Elevated CO₂ concentrations increase photosynthesis and, potentially, net ecosystem production (NEP), meaning a greater CO₂ uptake. Climate, nutrients and ecosystem structure, however, influence the effect of increasing CO₂. Here we analysed global NEP from MACC-II and Jena CarboScope atmospheric inversions and ten dynamic global vegetation models (TRENDY), using statistical models to attribute the trends in NEP to its potential drivers: CO₂, climatic variables and land-use change. We found that an increased CO₂ was consistently associated with an increased NEP (1995–2014). Conversely, increased temperatures were negatively associated with NEP. Using the two atmospheric inversions and TRENDY, the estimated global sensitivities for CO₂ were 6.0 ± 0.1, 8.1 ± 0.3 and 3.1 ± 0.1 PgC per 100 ppm (~1 °C increase), and −0.5 ± 0.2, −0.9 ± 0.4 and −1.1 ± 0.1 PgC °C⁻¹ for temperature. These results indicate a positive CO₂ effect on terrestrial C sinks that is constrained by climate warming.

升高的CO ₂浓度会增加光合作用，并有可能增加生态系统净产量（NEP），这意味着更大的CO ₂吸收量。但是，气候，养分和生态系统结构会影响增加CO ₂的效果。在这里，我们使用统计模型将NEP的趋势归因于其潜在驱动因素：CO ₂，气候变量和土地利用变化，分析了MACC-II和Jena CarboScope大气反演的全球NEP以及十种动态全球植被模型（TRENDY）。我们发现增加的CO ₂一直与NEP增加有关（1995-2014）。相反，温度升高与NEP呈负相关。使用两个大气反转和趋势，估计的CO ₂总体敏感性为每100 ppm 6.0±0.1、8.1±0.3和3.1±0.1 PgC（增加约1°C），以及-0.5±0.2，-0.9±0.4和−1.1±0.1 PgC°C ^-1（温度）。这些结果表明，受气候变暖限制，CO ₂对陆地碳汇具有积极作用。