Climatic warming has greatly increased vegetation productivity in the extratropical Northern Hemisphere since the 1980s, but how long this positive relationship will continue remains unknown. Here we show changes in the effect of warming on Northern Hemisphere summer gross primary productivity for 2001–2100 using Earth system model outputs. The correlation between summer gross primary productivity and temperature decreases in temperate and boreal regions by the late twenty-first century, generally becoming significantly negative before 2070 in regions <60° N, though Arctic gross primary productivity continues to increase with further summer warming. The time when the correlation becomes negative is generally later than the time when summer temperature exceeds the optimal temperature for vegetation productivity, suggesting partial mitigation of the negative vegetation impacts of future warming with photosynthetic thermal acclimation. Our findings indicate that vegetation productivity could be impaired by climate change in the twenty-first century, which could negatively impact the global land carbon sink.

自 1980 年代以来，气候变暖极大地提高了温带北半球的植被生产力，但这种积极关系将持续多久仍是未知数。在这里，我们使用地球系统模型输出显示了 2001-2100 年变暖对北半球夏季总初级生产力影响的变化。到 21 世纪后期，温带和北方地区夏季总初级生产力与温度之间的相关性下降，在 2070 年之前，在<60° N 的地区通常会显着负相关，尽管随着夏季进一步变暖，北极总初级生产力继续增加。相关性变为负值的时间一般晚于夏季气温超过植被生产力最适温度的时间，表明光合热适应可以部分缓解未来变暖对植被的负面影响。我们的研究结果表明，二十一世纪的气候变化可能会损害植被生产力，这可能会对全球陆地碳汇产生负面影响。