Volume 2
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.

Nature-based carbon sinks have a dual role in climate action

➔ Average human influence in the global carbon cycle in GtC per year, gigatonnes of carbon, for the decade 2012-2021. (Adapted from Global Carbon Project 2022)
Carbon emissions and sinks vary between the years

➔ Annual mean net ecosystem exchange of central Europe in 2018-2021.
Forest carbon sinks under pressure

➔ As a natural carbon sink, forests are central to our fight against climate change. At the same time, forests are under immense pressure, from increasing harvest demands to natural disturbances associated with the warming climate. What can be done to increase the forest carbon sink?
Coastal ecosystems, reservoirs of life

➔ Coastal ecosystems sequester carbon from the atmosphere, help maintain high biodiversity levels, enhance water quality, protect coasts from extreme tidal events, and are an important resource for coastal communities. Despite the benefits they provide, coastal ecosystems are still poorly understood and face life-threatening pressures from human activities. As European coastlines lose their natural habitats rapidly, time is running out for action.
Carbon farming - a path to more sustainable agriculture

➔ Agriculture causes about 11% of the European Union's greenhouse gas emissions1. The share is noteworthy because the two major emissions – nitrous oxide and methane – are very powerful greenhouse gases. Farming methods which tackle agricultural emissions are often referred to as carbon farming. This article discusses the role of agricultural soils in carbon farming, since only soils can be part of nature-based climate solutions.
The complex chemistry behind the alarming growth in methane

➔ The natural carbon sinks might support u us in our last stretch towards carbon neutrality. However, the atmosphere is very complex. Methane concentrations have been on the rise since 2007, with a record growth rate in Europe in 2020-2021. Reasons for the growth are human-induced emissions, the chemical interplay of gases, and increased natural emissions caused by climate change.