< p >总的来说,任何个人代理不是一个可靠指标。多个代理的组合,提供了一个清晰的图像。< / p > < p >例如,树木的年轮增长与温度有关。然而,这并不是没有它的异常:< / p > < blockquote > < p >…从20世纪中叶树环增长低于预期的温度记录……([源]< / p > < /引用> < p > (< a href = " http://www.climatedata.info/Proxy/Proxy/treerings_introduction.html " > http://www.climatedata.info/Proxy/Proxy/treerings_introduction.html < / >)) < / p > < p >如果我们只看只好,对他们我们不可能信任可靠来源,因为他们已经知道的问题。< / p > < p >我们也可以使用珊瑚作为过去的气候指标。然而,这也是有些怀疑:< / p > < blockquote > < p >然而,长(multi-centure)记录很少,可能影响non-climatic影响尚未建立自信。源< a href = " http://www.meteo.psu.edu/holocene/public_html/shared/articles/MannPersp2002.pdf " > < / > < / p > < /引用> < p >冰核也不能免于怀疑:< / p > < blockquote > < p >一个不争的专门的解释氧同位素的大气温度变化,此外,仍然是难以捉摸的,精确的年度约会是很困难的。< / p > < /引用> < p >不过,如果我们能结合这三个显示以及其他指标(花粉、地球孔等),我们可以增加我们的理解的可靠性。例如,如果大多数指标显示冷的一年,我们可以更多的可靠性说那是一个寒冷的一年。< / p > < p >结合这些代理一起帮助我们获得一个清晰的过去的环境。< / p > < p > < >强整体可靠性< /强> < / p > < p >然而,说完这些,与多代理方法的不确定性并不小。< / p > < p >在地球科学中的数学研讨会,布莱克麦柯肖恩提出了一种新的算法估算古气候。 This algorithm provided a more reliable estimate by increasing the uncertainty of the predictions. That's an important point that I will restate: Through his talk, he showed that his method was more reliable because it was less certain.
Even that wide uncertainty level, he questioned:
Indeed, this should make us increase our level of uncertainty (indeed perhaps our wide intervals are in fact optimistically too narrow)!
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In the end, we can look at proxies for guidelines and trends, but they cannot be used for reliable readings.