Glacier mass loss is recognized as a major contributor to current sea level rise. However, large uncertainties remain in projections of glacier mass loss on global and regional scales. We present an ensemble of 288 glacier mass and area change projections for the 21st century based on 11 glacier models using up to 10 general circulation models and four Representative Concentration Pathways (RCPs) as boundary conditions. We partition the total uncertainty into the individual contributions caused by glacier models, general circulation models, RCPs, and natural variability. We find that emission scenario uncertainty is growing throughout the 21st century and is the largest source of uncertainty by 2100. The relative importance of glacier model uncertainty decreases over time, but it is the greatest source of uncertainty until the middle of this century. The projection uncertainty associated with natural variability is small on the global scale but can be large on regional scales. The projected global mass loss by 2100 relative to 2015 (79 ± 56 mm sea level equivalent for RCP2.6, 159 ± 86 mm sea level equivalent for RCP8.5) is lower than, but well within, the uncertainty range of previous projections.

中文翻译：

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划分全球冰川大规模变化整体投影的不确定性

冰川质量损失被认为是当前海平面上升的主要因素。但是，在全球和区域范围内，冰川质量损失的预测仍存在很大的不确定性。基于11个冰川模型，我们使用多达10个普通环流模型和4个代表性浓度路径（RCP）作为边界条件，给出了21世纪288个冰川的质量和面积变化预测的集合。我们将总不确定性划分为由冰川模型，一般循环模型，RCP和自然变异性引起的单个贡献。我们发现，排放情景的不确定性在整个21世纪不断增长，并且是2100年不确定性的最大来源。冰川模型不确定性的相对重要性随着时间的推移而降低，但这是本世纪中叶之前不确定性的最大来源。与自然可变性相关的预测不确定性在全球范围内很小，但在区域范围内可能很大。与2015年相比，到2100年的预计全球质量损失（RCP2.6相当于79±56毫米海平面，RCP8.5相当于159±86毫米海平面）虽然低于但仍在先前预测的不确定性范围内。