Shakun Jeremy D, Clark Peter U, He Feng, Lifton Nathaniel A, Liu Zhengyu, Otto-Bliesner Bette L
Department of Earth and Environmental Sciences, Boston College, Chestnut Hill, MA 02467, USA.
College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, USA.
Nat Commun. 2015 Aug 21;6:8059. doi: 10.1038/ncomms9059.
The ongoing retreat of glaciers globally is one of the clearest manifestations of recent global warming associated with rising greenhouse gas concentrations. By comparison, the importance of greenhouse gases in driving glacier retreat during the most recent deglaciation, the last major interval of global warming, is unclear due to uncertainties in the timing of retreat around the world. Here we use recently improved cosmogenic-nuclide production-rate calibrations to recalculate the ages of 1,116 glacial boulders from 195 moraines that provide broad coverage of retreat in mid-to-low-latitude regions. This revised history, in conjunction with transient climate model simulations, suggests that while several regional-scale forcings, including insolation, ice sheets and ocean circulation, modulated glacier responses regionally, they are unable to account for global-scale retreat, which is most likely related to increasing greenhouse gas concentrations.
全球冰川持续消退是近期与温室气体浓度上升相关的全球变暖最明显的表现之一。相比之下，在最近一次冰消期（全球变暖的最后一个主要阶段），由于世界各地冰川消退时间的不确定性，温室气体在推动冰川消退中的作用尚不清楚。在此，我们利用最近改进的宇宙成因核素生产率校准方法，重新计算了来自195个冰碛的1116块冰川巨石的年龄，这些冰碛广泛覆盖了中低纬度地区的冰川消退情况。这一修订后的历史记录，结合瞬态气候模型模拟结果表明，虽然包括日照、冰盖和海洋环流在内的几种区域尺度强迫因素在区域上调节了冰川的响应，但它们无法解释全球尺度的冰川消退，而这很可能与温室气体浓度增加有关。
