Future Projection of CO₂ Absorption and N₂O Emissions of the South Korean Forests under Climate Change Scenarios: Toward Net-Zero CO₂ Emissions by 2050 and Beyond

Forests mitigate climate change by absorbing CO₂. However, N₂O emissions in forests, which has 298 times larger global warming potential than CO₂, can diminish the climate mitigation role of forests. Thus, it is crucial to project not only CO₂ absorption but also N₂O emissions in forests to provide a scientific basis for the 1.5 °C Paris Agreement goal. This study used a biogeochemical model, called FBD-CAN, to project CO₂ absorption and N₂O emissions of South Korean forests from 2021 to 2080 under three climate scenarios, including the current climate, Representative Concentration Pathway (RCP) 4.5, and RCP 8.5. From 2021 to 2080, CO₂ absorption decreased from 5.0 to 1.4 Mg CO₂ ha⁻¹ year⁻¹ under the current climate with the aging of forests, while N₂O emissions increased from 0.25 to 0.33 Mg CO₂ eq. ha⁻¹ year⁻¹. Climate change accelerated the decreasing trend in CO₂ absorption and the increasing trend in N₂O emissions. The subalpine region had a faster decreasing trend in CO₂ absorption than the central and southern regions due to its older stand age. These findings provide scientific references for future greenhouse gas reduction plans and broaden our knowledge of the impacts of climate change on the climate mitigation role of forests.