Increases in the magnitude, frequency, and duration of warm seawater temperatures are causing mass coral mortality events across the globe. Although, even during the most extensive bleaching events, some reefs escape exposure to severe stress, constituting potential refugia. Here, we identify present-day climate refugia on the Great Barrier Reef (GBR) and project their persistence into the future. To do this, we apply semi-dynamic downscaling to an ensemble of climate projections released for the IPCC's recent sixth Assessment Report. We find that GBR locations experiencing the least thermal stress over the past 20 years have done so because of their oceanographic circumstance, which implies that longer-term persistence of climate refugia is feasible. Specifically, tidal and wind mixing of warm water away from the sea surface appears to provide relief from warming. However, on average this relative advantage only persists until global warming exceeds ~3°C.

中文翻译：

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当全球变暖超过 3°C 时，大堡礁的气候避难所失败

温暖海水温度的幅度、频率和持续时间的增加正在全球范围内导致大规模的珊瑚死亡事件。虽然，即使在最广泛的白化事件中，一些珊瑚礁也能逃脱严重的压力，构成潜在的避难所。在这里，我们确定了当今大堡礁 (GBR) 上的气候避难所，并将它们的持久性投射到未来。为此，我们将半动态降尺度应用于为 IPCC 最近的第六次评估报告发布的一组气候预测。我们发现，在过去 20 年中，GBR 地区经历的热应力最小，是因为它们的海洋环境，这意味着气候避难所的长期持续存在是可行的。具体来说，远离海面的暖水的潮汐和风混合似乎可以缓解变暖。然而，平均而言，这种相对优势只会持续到全球变暖超过约 3°C。