Carbon Dioxide Removal (CDR) Glossary of Terms
Atmospheric Carbon Capture
Capturing CO₂ directly from the air, typically through Direct Air Capture (DAC) technologies, to combat climate change.
Bioenergy with Carbon Capture and Storage (BECCS)
A technology that combines biomass energy production with carbon capture and storage, aiming to achieve net-negative emissions. See What is Direct Air Capture for a comparison of carbon dioxide removal methods.
Biomass Carbon Removal and Storage (BiCRS)
Processes that use biomass to capture atmospheric CO₂ and then store it, such as through biochar production, biomass burial, or combining biomass with carbon capture and storage (BECCS). It aims to achieve durable carbon removal while potentially providing additional environmental benefits.
Carbon Budget
The allowable amount of CO₂ emissions left to limit global warming to a specified target, such as the 1.5°C above pre-industrial levels set at the 2015 Paris Agreement.
Carbon Capture
The process of capturing CO₂ emissions from various sources, such as power plants or the atmosphere, to prevent their release into the atmosphere.
Carbon Capture Technology
Technologies designed to capture CO₂ emissions from various sources to reduce their presence in the atmosphere.
Carbon Capture, Utilization, and Storage (CCUS)
An approach to managing CO₂ emissions by capturing and then reusing or storing the CO₂ instead of releasing it into the atmosphere. Carbon Capture and Utilization (CCU) and Carbon Capture and Storage (CCS) are sometimes spoken about separately. CCS usually refers to capturing carbon from the source of emissions and not removing existing atmospheric CO₂. For more see: What is CO2 Utilization? and What is Carbon Sequestration?
Carbon Dioxide Removal (CDR)
The process of removing CO₂ from the atmosphere after which it is stored in geological formations or utilized for other purposes, e.g. sustainable aviation fuel. Direct Air Capture is one of the technologies used for CDR.
Carbon Footprint
The total amount of greenhouse gases, especially CO₂, emitted by an individual, company or activity, often measured in tonnes.
Carbon Markets
Systems where companies can trade carbon credits to offset their emissions. Carbon capture projects can generate such credits.
Carbon Neutrality
A state where CO₂ emissions are effectively zero, often achieved by balancing emissions with carbon offsetting and removal. See: Net-Zero
Carbon Negative / Negative Emissions
A scenario where more CO₂ is removed from the atmosphere than is emitted, often achieved through technologies like Direct Air Capture.
Carbon Offset
Actions or investments made to compensate for CO₂ emissions, typically through projects like reforestation or renewable energy.
Carbon Removal Credits
Credits earned by removing CO₂ from the atmosphere, which can be sold or traded as part of carbon offset initiatives.
Carbon Removal Technology
Technologies that capture and remove CO₂ from the atmosphere to reduce its concentration and mitigate climate change.
Carbon Sequestration
The long-term storage of carbon dioxide in underground geological formations, forests or other carbon sinks to prevent its release into the atmosphere.
Carbon Sink
Natural or artificial systems that absorb more carbon than they emit, helping reduce overall CO₂ levels. Examples include forests, oceans and algae ponds.
Climate Change Mitigation
Actions or technologies that aim to reduce greenhouse gas emissions or increase carbon sequestration to limit the effects of climate change.
Direct Air Capture (DAC)
Direct Air Capture (DAC) is a technology that captures CO₂ directly from the air, helping to reduce overall atmospheric CO₂ levels. DAC allows for carbon dioxide storage or reuse to fight climate change caused by CO₂ emissions. For more see: What is Direct Air Capture?
DAC Process
During the DAC process, CO₂ is removed from the atmosphere by drawing in air using large fans and capturing the CO₂ through chemical reactions with solid sorbents or liquid sorbents, after which the CO₂ is concentrated and stored securely, often underground, or it is reused in various processes. For more see: How Does Direct Air Capture Work?
Direct Air Capture Technology
The specific methods and tools used in capturing CO₂ directly from the atmosphere to reduce greenhouse gas concentrations. For more see: DAC Technologies
Geological Sequestration or Geological Storage
The process of storing CO₂ in underground rock formations to prevent it from re-entering the atmosphere, a common form of carbon sequestration. Mineralisation in geological carbon dioxide sequestration refers to the process where CO₂ reacts with minerals in rocks to form stable carbonates, locking the carbon away permanently. For more see: What is Carbon Sequestration?
Greenhouse Gases (GHGs)
Gases that trap heat in the Earth’s atmosphere, contributing to global warming. CO₂ is one of the primary GHGs targeted by DAC. Greenhouse Gas (GHG) removal is the removal of greenhouse gases, such as CO₂, from the atmosphere to mitigate climate change.
Hard-to-Abate Sectors
Industrial sectors that are challenging to decarbonise, such as cement, steel and aviation, often requiring advanced carbon capture or removal solutions. For more see: Hard to Abate Industries and the Decarbonisation Challenge
High Durability CDR
A high durability carbon dioxide removal refers to methods that capture and store CO₂ in a way that ensures it remains securely sequestered for a long period, typically over centuries to millennia. See: Permanent CO₂ Storage
How Does CO₂ Cause Climate Change?
CO₂ traps heat in the atmosphere, causing a greenhouse effect that leads to global warming and the subsequent climate change.
Life Cycle Assessment (LCA)
An assessment of the environmental impact of a product or process over its entire life cycle, which is crucial in understanding DAC’s benefits. For more see: The Advantages of Direct Air Capture
Net-Zero
A balance where the total greenhouse gases emitted are equal to the amount removed, effectively reducing the net impact on the atmosphere. Net-zero emissions are often a target for businesses and governments. See: Carbon Neutrality
Permanent CO₂ Storage
Long-term storage solutions for CO₂, such as deep underground storage in geological formations, ensuring it remains out of the atmosphere for thousands of years. See: High Durability CDR
Point Source Carbon Capture
Capturing CO₂ directly at the emission source, such as a power plant or industrial facility, preventing it from entering the atmosphere. For more see: Direct Air Capture vs Point Source
Sorbent
A material that absorbs (takes in or dissolves molecules) or adsorbs (adheres molecules on its surface). Sorbents are used in various carbon capture processes to trap CO₂ from the air or emissions.
Sustainable Aviation Fuel (SAF)
Fuel produced from renewable sources that can reduce aviation emissions. SAF is a type of efuel that is made from green hydrogen and captured carbon dioxide. For more see: Sustainable Aviation Fuel (SAF)