Alcoa Sustainability Glossary

Biodiversity:

The variety of all life forms, the different plants, animals and microorganisms, the genes they contain and the ecosystems of which they form a part.

Carbon footprint:

The total amount of greenhouse gases (GHGs) caused directly or indirectly by an individual, organization, event, or product.

Circular economy/circularity:

An economic system that uses a systemic approach to maintain a circular flow of resources, by recovering, retaining or adding to their value (through processes such as recycling, reusing, repurposing, and refurbishment), while contributing to sustainable development. Circularity is the application of the circular economy principles within companies’ processes or products. These definitions are informed by ISO 59004:2024.

Climate change risk assessment:

An assessment of the likelihood of current and future climate hazards, including physical risks such as extreme heat or flooding, and transition risks such as regulatory changes, and their potential impacts to the environment and communities.

Climate-related physical risks:

Risks in the physical environment associated with impacts from climate change. These risks can be acute (event-driven) or chronic (associated with longer term shifts in climate patterns). Acute risks could include heat waves, floods, storms and fires. Chronic risks could include above-average temperatures that can lead to droughts and rising sea levels.

Climate-related transition risks:

Risks associated with the transition to a lower GHG future. Transition risk categories include policy and legal, technology, market, and reputation risks.

Energy intensity:

An indicator of how much energy is used per unit of activity or output. Alcoa’s intensity data represents the amount of energy we used onsite in the form of fuels or purchased electricity to produce alumina and aluminum.

Greenhouse gas (GHG) emissions/greenhouse gases:

Gases that trap and hold heat in the atmosphere, contributing to the greenhouse effect. These include carbon dioxide, nitrous oxide, methane, and fluorinated gases.

Low-carbon alumina

Alumina that is manufactured using activities and/or processes that generate lower levels of carbon dioxide equivalent (CO2e) emissions compared to conventional ones. In the context of the aluminum industry, low-carbon alumina is generally understood to be produced in a refinery portfolio with an average CO2e emissions intensity that is less than 0.6 metric tons of CO2e per metric ton of alumina produced, including both direct and indirect (Scope 1 and Scope 2) emissions from bauxite mining and alumina refining.

Low-carbon aluminum:

Aluminum that is manufactured using activities and/or processes that generate lower levels of CO2e emissions compared to conventional ones. In the context of the aluminum industry, low-carbon aluminum is generally understood to be produced with less than 4.0 metric tons of CO2e for every metric ton of metal, including both direct and indirect (Scope 1 and Scope 2) emissions from mining, refining, smelting and casting.

Materiality for Sustainability:

Materiality for sustainability, including sustainability reporting, as opposed to financial materiality, is the significance, positive or negative, of a sustainability topic or issue to a company's business and its stakeholders.

Net zero:

A state where the total emissions of greenhouse gases are reduced to as close to zero as possible and any residual emissions should be balanced with an equivalent amount of carbon dioxide removal measures, leaving zero in the atmosphere.

Recyclability:

The characteristics of materials that retain useful physical or chemical properties after serving their original purpose. These materials can be reused or remanufactured into additional products. This definition is informed by the European Environment Agency’s definition of recyclability.

Recycled content:

The portion of materials by mass-weight used in a product that have been diverted from the solid waste stream. These materials can have pre-consumer and/or post-consumer components, in accordance with the ISO 14021 standard:

• Pre-consumer: material diverted from the waste stream during a manufacturing process, excluding the reutilization of materials such as rework, regrind or scrap generated in a process and capable of being recovered/reclaimed within the same process that generated it.
• Post-consumer: material generated by households or by commercial, industrial and institutional facilities in their role as end users of the product which can no longer be used for its intended purpose.

Renewable energy:

Energy that is derived from natural processes that are replenished constantly, such as sunlight, wind, and hydropower.

Scope 1 GHG emissions:

Direct emissions generated by sources owned or controlled by a company or organization.

Scope 2 GHG emissions:

Emissions resulting from purchased electricity and other energy sources.

Scope 3 GHG emissions:

All other indirect emissions that occur upstream or downstream in an organization’s value chain.

Sustainability/sustainable:

At Alcoa, sustainability means operating in a way that seeks to minimize environmental impacts, prioritize safe work practices, and positively influence our employees, customers, and the communities in which we operate.

Waste recovery:

Diverting products and materials from the waste stream with the intent to repurpose them in place of materials which would otherwise have been used to fulfill a particular function. This includes reuse and recycling.

Disclaimer:

This Sustainability Glossary is provided for informational and reference purposes only. It defines selected terms as used in our sustainability-related reports and communications, including our annual Sustainability Report. These definitions are current as of the “Last Updated” date shown and may be revised from time to time.  This glossary is not incorporated by reference into any filing made with the U.S. Securities and Exchange Commission, unless expressly stated in such filing. We do not undertake to update this glossary on a fixed schedule, and readers are encouraged to consult the version applicable to the specific report or communication being referenced.

Neither the 2024 Sustainability Report nor this Glossary should be deemed to constitute an update or re-affirmation of the data contained therein as of any future date. Any future update will be provided only through a public disclosure indicating that fact.

(June 2025)