Getting a Greener Vocabulary

Ann Hennigan

February 16, 2022

Sustainability—Key Terms & Concepts

The sustainability conversation has brought up a whole new vocabulary. Here are definitions of a few of the terms to help clarify the discussion.

Greenhouse gas (GHG) emissions are considered to fall in one of three categories (“scopes”):

  • Scope 1 emissions are those that come directly from sources owned or controlled by an organization. Examples include emissions associated with direct use of vehicles, furnaces, boilers, etc.
  • Scope 2 emissions are indirect and come from the energy an organization buys (heat, cooling, electricity, steam)
  • Scope 3 emissions are those from activities outside an organization’s control or ownership but that are impacted indirectly by the organization’s value chain. Examples includes emissions generated by sources like the organization’s employees, suppliers, and all upstream and downstream “value chain emissions.”

The scopes are important because they help businesses identify where most of their emissions are generated, allowing them to focus improvement efforts to have the greatest impact. More information is available on the Environmental Protection Agency’s website at

Carbon Capture and Storage/Sequestration (CCS) is the process of capturing CO2 before it reaches the atmosphere, then transporting and storing it.

Carbon Capture Utilization/Usage and Storage (CCUS) is the process of capturing CO2 emissions from large sources like industrial plants and power stations, or from the atmosphere, and transporting it to either be reused or stored in deep subsurface formations (such as depleted gas and oil reservoirs) where it can be stored permanently

Embodied Carbon is the total amount of carbon arising from a building’s construction, to include extraction and refinement of raw materials, and the manufacturing, transport, installation, maintenance, and disposal of building materials.

Environmental Product Declaration (EPD®) is a report that documents a product’s measured environmental impact. EPDs are developed in accordance with ISO standards and guidelines, are valid for 5 years, and provide an independent, third-party assessment of a product’s impact on the environment. In construction, they are used by consumers, designers, architects, developers, engineers, and others to create more sustainable buildings. (See also Life Cycle Assessment)

Life Cycle Assessment (LCA) is an analysis of the environmental impact of a product throughout its entire life cycle—i.e., from extraction of raw material through manufacturing, distribution, transport, use, maintenance, and eventual disposal or recycling.