Instrumental records do not go back far enough to provide us with reliable measurements of global climatic variability on timescales longer than a century.

仪器上记录的年代不够久远，因而无法可靠地提供一个世纪以前全球气候变化的测量值。

youdao

The climatic models simulated by proxy indices reflecting solar activity point out that solar variability can interpret most of temperature change before 1850.

根据多种反映太阳活动的代用指标拟合的气候模型指出，太阳活动可以解释1850年以前气温变化的大部分情况。

youdao

Zhou Liantong, Huang Ronghui. 2006. Characteristics of interdecadal variability of spring precipitation in North China and its possible cause [J]. Climatic Environ Res, 11 (4) : 441-450.

周连童，黄荣辉。2006。我国华北地区春季降水的年代际变化特征及其可能成因的探讨[j]。气候与环境研究，11 (4)：441 - 450。

youdao

The possibility of more climatic variability, though, does not, in itself, mean that greenhouse warming is not happening too.

ECONOMIST: The science of climate change