所有global warming的研究都是在人類大量排放co2以後的做的,如果拉長time scale來研究，就不是那麼一回事了。

下面引用一篇研究是從PDO指數長期研究來看,網兄如果很閒的話，可以看看。

這篇文章是在我讀海洋環境資訊研究所時我同學的論文主題相關的一篇paper.


Now a decade later, the global climate has not warmed 1° F as forecast by the IPCC but has cooled slightly until 2007-08 when global temperatures turned sharply downward. In 2008, NASA satellite imagery (Figure 6) confirmed that the Pacific Ocean had switched from the warm mode it had been in since 1977 to its cool mode, similar to that of the 1945-1977 global cooling period. The shift strongly suggests that the next several decades will be cooler, not warmer as predicted by the IPCC. 

Cite:
http://www.globalresearch.ca/global...g-is-here/10783