Net primary productivity (NPP) is an important indicator of plant dynamics and the net carbon exchange between the terrestrial ecosystem and atmosphere. Both the long-term shifts in climate mean (climate change) and short-term variations around the climate mean (climate variability) have impacts on NPP but studies examining both aspects of climate variations are rare especially in the data-scarce regions such as the Tibetan Plateau (TP). Here, we used a dynamic vegetation model to investigate the impacts of the changes and variabilities in temperature, precipitation, cloud cover and CO₂ on NPP on the TP. The simulated NPP was evaluated using field and Moderate-Resolution Imaging Spectroradiometer NPP and was found to be reasonable. At monthly time scale, NPP significantly correlated concurrently and at 1-month lag with temperature, precipitation and cloud cover (coefficient of determination, R², in 0.52–0.77). Annual NPP variability was high (low) where mean annual NPP was low (high). The effects of annual precipitation, cloud cover and temperature variability on annual NPP variability were spatially heterogeneous, and temperature variability appeared to be the dominant factor (R² of 0.74). Whereas, NPP changes were very similar to CO₂ increases across the TP (spatial correlation of 0.60), indicating that long-term changes in NPP were dominated by CO₂ increases. For both variability and long-term changes in NPP, temperature was the major factor of influence (highest spatial correlation of 0.67). These findings could assist in making informed mitigation policies on the impacts of climate change and variability on ecosystem and local nomadic communities.

净初级生产力（NPP）是植物动态以及陆地生态系统与大气之间净碳交换的重要指标。气候平均值的长期变化（气候变化）和围绕气候平均值的短期变化（气候变异性）都对NPP产生影响，但是研究气候变化的两个方面的研究很少，尤其是在数据稀缺的地区，如青藏高原（TP）。在这里，我们使用动态植被模型来研究温度，降水，云量和CO ₂变化和变化的影响在TP上的NPP上。使用现场和中分辨率成像光谱仪NPP对模拟的NPP进行了评估，发现它是合理的。在每月的时间尺度上，NPP与温度，降水和云量的变化同时且在滞后1个月时显着相关（测定系数R ²为0.52-0.77）。年度NPP变异性较高（较低），而平均年度NPP较低（较高）。年降水量，云量和温度变化对年NPP变化的影响在空间上是不均匀的，温度变化似乎是主要因素（R ²为0.74）。而NPP的变化与CO ₂非常相似整个TP的增加（空间相关性为0.60），表明NPP的长期变化主要由CO _2的增加决定。对于NPP的可变性和长期变化，温度是影响的主要因素（最高空间相关性为0.67）。这些发现可以帮助制定关于气候变化和多变性对生态系统和当地游牧社区影响的知情缓解政策。