Extensification and afforestation of cultivated mineral soil for climate change mitigation in Finland

• The grassland extensification can reduce future soil carbon emission by ? 1 ‰ thus below proposed Paris 4‰ initiative. afforestation could offset CO 2 emissions at a maximum rate Mg C ha ?1 y -1 only after 30 years delay. Offsetting average person emissions, 10300 kg year , requires of 1.4 spruce. Land use change agricultural soils cannot play major role in Finland’s ambitious goal being neutral 2035. nation-wide sinks from land (LUC), e.g. fields and afforestation, is considered as climate mitigation option. We evaluated the LUC potential for reducing creating annual ecosystem Finland. used statistics, forest growth model MOTTI, Yasso07, RCP8.5 scenario. stock (SOC) extensified grasslands showed on less loss than cropland, between 0.17 initially, 0.08 50 years. such gain was comparison to SOC 1.4‰ 0.7‰ which lower initiative offsetting global anthropogenic emissions. Furthermore, estimated expected increase above pre-LUC levels with lag. Estimated sink when compared continuous cultivation varied depending dominant tree species fertility 0.19 (1.7‰ spruce medium fertile soil) 0.46 (3.7‰ silver birch highly soil). Future total biomass attributed ranged 1.65 2.44 . Combined created present lag annually 0.01 4% national net long delay small scale reduction highlighted importance employing additional tools reach neutrality targets due next 15 or