries within the airport.

In consistence with the emission identification by scope, the reporting of emissions should be done separately for each scope, as laid out in the Airport Carbon and Emissions Reporting Tool (ACERT) tool, recommended by Airports Council International (ACI), to calculate these three scopes of emissions. Sometimes an airport can calculate one or two scopes at the same time while following ACI accreditation guidelines. While other airports prefer to calculate an individual scope’s carbon footprint before accreditation, for example scope 3 emissions can be calculated in a separate project in preparation for ACA level 3 accreditation.

For constant control and management of emissions, it is best for airports to maintain the good practice of carbon management by beginning to participate in the ACA program for airports with no accreditation and for those accredited they can annually either upgrade their ACA level or renew their current ACA level.

Managing the 3 Different Scopes of Emissions

An airport has more influence on what is under its control, hence Scope 1 emissions are owned or controlled by the airport operator and can be managed easily by the airport. Once the footprint of these emissions is calculated, the airport controls the emissions by reducing or offsetting them. With respect to the emission source, the reduction measures for Scope 1 emissions can be, implementation of new on-site waste and wastewater management technologies, introduction of electric ground support equipment to replace fossil fuel vehicles, and many more. Reducing some emissions can be a challenge since not all sources of emissions have more efficient technology innovations present to date that can be used to replace the existing.

Scope 2 emissions defined as GHG emissions from the off-site generation of electricity (and heating or cooling) purchased by the airport operator, can be managed by the airport with some limitations. Reduction measures can be implemented and currently the most common is the implementation of solar power generation systems, to reduce the amount of power that the airport purchases from non- renewable off-site power generation source. Airports having renewable heating source such as geothermal, do not need any energy reduction measures as this source is considered emission free. Like for scope 1 emissions, some emission sources do not have enough efficient replacement options.

It is more challenging to manage Scope 3 emissions since they are emissions from airport-related activities from sources which are not owned or controlled by the airport operator. This shows that managing GHG emissions in an airport is not just about the airport, but there are other GHG emitting activities within the airport boundaries that are involved such as airport tenant, third parties and other stakeholders. Hence, to help reduce these emissions, third-party engagement methods have proven to be the most effective. These engagements with third parties serve to urge them to become more efficient, less polluting, and smarter in their choices.

For all the 3 scopes of emissions, after reducing all emissions via various methods, the remaining carbon footprint equivalent can by invested in responsible carbon offsetting projects. It is recommended to offset after knowing the carbon footprint of all 3 scopes within the airport, then after the airport can be considered carbon neutral. The ACI ACA has now two ACA levels, namely level 3+ (Neutrality) and Level 4+ (Transition) to guide airports offset their emissions by investing in globally recommended offsetting projects.

In most cases for an airport, when Scope 1 and 2 emissions are combined, they make a smaller proportion of emissions than scope 3 emissions alone. This is the reason why airports are encouraged to strive to reach ACA level 3 accreditation in order to have a full view of all the scopes present within their boundaries.

Benefits of Managing all 3 Scopes of Emissions

Among the benefits of managing carbon by scope, the data collection phase brings an engagement between the airport itself and the third parties.

Economically, airports can save their financial resources by purchasing off-site non-renewable generated power to on-site solar power generation. Or if the airport switches to more efficient energy sources such as electric cars, it will save the funds spent on offsetting their fossil fuels consumed by fossil fuel vehicles and many more examples.

Environmentally and socially, the amount of carbon emissions that an airport generates from all 3 scopes of emissions affects the quality of air – which is a danger to human health,  a major cause of climate change non – conducive environments for animals and plants. Hence carbon reduction and offsetting practices by an airport are of great benefit to our environment.

Other Carbon Management Related Projects

During the years of experience in Carbon Management projects, Envisa has been conducting detailed emission assessments in different airports and helped the airports in their carbon neutral process. Envisa can recommend the following services related to managing the 3 scopes of emissions in an airport:

  • Participation in ACA programs – voluntary approach which allows airports to obtain a label according to their level of accreditation, but above all, gives them recognition from their peers and the public.
  • GHG foot printing and identification of opportunities for reduction.
  • Local air quality modelling and impact mitigation – as the 3 scopes of emissions affect the quality of air at an airport.
  • Waste management – falling under scope 1 emissions this can be considered as an independent project.
  • Energy management and optimisation – a high percentage of all the 3 scopes emission comes from energy consumption or production sources, hence conducting an Energy management and optimisation project would be of great value to the airport.

Envisa experts will be delighted to provide any of these services for you and to make it in the most relevant way according to your platform. In addition to the mentioned services, we  help you collecting the required data, writing the mandatory documents, and facilitating meetings with your stakeholders by workshops.

Do not forget to learn more about our solutions to tackle environmental issues in the aviation sector, and you can also read about our previous work at airports.

Please, do not hesitate to contact us for any questions or remarks by email: towani.mtonga@env-isa.com, and follow our activities on our website and LinkedIn page.


About the author



Energy & Environment Engineer


Towani MTONGA is an Energy and Environment Engineer who holds a ME3, Masters of Sciences in Management and Engineering of Environment and Energy from the IMT Atlantique Nantes in France. She is a Junior Consultant at ENVISA, and her principal responsibilities include assisting with Airport Carbon Accreditation (ACA) Projects and performing airport noise assessments.