Carbon Dioxide Removal (CDR)

This briefing paper has also been published individually as a webpage: Carbon Dioxide Removal (CDR)

Authors: Jennifer Bird, George Hope, Dr Steve Smith and Dr Philippa Westbury

Media enquiries: grantham.media@imperial.ac.uk  
Policy enquiries: j.bird@imperial.ac.uk   

CDR is an umbrella term for techniques that can be used to deliver negative emissions. That is, they capture carbon dioxide (CO₂) from the air and store durably.

Carbon dioxide capture from air can happen through biological processes, industrial chemical processes, or rock weathering processes. Depending on the technique, the carbon can be stored in trees, plant matter, in the soil, deep underground, in the oceans, or in long-lived products. 

This background briefing explores the topic of carbon dioxide removal and how it relates to climate change.

Key points 

• Carbon Dioxide Removal (CDR) is an umbrella term for techniques that capture carbon dioxide from the air and store it durably, as a result of human activity. CDR and Carbon Capture and Storage (CCS) are not the same thing, although the terms are sometimes incorrectly used interchangeably.   
• CDR has three potential uses in reaching climate goals: in the near term, to reduce net emissions; in the medium term, to counterbalance residual emissions to achieve ‘net zero’; and in the longer term, to achieve net-negative emissions in order to lower global temperatures if they exceed acceptable levels. 
• Given the uncertainties, costs and resource constraints associated with CDR, pursuing rapid emissions reductions must be a priority to mitigate the risks of relying on large-scale CDR. 
• Globally, almost all current removals come from CDR on land, primarily via afforestation, reforestation and improved management of existing forests. In future, CDR from ‘novel’ technologies will need to scale up rapidly – even for a lower-CDR pathways - requiring investment to stimulate innovation and drive down technology costs. 
• Aligning climate and socio-ecological objectives in the development, deployment and regulation of CDR, while putting in place the appropriate regulatory frameworks, will help to ensure that co-benefits are realised and environmental harms are minimised.