No increase in global temperature variability despite changing regional patterns
No increase in global temperature variability despite changing regional patterns
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DOI：
10.1038/nature12310
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发表时间：
2013-08-15
期刊：
影响因子：
64.8
通讯作者：
Cox, Peter M.
中科院分区：
文献类型：
--
作者：
Huntingford, Chris;Jones, Philip D.;Cox, Peter M.
来自格陵兰冰芯的证据表明，在过去的一些寒冷时期，每年的温度变化可能更高（1），但人们对确定全球变暖是否正在增加目前的气候变化有相当大的兴趣（2-6）。这种兴趣是出于这样一种理解，即增加的变异性和由此产生的极端天气条件可能比改变的平均条件更难为社会所适应。然而，到目前为止，尽管有增加变异性的建议（2），但关于它是否正在发生，还有相当大的不确定性（7）。在这里，我们表明，尽管在过去的几十年里，年温度的波动确实显示出巨大的地理变化，但全球平均温度异常的时间演变标准差一直是稳定的。这些变化的一个特点是，许多低变率区域有增加的趋势，这可能有助于人们对气候波动性增加的看法。温度异常的标准化（2）产生了较大的相对整体增加的印象，但我们使用绝对值，我们认为这是一个更合适的方法，揭示了变化不大。就区域而言，北美和欧洲大部分地区最近出现了较大的逐年变化。许多气候模型预测，在温室气体浓度高的情况下，总的变率最终将减少，这可能与海冰覆盖的减少有关。我们的研究结果反驳了这样一种观点，即一个变暖的世界将自动成为一个更全面的气候变化。
Evidence from Greenland ice cores shows that year-to-year temperature variability was probably higher in some past cold periods(1), but there is considerable interest in determining whether global warming is increasing climate variability at present(2-6). This interest is motivated by an understanding that increased variability and resulting extreme weather conditions may be more difficult for society to adapt to than altered mean conditions(3). So far, however, in spite of suggestions of increased variability(2), there is considerable uncertainty as to whether it is occurring(7). Here we show that although fluctuations in annual temperature have indeed shown substantial geographical variation over the past few decades(2), the time-evolving standard deviation of globally averaged temperature anomalies has been stable. A feature of the changes has been a tendency for many regions of low variability to experience increases, which might contribute to the perception of increased climate volatility. The normalization of temperature anomalies(2) creates the impression of larger relative overall increases, but our use of absolute values, which we argue is a more appropriate approach, reveals little change. Regionally, greater year-to-year changes recently occurred in much of North America and Europe. Many climate models predict that total variability will ultimately decrease under high greenhouse gas concentrations, possibly associated with reductions in sea-ice cover. Our findings contradict the view that a warming world will automatically be one of more overall climatic variation.