The Environment Institute and School of Biological Sciences, University of Adelaide, Adelaide, SA, Australia.
Australian Institute of Marine Science, PMB No. 3, Townsville, Qld, Australia.
Glob Chang Biol. 2018 Mar;24(3):1371-1381. doi: 10.1111/gcb.13932. Epub 2017 Oct 30.
The current distribution of species, environmental conditions and their interactions represent only one snapshot of a planet that is continuously changing, in part due to human influences. To distinguish human impacts from natural factors, the magnitude and pace of climate shifts, since the Last Glacial Maximum, are often used to determine whether patterns of diversity today are artefacts of past climate change. In the absence of high-temporal resolution palaeoclimate reconstructions, this is generally done by assuming that past climate change occurred at a linear pace between widely spaced (usually, ≥1,000 years) climate snapshots. We show here that this is a flawed assumption because regional climates have changed significantly across decades and centuries during glacial-interglacial cycles, likely causing rapid regional replacement of biota. We demonstrate how recent atmosphere-ocean general circulation model (AOGCM) simulations of the climate of the past 21,000 years can provide credible estimates of the details of climate change on decadal to centennial timescales, showing that these details differ radically from what might be inferred from longer timescale information. High-temporal resolution information can provide more meaningful estimates of the magnitude and pace of climate shifts, the location and timing of drivers of physiological stress, and the extent of novel climates. They also produce new opportunities to directly investigate whether short-term climate variability is more important in shaping biodiversity patterns rather than gradual changes in long-term climatic means. Together, these more accurate measures of past climate instability are likely to bring about a better understanding of the role of palaeoclimatic change and variability in shaping current macroecological patterns in many regions of the world.
目前的物种分布、环境条件及其相互作用仅代表了一个不断变化的星球的一个瞬间，部分原因是人类的影响。为了将人类的影响与自然因素区分开来，通常会利用末次冰期以来气候转变的幅度和速度来确定当今物种多样性模式是否是过去气候变化的人工产物。在缺乏高时间分辨率古气候重建的情况下，这通常是通过假设过去的气候变化是在广泛间隔（通常为≥1000 年）的气候快照之间以线性速度发生的来实现的。我们在这里表明，这是一个有缺陷的假设，因为在冰期-间冰期循环期间，区域气候在几十年和几个世纪内发生了显著变化，这可能导致生物区系的快速区域更替。我们展示了最近的大气海洋通用环流模型（AOGCM）如何模拟过去 21000 年的气候，可以对几十年到百年时间尺度的气候变化细节提供可信的估计，表明这些细节与从更长时间尺度信息推断出的情况有根本的不同。高时间分辨率信息可以提供更有意义的气候转变幅度和速度、生理压力驱动因素的位置和时间以及新气候范围的估计。它们还为直接调查短期气候变率在塑造生物多样性模式方面是否比长期气候均值的缓慢变化更为重要提供了新的机会。这些对过去气候不稳定性的更准确测量，可能会更好地理解古气候变化和变异性在塑造世界许多地区当前宏观生态格局方面的作用。
