Clarifying what is meant by greenhouse gas ‘removals’ and categorising types of ‘removal-related activities’

There is broad recognition that removals of carbon dioxide and other greenhouse gases will be required for counter-balancing emissions from hard-to-abate sectors to achieve net zero, and will also be necessary in the increasingly likely event of an emissions overshoot in order to return cumulative emissions and temperature change below target levels. However, the term ‘removal’ is open to imprecise usage, which is likely to result in confusion over which activities policy-makers, investors and offset buyers wish to support, and what project developers and technology providers actually deliver. This commentary paper aims to clarify what is meant by ‘removals’ by analysing the definitions from prominent sources and by proposing a precise definition of the term. The paper also identifies a further source of confusion, which is that ‘removals’ is often used as a shorthand to refer to removal-related activities that fulfil specific characteristics. Rather than adjudicate on shorthand linguistic conventions we suggest that a more precise approach is to clearly specify the types of removal-related activities that are intended for support. We offer some remarks on the relative mitigation value of different types of removal-related activity, noting that ultimately all actions that achieve net removals or emission reductions help to address climate change.