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Increasing carbon sink is possible but there are consequences

With measures in the forest, it is possible to increase the carbon sink by between two and 10 million tonnes of carbon dioxide per year. This was shown in an analysis by the Norwegian Forestry Agency of how individual measures affect net uptake in the forest, for example reduced felling, increased minimum permitted age for felling, reduced grazing damage from moose and other game or increased nitrogen fertilization. Source: Timberbiz

A halving of game grazing damage can contribute to the carbon sink increasing by roughly five million tonnes per year until 2100.

The report states the estimated potential of some individual measures to increase the carbon sink in the forest. The effect of the measures cannot be summed up because they may partly affect the same ground. In the analysis, certain measures have been carried out on larger areas than others, which also affects the effect on the carbon sink: Examples of measures included in the analysis are:

  • Reduced felling. If logging is reduced to 90% of today’s logging level, the carbon sink can increase by just under 10 million tons of carbon dioxide per year until the year 2100.
  • Extended orbital period. If the minimum permitted age for felling is raised by 30%, the carbon sink can increase by roughly seven million tons of carbon dioxide per year until 2100. The effect is mainly due to temporarily reduced felling in the period up to the year 2050.
  • Halving game grazing damage where moose and other deer graze in young forest, can contribute to increasing the carbon sink by roughly five million tons of carbon dioxide per year until 2100.
  • Increased area nitrogen fertilization to 150,000 hectares per year (4.5 times more than today, especially in northern Sweden) can contribute to the carbon sink increasing by roughly two million tons of carbon dioxide per year until 2100.
  • According to the results doubling the area of nature conservation allocations, where forest is excluded from production, does not contribute to increased carbon sinks if today’s felling volume is maintained in the cultivated forest.

The analysis is based on the forestry impact analyzes (SKA 22) that the Norwegian Forestry Agency presented last autumn. It does not include the effect of the measures on the entire climate benefit of the forest because the possibilities of replacing fossil materials and fuels with products from the forest have not been calculated.

A reduction in felling may mean that the supply of wood raw materials decreases, which may lead to an increased demand for fossil raw materials or an increased import of wood raw materials from other countries. Emissions of carbon dioxide can thus be moved to other countries or other sectors.

The results also indicate that an increased use of clear-cut forestry (through selective felling and gap cutting) to a quarter of the forest has no significant impact on the carbon sink. At the same time, the analyzes indicate that an increase in the area rejuvenated with deciduous trees (three times higher proportion) can negatively affect the carbon sink.

This clearly shows that forestry measures can be of great importance in continuing to bind carbon dioxide in the forest and contribute to achieving the climate goals. This is particularly important in a changing climate that increases the risk of carbon losses in the forest, says climate specialist Giuliana Zanchi, Norwegian Forestry Agency.

The risk of damage to the forest will increase in the future due to climate change. Measures that increase the carbon sink lead to an increased supply of wood, which generally increases the risk of damage. However, some of the measures above can lead to more varied forests or a more varied forest landscape (for example, an increased proportion of deciduous trees), which can reduce the risk of damage.

Sweden’s territorial emissions of greenhouse gases (emissions that occur within Sweden’s borders) amounted to 48 million tonnes of carbon dioxide equivalents in 2021, excluding the land use sector.

The total net uptake of greenhouse gases within the entire land use sector (LULUCF) was just under 42 million tonnes of carbon dioxide equivalents in 2021. At that time, the net uptake in living biomass in trees as well as dead wood and wood products amounted to 37 million tonnes of carbon dioxide equivalents. The latter task is relevant to compare the reported model results with.

The analysis has been carried out using the same models as in the Forest impact analyzes reported in 2022 (SKA 22). The effect has been calculated for each of the measures based on how the forest is managed today. The carbon pools included are biomass in trees, dead wood and wood products, but not soil carbon.