To achieve climate neutrality, humanity needs to eliminate almost all anthropogenic emissions. Towards that end, permanent carbon dioxide removals (CDR) will be needed to compensate for the unavoidable emissions from sectors society deems vital and to lower atmospheric concentrations of greenhouse gases caused by historical emissions.
Ranging from industrial to nature-based processes, carbon removal techniques are not created equal. One major factor to distinguish them is their duration of carbon dioxide storage.
Biogenic sequestration by natural ecosystems that sequester carbon from the atmosphere and store it in biomass or soils are vulnerable to human and natural disturbances. Due to the risk that the carbon ecosystems store will be rereleased into the atmosphere, biogenic sequestration should be considered temporary. Natural ecosystems should be protected and their carbon uptake enhanced, but they should not be used to compensate residual anthropogenic emissions. Carbon removal methods that can store carbon for at least several centuries should be considered permanent and can therefore be used to compensate for residual emissions.
Support for carbon removals must not undermine efforts to slash emissions. To avoid this and to recognise the distinction between biogenic sequestration and permanent CDR, different targets and policies are necessary for emissions reduction, biogenic sequestration and permanent removals.
The EU needs a clear and comprehensive strategy that is mindful of the risks, challenges and opportunities of supporting the development and scale-up of a sufficient supply of permanent removals.
The CO2ol Down project, comprising representatives from academia, industry, and civil society, met during three full-day co-creation workshops and suggested the following building blocks to structure an appropriate strategy for permanent removals.