ABSTRACT Existing scientific literature and international assessments, such as those by the Intergovernmental Panel on Climate Change, provide a wide range of projections for global mean sea level rise (SLR) in the twenty-first century. At the local scale, the ranges or uncertainties of projections are even larger. There is a pressing need to compile plausible local SLR scenarios to aid coastal communities with adaptation. Here we develop three local SLR scenarios for Canadian tide-gauge stations for the twenty-first century (Low, Intermediate, and High). Our Low Scenario is based on projections under the Representative Concentration Pathway 4.5 (RCP4.5) scaled down to the present global SLR rate. Our Intermediate Scenario is based on projections under the Representative Concentration Pathway 8.5 (RCP8.5), and our High Scenario is based on the RCP8.5 projections with an adjusted contribution from the Antarctic ice sheet. For all three scenarios, we use vertical land motion (VLM) from global positioning systems (GPS) data corrected for the present-day melt of glaciers and ice sheets instead of the commonly used VLM from a glacial isostatic adjustment (GIA) model. The GPS data include not only GIA but also other processes affecting VLM. For each scenario, larger SLR is projected along the southeastern Atlantic coast, the Pacific coast, and the Beaufort Sea coast than along other Canadian coasts in the twenty-first century. Under the Low, Intermediate, and High Scenarios, the median relative sea level along the southeastern Atlantic coast may rise by as much as 0.35, 0.82, and 0.96 m, respectively, over 2010–2100. The proposed scenarios allow coastal engineers and managers to consider multiple future conditions and develop multiple response options, as well as choose the most suitable option according to the risk tolerance of infrastructure.

中文翻译：

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加拿大各地潮位站 21 世纪平均海平面上升的情景

摘要 现有的科学文献和国际评估，例如政府间气候变化专门委员会的评估，为 21 世纪的全球平均海平面上升 (SLR) 提供了广泛的预测。在局部尺度上，预测的范围或不确定性甚至更大。迫切需要编制合理的当地 SLR 情景，以帮助沿海社区进行适应。在这里，我们为 21 世纪的加拿大潮汐站开发了三个本地 SLR 场景（低、中和高）。我们的低情景基于代表性浓度路径 4.5 (RCP4.5) 下的预测，该预测按比例缩小到目前的全球 SLR 率。我们的中级情景基于代表性浓度路径 8.5 (RCP8.5) 下的预测，我们的高情景基于 RCP8.5 预测，并调整了南极冰盖的贡献。对于所有三种情况，我们使用来自全球定位系统 (GPS) 数据的垂直陆地运动 (VLM)，这些数据针对当今冰川和冰盖的融化进行了校正，而不是来自冰川均衡调整 (GIA) 模型的常用 VLM。GPS 数据不仅包括 GIA，还包括影响 VLM 的其他过程。对于每种情景，21 世纪东南大西洋沿岸、太平洋沿岸和波弗特海沿岸的 SLR 预计比其他加拿大海岸的 SLR 更大。在低、中、高情景下，2010-2100 年大西洋东南沿海相对海平面中位数可能分别上升 0.35、0.82 和 0.96 m。