Projected Marine Heatwaves in the 21st Century and the Potential for Ecological Impact
Projected Marine Heatwaves in the 21st Century and the Potential for Ecological Impact
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DOI：
10.3389/fmars.2019.00734
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发表时间：
2019-12-04
影响因子：
3.7
通讯作者：
Smale, Dan A.
中科院分区：
文献类型：
--
作者：
Oliver, Eric C. J.;Burrows, Michael T.;Smale, Dan A.
海洋热浪（MHWs）是海洋系统中的极端气候事件，可能对生态系统产生破坏性影响，导致突然的生态变化和社会经济后果。几个著名的MHW已经引起了科学和公众的兴趣，最近的评估记录了全球和区域的频率增加。然而，对于积极主动的海洋管理来说，了解未来的模式可能如何变化至关重要。在这里，我们估计未来的变化MHWs到21世纪末，由CMIP5全球气候模式预测模拟。MHW强度和每年MHW天数的显着增加预计将加速，到世纪后期，海洋的许多部分将达到近乎永久的MHW状态。考虑的两种温室气体（GHG）排放情景（代表性浓度途径4.5和8.5）强烈影响MHW事件的预计强度、暴露于永久MHW状态的地球仪的比例以及最极端MHW事件的发生。与没有人为强迫的自然世界模拟的比较表明，这些趋势出现在21世纪上半叶的自然变率的预期范围内。这种差异意味着一定程度的“人为出现”，与自然MHW条件，以前塑造了几个世纪甚至几千年的海洋生态系统的偏离。根据这些预测，我们预计，整个世纪，海洋生态系统将受到广泛、重大和持续的影响。
Marine heatwaves (MHWs) are extreme climatic events in oceanic systems that can have devastating impacts on ecosystems, causing abrupt ecological changes and socioeconomic consequences. Several prominent MHWs have attracted scientific and public interest, and recent assessments have documented global and regional increases in their frequency. However, for proactive marine management, it is critical to understand how patterns might change in the future. Here, we estimate future changes in MHWs to the end of the 21st century, as simulated by the CMIP5 global climate model projections. Significant increases in MHW intensity and count of annual MHW days are projected to accelerate, with many parts of the ocean reaching a near-permanent MHW state by the late 21st century. The two greenhouse gas (GHG) emission scenarios considered (Representative Concentration Pathway 4.5 and 8.5) strongly affect the projected intensity of MHW events, the proportion of the globe exposed to permanent MHW states, and the occurrence of the most extreme MHW events. Comparison with simulations of a natural world, without anthropogenic forcing, indicate that these trends have emerged from the expected range of natural variability within the first half of the 21st century. This discrepancy implies a degree of "anthropogenic emergence," with a departure from the natural MHW conditions that have previously shaped marine ecosystems for centuries or even millennia. Based on these projections we expect impacts on marine ecosystems to be widespread, significant and persistent through the 21st century.