南京大学张永光等研究人员揭示全球CO₂排放量下降对植被光合作用的影响。这一研究成果发表在2020年12月11日出版的国际学术期刊《科学》上。

通过使用多个长期的卫星和地面数据集，研究人员表明，从1982年到2015年，全球大多数陆地区域的全球CO₂施肥效应（CFE）下降了，这与养分浓度变化和土壤水的可用性密切相关。当前的碳循环模型也显示出CFE趋势的下降，尽管这比全球观测的结果要弱得多。

大气中二氧化碳量的增加迫使陆地碳汇的趋势不断下降，这意味着对气候系统的负面反馈减弱，以及对未来减缓气候变暖战略的社会依赖性增强。

据悉，CO₂浓度升高（即CFE）推动植被生产力提高，这对气候变暖保持了重要的负反馈作用，但CFE的时间动态尚不清楚。

附：英文原文

Title: Recent global decline of CO2 fertilization effects on vegetation photosynthesis

Author: Songhan Wang, Yongguang Zhang, Weimin Ju, Jing M. Chen, Philippe Ciais, Alessandro Cescatti, Jordi Sardans, Ivan A. Janssens, Mousong Wu, Joseph A. Berry, Elliott Campbell, Marcos Fernández-Martínez, Ramdane Alkama, Stephen Sitch, Pierre Friedlingstein, William K. Smith, Wenping Yuan, Wei He, Danica Lombardozzi, Markus Kautz, Dan Zhu, Sebastian Lienert, Etsushi Kato, Benjamin Poulter, Tanja G. M. Sanders, Inken Krüger, Rong Wang, Ning Zeng, Hanqin Tian, Nicolas Vuichard, Atul K. Jain, Andy Wiltshire, Vanessa Haverd, Daniel S. Goll, Josep Peuelas

Issue&Volume: 2020/12/11

Abstract: The enhanced vegetation productivity driven by increased concentrations of carbon dioxide (CO2) [i.e., the CO2 fertilization effect (CFE)] sustains an important negative feedback on climate warming, but the temporal dynamics of CFE remain unclear. Using multiple long-term satellite- and ground-based datasets, we showed that global CFE has declined across most terrestrial regions of the globe from 1982 to 2015, correlating well with changing nutrient concentrations and availability of soil water. Current carbon cycle models also demonstrate a declining CFE trend, albeit one substantially weaker than that from the global observations. This declining trend in the forcing of terrestrial carbon sinks by increasing amounts of atmospheric CO2 implies a weakening negative feedback on the climatic system and increased societal dependence on future strategies to mitigate climate warming.

DOI: 10.1126/science.abb7772

Source: https://science.sciencemag.org/content/370/6522/1295