Carbon Dioxide Removal (CDR): What is Sustainable and Just?

By Duncan McLaren and Olaf Corry

As atmospheric greenhouse gas (GHG) concentrations continue to rise apace and global temperatures and climate impacts accelerate due to insufficient global action, many are placing hopes and expectations in large scale anthropogenic ‘carbon dioxide removal’ (CDR) to balance the global carbon budget. 

CDR comprises a range of ideas and schemes that aim to draw down atmospheric carbon dioxide (which is already at harmful levels) and store it safely. In pursuing a maximum of a 1.5°C temperature rise at 2100, the Intergovernmental Panel for Climate Change (IPCC) Reports include many potentially unsustainable scenarios with removal of between 6 and 11 billion tonnes of CO2 (6-11 Gt-CO2) every year for 50 years.  This would be a staggering amount of removal and storage and raises a host of challenging questions not only about feasibility and effectiveness, but also about safety, sustainability, legality, justice, ethics and geo-politics. 

Questions include:

- Are such rates of removal even possible in the face of technical, economic and social limits?

- Whose continued emissions would be counterbalanced with CDR? 

- What would a world of large-scale CDR look like in terms of human rights, sustainability and geopolitical risks?

- What do such calculations assume about continual economic growth and global inequalities? 

- Can CDR be pursued without deterring urgently needed acceleration of emissions cuts? 

This briefing paper offers some answers to these questions, highlighting uncertainties surrounding prospects for CDR, and social, environmental and human rights harms that may arise if we place too much trust in CDR – especially if CDR is treated as interchangeable with emissions reductions. We outline a pathway that restrains climate change and avoids unsafe, unjust and unsustainable technofixes.