Neukom Raphael, Barboza Luis A, Erb Michael P, Shi Feng, Emile-Geay Julien, Evans Michael N, Franke Jörg, Kaufman Darrell S, Lücke Lucie, Rehfeld Kira, Schurer Andrew, Zhu Feng, Brönnimann Stefan, Hakim Gregory J, Henley Benjamin J, Ljungqvist Fredrik Charpentier, McKay Nicholas, Valler Veronika, von Gunten Lucien
Oeschger Centre for Climate Change Research and Institute of Geography, University of Bern, Switzerland.
Escuela de Matematica-CIMPA, Universidad de Costa Rica, San Jose, Costa Rica.
Nat Geosci. 2019 Jun 12;12(8):643-649. doi: 10.1038/s41561-019-0400-0. Epub 2019 Jul 24.
Multi-decadal surface temperature changes may be forced by natural as well as anthropogenic factors, or arise unforced from the climate system. Distinguishing these factors is essential for estimating sensitivity to multiple climatic forcings and the amplitude of the unforced variability. Here we present 2,000-year-long global mean temperature reconstructions using seven different statistical methods that draw from a global collection of temperature-sensitive paleoclimate records. Our reconstructions display synchronous multi-decadal temperature fluctuations, which are coherent with one another and with fully forced CMIP5 millennial model simulations across the Common Era. The most significant attribution of pre-industrial (1300-1800 CE) variability at multi-decadal timescales is to volcanic aerosol forcing. Reconstructions and simulations qualitatively agree on the amplitude of the unforced global mean multi-decadal temperature variability, thereby increasing confidence in future projections of climate change on these timescales. The largest warming trends at timescales of 20 years and longer occur during the second half of the 20 century, highlighting the unusual character of the warming in recent decades.
数十年的地表温度变化可能由自然因素和人为因素共同驱动，也可能是气候系统自然产生的。区分这些因素对于评估对多种气候强迫的敏感性以及自然变率的幅度至关重要。在此，我们使用七种不同的统计方法，基于全球温度敏感型古气候记录集，给出了长达2000年的全球平均温度重建结果。我们的重建结果显示了同步的数十年温度波动，这些波动相互之间以及与整个公元时代完全受强迫的CMIP5千年模型模拟结果都是一致的。在数十年时间尺度上，工业化前（公元1300 - 1800年）变率的最主要归因是火山气溶胶强迫。重建结果和模拟结果在自然全球平均数十年温度变率的幅度上定性一致，从而增强了对这些时间尺度上未来气候变化预测的信心。20年及更长时间尺度上最大的变暖趋势出现在20世纪后半叶，突出了近几十年来变暖的异常特征。
