Role of Land Cover in Finland's Greenhouse Gas Emissions

We present regionally aggregated emissions of greenhouse gases (GHG) from five land cover categories in Finland: artificial surfaces, arable land, forest, waterbodies, and wetlands. Carbon (C) sequestration to managed forests and unmanaged wetlands was also assessed. Models FRES and ALas were applied for emissions (CO, CH, NO) from artificial surfaces and agriculture, and PREBAS for forest growth and C balance. Empirical emission coefficients were used to estimate emissions from drained forested peatland (CH, NO), cropland (CO), waterbodies (CH, CO), peat production sites and undrained mires (CH, CO, NO). We calculated gross emissions of 147.2 ± 6.8 TgCOeq yr for 18 administrative units covering mainland Finland, using data representative of the period 2017-2025. Emissions from energy production, industrial processes, road traffic and other sources in artificial surfaces amounted to 45.7 ± 2.0 TgCOeq yr. The loss of C in forest harvesting was the largest emission source in the LULUCF sector, in total 59.8 ± 3.3 TgCOeq yr. Emissions from domestic livestock production, field cultivation and organic soils added up to 12.2 ± 3.5 TgCOeq yr from arable land. Rivers and lakes (13.4 ± 1.9 TgCOeq yr) as well as undrained mires and peat production sites (14.7 ± 1.8 TgCOeq yr) increased the total GHG fluxes. The C sequestration from the atmosphere was 93.2 ± 13.7 TgCOeq yr. with the main sink in forest on mineral soil (79.9 ± 12.2 TgCOeq yr). All sinks compensated 63% of total emissions and thus the net emissions were 53.9 ± 15.3 TgCOeq yr, or a net GHG flux per capita of 9.8 MgCOeq yr.