He reports a linear upward trend in temperature on page 4 but does not provide the statistics that tell you how likely it is that the trend is different than zero. I ran the actual regression numbers for two of the series, the one with the strongest trend (NASA GISS) and the one with the weakest trend (HadCRUT3). The results appear below after the text.
The bottom line is that neither of the "trends" comes even close to the normal p-value required to be considered statistically different from NO TREND. Generally p<0.05 is regarded as the threshold. His p-values, had he reported them, would have been about 0.17 (HadCRUT3) and 0.67 (NASA GISS).
This omission is really embarrassing--especially when reporting the p-values makes his "trends" meaningless. From glancing through the article, he almost certainly knows enough statistics to know that his "trends" are statistically meaningless and he almost certainly knows better than to compute a regression "trend" and not report the p-value for the regression. That he did not was, imho, almost surely intentional.
In formal terms, none of the series reported on page four of the article give any reason to reject the null hypothesis at the 95% (the standard), the 90% or even the 85% confidence level. The null hypothesis would be that there is NO trend in temperature between 1998 and 2007.
If this were a normal scientific paper, the reviewers would have required him to report that, as a result of his data, he could not reject the null hypothesis that there is NO TREND in temperature.
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For hadCrut3 Series
TEMP = a*Year + b
Coefficients:
Value Std. Error t value Pr(>|t|)
(Intercept) -7.7865 18.6444 -0.4176 0.6872
Year 0.0041 0.0093 0.4396 0.6718
Residual standard error: 0.08852 on 8 degrees of freedom
Multiple R-Squared: 0.02359
F-statistic: 0.1933 on 1 and 8 degrees of freedom, the p-value is 0.6718
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For NASA GISS Series
TEMP = a*Year + b Value Std. Error t value Pr(>|t|)
(Intercept) -39.6009 27.0090 -1.4662 0.1808
V2 0.0204 0.0135 1.5092 0.1697
Residual standard error: 0.1282 on 8 degrees of freedom
Multiple R-Squared: 0.2216
F-statistic: 2.278 on 1 and 8 degrees of freedom, the p-value is 0.1697
Do the analysis starting in 1999. Because:
"In other words, the reason that 1998 was so exceptionally warm is that a very strong El Niño interacted with the global warming trend to give an exceptional year."