Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544.
Proc Natl Acad Sci U S A. 2013 Oct 15;110(42):16730-5. doi: 10.1073/pnas.1314047110. Epub 2013 Sep 23.
Previous studies have demonstrated the importance of enhanced vegetation growth under future elevated atmospheric CO2 for 21st century climate warming. Surprisingly no study has completed an analogous assessment for the historical period, during which emissions of greenhouse gases increased rapidly and land-use changes (LUC) dramatically altered terrestrial carbon sources and sinks. Using the Geophysical Fluid Dynamics Laboratory comprehensive Earth System Model ESM2G and a reconstruction of the LUC, we estimate that enhanced vegetation growth has lowered the historical atmospheric CO2 concentration by 85 ppm, avoiding an additional 0.31 ± 0.06 °C warming. We demonstrate that without enhanced vegetation growth the total residual terrestrial carbon flux (i.e., the net land flux minus LUC flux) would be a source of 65-82 Gt of carbon (GtC) to atmosphere instead of the historical residual carbon sink of 186-192 GtC, a carbon saving of 251-274 GtC.
先前的研究表明，在未来大气二氧化碳升高的情况下，增强植被生长对于 21 世纪的气候变暖至关重要。令人惊讶的是，没有研究对历史时期进行类似的评估，在此期间，温室气体排放迅速增加，土地利用变化（LUC）极大地改变了陆地碳源和汇。本研究使用地球物理流体动力学实验室综合地球系统模型 ESM2G 和 LUC 的重建，我们估计增强的植被生长降低了历史大气 CO2 浓度 85 ppm，避免了额外的 0.31 ± 0.06 °C 的变暖。我们证明，如果没有增强的植被生长，总剩余陆地碳通量（即净陆地通量减去 LUC 通量）将成为向大气中排放 65-82 Gt 碳（GtC）的源，而不是历史上剩余的 186-192 GtC 碳汇，碳储量节省了 251-274 GtC。
