Estimating natural nitrous oxide emissions from the Qinghai–Tibetan Plateau using a process-based model: Historical spatiotemporal patterns and future trends

• TRIPLEX-GHG model was validated and used to estimate the natural annual N 2 O fluxes from the Qinghai-Tibetan Plateau . • The total natural N 2 O emissions of the Qinghai-Tibetan Plateau showed a slight increasing trend from 1970 to 2017. • Temperature is a dominant factor for N 2 O emissions on the Qinghai-Tibetan Plateau. • Under the future warmer and wetter scenario, N 2 O emissions of the Qinghai-Tibetan Plateau will continue to increase. Fluctuations in natural nitrous oxide emissions (N 2 O) are not fully understood, especially on the Qinghai–Tibetan Plateau. In order to characterize the differences in historical N 2 O variations among different regions of the Qinghai-Tibetan Plateau and investigate how a warmer and wetter climate change would affect the N 2 O fluxes over the Qinghai-Tibetan Plateau, a process-based model (TRIPLEX-GHG) has been validated using 14 sites with annual N 2 O emission fluxes, and is used to estimate the spatiotemporal patterns of natural N 2 O fluxes, and predict its future trend for the Qinghai-Tibetan Plateau (the temperature increasing by 1.5 °C and the precipitation increasing by 10%). Considering the model performance evaluation indicators (R 2 =0.83, rRMSE=44.6%, PBIAS=7.18%), the performance of the model for simulating annual N 2 O fluxes is “moderate”. The estimated average total natural N 2 O emissions of the Qinghai-Tibetan Plateau from 1970 to 2017 were 0.313 Tg N yr −1 , ranging from 0.305 Tg N yr −1 (1983) to 0.325 Tg N yr −1 (2006). The estimated total natural N 2 O emissions of the Qinghai-Tibetan Plateau slightly increased from 1970 to 2017, with a mean increase of 0.0002 Tg N yr −1 . Between the 1970s and 2010s, most increases in N 2 O flux were observed in the northern and southeastern regions of the Qinghai-Tibetan Plateau. The area in which the rate of N 2 O released was greater than 15 µg N m − 2 h − 1 was mainly found in plateau temperate regions. Regions with relatively high temperatures released more N 2 O, which indicates that temperature is a dominant factor for N 2 O emissions in high-altitude regions. Natural N 2 O emissions of the Qinghai-Tibetan Plateau will increase up to 0.335 Tg N yr −1 (by approximately 6.13%) by 2050 if the climate continues to become warmer and wetter.