Background report: responsible use of temporary CO2 removal
The Netherlands Scientific Climate Council (WKR) was asked when and under what conditions temporary carbon dioxide removal (CDR) can be used responsibly to meet the climate goals of the Paris Agreement. The core question addressed is when the use of temporary CDR is justified. The WKR's answer to this question is presented in its background report, 'Responsible use of temporary carbon dioxide removal'.
Permanent and temporary CDR
On July 10, 2024, the WKR issued its advisory report 'Clearing the Air?. According to the council, Dutch carbon dioxide removal policy should prioritize permanent CDR methods. Specifically, the council recommended that only permanent CDR should be used for compensating fossil and other long-lived greenhouse gas emissions. The council also suggested that temporary CDR should only be encouraged in the Netherlands as part of other policies.
With temporary CDR, carbon is usually sequestered for only a few decades and may be released back into the atmosphere over the same time scale. In contrast, permanent CDR stores carbon for at least several centuries. Much of the Netherlands' emissions contain fossil carbon that was sequestered millions of years ago and is 'additional' to the carbon that already circulates in the Earth's oceans, biosphere, and atmosphere as part of the short carbon cycle. This characteristic distinguishes fossil carbon from biogenic carbon from a climate perspective. The council advised that these fossil emissions should only be compensated with permanent CDR.
Relevance of temporary CDR
Temporary CDR is an important issue. On one hand, temporary CDR is heavily relied upon in global and European Union plans aimed at achieving climate neutrality and limiting global warming. On the other hand, temporary carbon storage carries a high risk of premature CO2 release, partly due to the same global warming it seeks to mitigate. The effects of climate change, including an increase in forest fires and periods of drought and heat, may reduce the ability of forests and soils to absorb CO2 or even cause them to release CO2.
The WKR concludes, among other things, that temporary CDR can be used to compensate for emissions of non-fossil CO2 and methane derived from biological processes. Important conditions are that the CDR cancels out the warming effect of those emissions at any point in time, and that emissions are hard-to-abate.
Decision Tree
Based on scientific insights and principles, the WKR has developed a decision tree to determine whether a specific greenhouse gas emission is eligible for compensation with temporary CDR.
To meet climate goals, the use of temporary CDR is only justified for a limited part of greenhouse gas emissions. The report also draws attention to the fact that countries' emission inventories do allow fossil emissions to be compensated with temporary CDR. This is not in line with the council’s earlier recommendation that fossil emissions should only be compensated with permanent CDR.
