- #1
Andre
- 4,311
- 74
At last, what we have been waiting for:
http://www.agu.org/pubs/crossref/2005/2005GL024476.shtml
And telling it's conclusion in my own words so not to infringe 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.
http://www.agu.org/pubs/crossref/2005/2005GL024476.shtml
Abstract
Hydroclimatological time series often exhibit trends. While trend magnitude can be determined with little ambiguity, the corresponding statistical significance, sometimes cited to bolster scientific and political argument, is less certain because significance depends critically on the null hypothesis which in turn reflects subjective notions about what one expects to see. We consider statistical trend tests of hydroclimatological data in the presence of long-term persistence (LTP).
Monte Carlo experiments employing FARIMA models indicate that trend tests which fail to consider LTP greatly overstate the statistical significance of observed trends when LTP is present. A new test is presented that avoids this problem. From a practical standpoint, however, it may be preferable to acknowledge that the concept of statistical significance is meaningless when discussing poorly understood systems.
And telling it's conclusion in my own words so not to infringe 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.