Cohn, Timothy A.; Lins, Harry F.(2005) Nature's style: Naturally trendy, Geophys. Res. Lett., Vol. 32, No. 23, L23402 8 December 2005 And the conclusion in my own words (copyright). Costs 9$ to check if I'm cheating: The authors conclude that their findings have implications for both science and public policy. The evidence is rather convincing that the planet has warmed in the 20th century. Assuming that the current knowlegde about complexity, long-term persistence, and non-linearity of the climate system is correct, this warming could have been caused by natural dynamics. The reported trends are real but actually insignificant. This suggests that natural climatic variation may be much larger than assumed; large enough to make the observations of the past century insignificant, whether human-induced or not.