by Dr Werner L. Kutsch

Carbon sinks are the hype of the time. Some say they are at risk of being lost, others say they need to be increased. For some, nature-based carbon sinks will solve the entire climate change issue. For others, they are negligible or too uncertain to count on. The fact is, however, that if we want to establish credible strategies to mitigate climate change, we need to evaluate the status of the nature-based carbon sinks and storages. This represents a massive challenge if we want to do it right.

The European Union (EU) has included new targets to increase natural sinks into its portfolio of measures to fight climate change. Natural sinks refer to the removal of carbon dioxide (CO2) from the atmosphere and storing it long-term in forests, wetlands, soils and oceans. The EU regulatory framework currently under development calls for a scientifically-robust assessment of carbon removals. This is where ICOS has a role to play.


The EU regulatory framework calls for a scientifically-robust assessment of carbon removals. This is where ICOS has a role to play.

Dr Werner L. Kutsch, Director General of the Integrated Carbon Observation System (ICOS)

This issue of FLUXES addresses the potential and limitations of nature-based solutions for carbon ­removals from a scientific perspective: What can be measured? What conclusions can be drawn? What solutions seem adequate? The observational data produced by ICOS can support policy-makers in various ways. Robust data can help to identify whether and how strong a carbon sink is. Long-term and consistent data can produce reliable estimates of the sizes of the carbon pools and inform how these pools respond to environmental and management changes as the world transitions towards carbon neutrality.

To avoid the worst consequences of climate change, we absolutely must reduce our fossil fuel emissions. But if carbon removals will be absolutely needed to compensate and offset overshoot and unavoidable emissions – as nature is already helping by compensating almost half of the human-derived emissions – we need to be able to evaluate the nature-based solutions we have at hand. This issue of FLUXES sheds light on two such solutions: carbon storage on land and in the ocean via blue carbon. We at ICOS hope this ‘scientific voice’ will bring new perspectives and support those working with climate policies.