Environmental terms

STRzero is the name of the carbon strategy adopted by the state airport in Baden-Württemberg. The STRzero carbon strategy includes , amongst other things, the airport operator’s emissions reduction target.

The Energy and Climate Master Plan is an action plan that sets out the steps required for the state airport to comply with the Baden-Württemberg Climate Protection Act. It therefore forms the basis for STRzero. The Energy and Climate Master Planis updated regularly.

‘Scope’ refers to a sphere of influence. Stuttgart Airport calculates its carbon footprint in accordance with the Greenhouse Gas (GHG) Protocol. This internationally recognised protocol categorises all greenhouse gas emissions into three scopes, which help to systematically identify sources of emissions and reduce them in a targeted manner:

• Scope 1: These are direct emissions generated directly during processes and within the facilities of Stuttgart Airport. These include, for example, the combustion of fossil fuels such as natural gas or diesel, as well as refrigerant leaks from refrigeration or air-conditioning systems, and the application of de-icing agents.
• Scope 2: These emissions arise indirectly from the consumption of purchased energy, i.e. from the electricity procured by Flughafen Stuttgart Energie GmbH. The emissions therefore do not originate from the airport’s own operations, but from the generation of the energy itself.
• Scope 3: These are all other indirect emissionsarisingalong the upstream and downstreamvalue chain. These include upstream emissions, such as those from purchased goods and services,transportandlogistics, business travel or employees’ commutes. It also includes downstream emissions, for example from recycling processes, land-based transport of passengers, visitors or employees of companies based at the airport, as well as emissions from air travel. Stuttgart Airport has only very limited influence over Scope 3 emissions.

Airports Council International (ACI) is the European airport association based in Brussels. It represents over 600 airports in 55 countries. In June 2019, as part of the Net-Zero Initiative, its members committed to avoiding or reducing their directly controllable emissions by 2050 and to offsetting any remaining emissions through appropriate measures, without resorting to traditional offsetting schemes.

Emissions refer to the release of substances, usually in the form of gases or particles, into the environment. When it comes to the climate, the term ‘emissions’ refers to the release of greenhouse gases into the atmosphere.

Emissions can be categorised according to their source and composition:

• Greenhouse gas emissions:Theseinclude carbon dioxide (_CO₂), methane and nitrous oxide. They are produced primarily by the combustion of fossil fuels.
• Pollutant emissions: These include nitrogen oxides , particulate matter and sulphur dioxide.
• Noise emissions: These refer to noise from machinery, vehicles and traffic.
• Heatemissions:Waste heatgenerated, for example, by the combined heat and power plant at the airport.

Carbon dioxide (CO₂) is a gaseous compound consisting of carbon and oxygen. It occurs naturally in the atmosphere. If its concentration rises – for example, as a result of human activities – this intensifies the greenhouse effect, leading to global warming. CO₂ is produced, for example, during respiration and during the combustion of hydrocarbons such as petrol, natural gas or kerosene.

CO₂ emissions are produced when materials such as oil, coal or wood are burnt. This releases carbon dioxide, which accumulates in the atmosphere. Stuttgart Airport records not only CO₂ but also all other greenhouse gas emissions it causes. These are convertedinto CO₂ equivalents (_CO₂eq).

This means that the quantity of a greenhouse gas is converted into the equivalent amount of CO₂ that has the same impact on the climate.

Greenhouse gases are gases such as carbon dioxide, nitrogen oxides, hydrocarbons and methane. They occur both naturally and as a result of human activities. If their concentration rises, this leads to global warming. At the airport, these gases are produced primarily by the combustion of fuel in vehicle engines and aircraft engines.

Net greenhouse gas neutrality, or‘net zero’, means that a balance is achieved between greenhouse gas emissions and the removal of these gases from the atmosphere.

It is important to note that emissions should, first and foremost, be avoided or reduced. They may only be offset where this is not technically feasible – in other words, the same amount of carbon dioxide must be removed from the atmosphere as was emitted.

Stuttgart Airport is guided by the Baden-Württemberg Climate Protection Act, which sets a target of net greenhouse gas neutrality by 2040. For the airport operator, ‘net zero’ means, as a first step, reducing its Scope 1 and Scope 2 emissions as far as possible through appropriate measures. The company has developed the technical solutions for this in itsEnergy and Climate Master Plan.

The landing and take-off cycle, or LTO cycle for short, has been established as an international standard by the International Civil Aviation Organisation (ICAO). It is used to calculate local, traffic-related emissions. This refers to all aircraft movements below 3,000 feet (just under 1,000 metres) in the vicinity of the airport. The cycle is divided into the following phases: landing, taxiing, handling, re-taxiing, take-off and climb. Fuel consumption is determined for each phase in order to calculate the resulting greenhouse gas emissions.

The Auxiliary Power Unit (APU) is an auxiliary engine fitted to an aeroplane. When aeroplanes are on the ground and the main engines are switched off, the APU supplies the necessary power for the on-board electronics and the cabin air conditioning whilst passengers are boarding and disembarking. The APU also generates the compressed air required to start the main engines.

Guarantees of Origin (GOs) document the origin and quantity of electricity generated from renewable energy sources. They form the basis for energy suppliers’ electricity labelling, as suppliers may only market their electricity as coming from renewable sources if they can provide these Guarantees of Origin. The certificates are managed in the German Certificate of Origin Register maintained by the Federal Environment Agency.

A smart grid is an electricity network that not onlyreceives and distributes energy, but is also capable of communicating. It uses digital technologies to coordinate electricity generation, storage, consumption and grid operations. This is important because a large proportion of electricity isno longer generatedcentrally in power stations, but decentrally in wind and solar farms. A smart grid can detect in real time when too much or too little electricity is being fed into the grid or consumed. An intelligent control system balances out fluctuations by predicting bottlenecks and automatically taking countermeasures.

The German Sustainable Building Council (DGNB e. V.) has developed a certification system to make construction measurable and comparable. This system is available in various versions for different types of buildings. In the certification process, the three dimensions of sustainability (environmental, social and economic) are given equal weight in the assessment. In addition, the technical and procedural quality of the projects is assessed. The assessment criteria are tailored to different types of building use and can be applied to new builds, existing buildings, refurbishments and building operations.

Ultrafine particles are produced during combustion processes involving very high temperatures – for example, when smoking tobacco, from burning candles, or in engines such as aircraft engines. In the air around the airport, they occur as complex mixtures in varying concentrations.

TOC stands for Total Organic Carbon – it indicates the proportion of organic carbon in a sample. This can be used, for example, to determine the extent to which water is contaminated with foreign substances.

At the airport, de-icing agents are used on aircraft and runways in winter. These contain carbon, which is, however, readily biodegradable. The contaminated water is pre-treated in a fluidised-bed reactor with the aid of bacteria. It can then either be discharged to local sewage treatment works or – if suitable – discharged into surrounding water bodies. An online monitoring system checks whether the water quality is good enough: the TOC value must be below a certain threshold.

An aircraft movement is the take-off or landing of an aeroplane.

The sound pressure level measures the intensity of a sound event.

The continuous sound level helps to assess noises whose volume varies over a period of time or is interrupted by pauses. The individual sound level values are combined to form a comparative value. This value takes into account the intensity, duration and frequency of the individual sound events.

Aircraft noise reports

The noise protection zone describes the classification of the immediate surroundings of a commercial airport in accordance with the German Aircraft Noise Act. These are:

• Daytime Protection Zone 1: Continuous sound level from 65 dB(A)
• Daytime protection zone 2: Continuous sound level between 60 and 65 dB(A)
• Night-time protection zone: continuous sound level of 55 dB(A) or above and at least 6 peak levels exceeding 57 dB(A)