Modeling Soil Organic Carbon Dynamics in Response to Climate Change in Mount Everest Region of Nepal

This study provides an estimate of soil organic carbon (SOC) stock, projects future SOC stocks under different climate change scenarios, and considers impacts on topsoil SOC in Mount Everest region using the Rothamsted carbon (RothC) model. According to our estimates, the average SOC stock in the region is 85.34 t C/ha. The SOC stock for different land use types ranges from 29.67 to 156.87 t C/ha following the order: agricultural land > forest > pasture. A significant decreasing trend has been found between the SOC content and altitude. Climate change scenario derived from HADGEM2-CC global climate model at 30 second resolution driven by Representative Concentration Pathway (RCP) 4.5 and RCP8.5 indicates that the temperature in the region will increase by 2.87 and 3.51°C by 2050, respectively. Precipitation is projected to increase by 4.46 and 2.70% for RCP 4.5 and RCP 8.5, respectively. With this change in climatic condition, the average SOC stock in the region is projected to decrease significantly (by 8.56% for RCP 4.5 and 5.13% for RCP 8.5) by 2050 thereby increasing the amount of CO2 entering into the atmosphere by 50% on the average. Release of CO2 from soil carbon pool into the atmosphere is likely to enhance the warming trend through the SOC-climate positive feedback, exacerbating effects of climate change.