5. Set GHG Emission Reduction Goals

5.1 Set GHG Emission Goals

The primary purpose of a GHG emissions inventory is often to assess emissions so that airport operators can understand the activities that produce the emissions and plan ways to reduce them. GHG emission reduction goals articulate the airport’s ambition for reducing emissions. There are various types of emission reduction goals that airports can adopt, such as base year reduction, net zero emissions, carbon neutrality, and science-based targets. Other sustainability goals, such as those focused on increasing energy efficiency or renewable energy, achieving zero waste, or adopting sustainable transportation practices, can contribute to achieving GHG goals by helping to reduce emissions.

5.1.1 Setting GHG Emission Goals

Emission reduction goals vary in their ambition and the level of effort needed to achieve them. Beginning by developing a general understanding of the key components of a goal will help you ensure that your airport selects a goal that aligns with its ambition. The GHG Protocol Mitigation Goal Standard provides guidance for setting goals. To design a goal that can maximize emission reductions, measurability, and completeness, airport operators should consider the following:

• Define Goal Boundary: A goal boundary refers to the parameters within which a specific goal is to be achieved. Typically, a goal boundary should align with the inventory boundary (See Section 2. Set Inventory Boundaries), but you do have the option to set a goal for a subset of your inventory. For example, you can choose to set a goal boundary that includes only Scope 1 and 2 emissions. The goal boundary can significantly impact emission reduction strategies. As an example, a goal that is limited to Scope 1 and 2 emissions may focus on achieving airport operational efficiencies, while a goal that includes the value chain may focus improvements on airlines, tenants, and the supply chain.
• Define Goal Type: There are four main goal types: Base year emissions goal (reducing emissions relative to your base year emissions), fixed-level goal (reducing emissions to an absolute emissions level), base year intensity goal (reducing emissions intensity relative to your base year emissions intensity), and baseline scenario goal (reducing emissions relative to a projected emissions baseline scenario).
• Define Goal Timeframe: To define the goal timeframe, airport operators should select a base year and choose whether to adopt a single-year goal (reduce emissions by a single target year) or multi-year goal (reduce emissions over a target year period).
• Define Goal Level: The goal level should significantly reduce emissions below your airport’s business-as-usual emissions trajectory. Science-based goals should correspond to an emissions trajectory that is in line with the most recent climate science.

5.1.2 Types of GHG Emission Goals

A key consideration when setting a goal is to identify priorities relative to your specific airport context. Understanding airport stakeholder ambition and the costs, feasibility, and implementation cycle associated with emission reduction opportunities will help you tailor emission reduction goals to your airport. Alignment between stakeholder priorities and GHG reduction goals influences the ability to successfully implement emission reduction strategies. Airport operators should work closely with key stakeholders when selecting a goal type, keeping stakeholder priorities and applicability top-of-mind.

Common GHG reduction goal types include:

• Base Year Reduction: Base year reduction goals aim to reduce emissions relative to the base year. They are often based on an absolute emission reduction by a target year relative to the base year and expressed as a percent reduction. Base year reduction goals are also sometimes expressed on an intensity basis (e.g., GHGs per employee). As an example, “Reduce 2020 base year emissions by 25% by 2030.”
• Carbon Neutral: Carbon neutral goals balance the amount of GHGs emitted with an equivalent amount of GHGs avoided or removed using carbon offsets. Goals should specify the goal boundary and are expressed as a fixed-level goal—as an example, “Achieve carbon neutrality in airport operations by 2030.”

• Net Zero: Net zero goals require reducing emissions to as close to zero as possible before offsetting residual emissions using emission removal offsets, resulting in no net increase in atmospheric concentration of GHGs. Net zero goals should specify a goal boundary and target year by which the airport will achieve net zero. As an example, in 2021, Airports Council International established a goal to achieve net zero Scope 1 and 2 emissions for global member airports by 2050. The Science Based Targets Initiative (SBTi) provides more specific corporate guidance for setting net zero goals in its Corporate Net-Zero Standard.
• Science-Based Targets: Science-based targets are aligned with the scientific consensus of limiting global warming to 1.5°C above pre-industrial levels. Typically, organizations set both near- and long-term targets relative to a base year. Near-term targets range between 5 and 10 years while long-term targets extend beyond that. An example, near-term science-based target is to, “Reduce 2020 absolute Scope 1 and 2 GHG emissions by 65% by 2030.” SBTi has guidance for several aviation-related sectors including passenger and cargo aviation (Science-Based Target Setting for the Aviation Sector). This sector-specific aviation guidance focuses exclusively on jet fuel emissions and is geared toward airlines, as jet fuel combustion represents more than 90% of most airline’s value chain emissions. Non-jet fuel-related emissions (e.g., airport operations) are not included and specific guidance is not yet provided. Please refer to the SBTi sector-specific guidance on Air Transportation - Airport Services upon publication.

Measuring progress over time is vital to ensure that your airport is on track to meet its GHG reduction goals. Airport operators should regularly assess and report on progress against goals. Sharing data-driven progress can ensure that stakeholders are engaged, held accountable, and motivated to collaborate closely across teams to achieve targets. Furthermore, tracking progress helps highlight additional reductions needed, guides resource allocation, and assesses effectiveness of current strategies.