The change of soil carbon pools is reported as CO2 removed from the atmosphere or emissions into the atmosphere.
Means to create renewed interest towards the carbon concentration of agricultural lands will be introduced during the Paris climate accord period. During the 2020–2030 period, carbon sinks and CO2 emissions must be at the very least balanced. Preferably, a carbon net sink should be achieved. As the share of forest carbon sinks to be included in the accounting will be limited, emissions from other forms of land use will play a greater role.
According to a recent survey by Luke, the land use sector will likely not be a carbon net sink during the 2020–2030 period. The survey results indicate that carbon sinks from forest management and afforestation will not be enough to compensate for the emissions from deforestation and agriculture. That is why we should think about whether there are any means available to reduce the emissions or increase agricultural carbon sinks.
The survey results indicate that carbon sinks from forest management and afforestation will not be enough to compensate for the emissions from deforestation and agriculture.
The soil can act as a carbon sink if it collects more carbon from dead plants or due to soil management actions than is removed by decomposing organisms. Vegetation can also be a carbon sink if it annually grows by more than the amount of biomass removed from the land area. Cultivated peat soil is the most important source of emissions from agriculture; it generates more than half of all agricultural emissions.
According to the calculation method to be used, agricultural lands could become a carbon net sink if the total amount of emissions between 2021 and 2025 or 2026 and 2030 remains below the average of the emissions during the reference years, such as 2005–2007 or 2005–2009, multiplied by five. For this reason, reducing emissions during the period under review might be sufficient; turning total emissions into a carbon sink might not be necessary.
Emissions could be reduced, for example, by stopping the use of peat soil fields with low yields in production, targeting the clearing of new fields to mineral soil areas instead of peat soil areas, or by favouring perennials or a groundwater surface level that is higher than normal in the case of peat soil.
Measures that can be implemented for the large surface areas of mineral soil fields, such as the use of catch crops or other methods to increase the quantity of dead plant matter that remains in the soil, can be surprisingly effective means of increasing the carbon pool.
The next rural development programme will play a key role in the realisation of the emission reductions. If the goals are reached, agricultural emission reductions could become a success story for a new rural development programme that will move the production of food towards carbon neutrality.
Published in Finnish in Maaseudun Tulevaisuus on 7th of August 2017.