LULC changes in Türkiye's mountains for the 2000-2022 period and its implications on national GHG emissions.

Given the ecological significance and extensive coverage of mountainous regions in Türkiye, this study evaluates the effects of land use and land cover (LULC) changes in these areas on national greenhouse gas (GHG) emissions between 2000 and 2022. Collect Earth (CE), an open-source program developed by the Food and Agriculture Organization of the United Nations (FAO), was used to monitor the LULC changes. Collect Earth monitoring relies on high-resolution imagery from Google Earth and Bing Maps, enabling detailed plot-level assessments from local to national scales. The coefficients and emission factors to estimate GHG emission and removals were taken from the most recent National GHG Inventory Report (NIR) to ensure consistency and comparability. The land monitoring system revealed that 60.96 million hectares, constituting more than three-fourths of the country, are classified as mountainous. During the monitoring period, the settlement was the land use class with the most significant proportional increase (30.36%), mainly consuming cropland and grassland. Our results revealed that cropland (0.05%) and grassland (2.19%) areas shrank, while forestland (0.28%) and reservoir areas (6.03%) increased since the year 2000. Even though net forest cover (afforestation-deforestation) increased by around 59.3 Kha, the sole forest-related conversions increased the GHG emissions by 25.1 Mt CO₂eq. The total effect of LULC changes on the GHG balance was a net 47.1 Mt CO₂eq of emissions. Thus, LULC changes in Türkiye's mountainous areas acted as a net emission source, adding over 2 MtCO₂eq annually during the 20-year period.