Sunday, June 08, 2014

More on the Significance of Temperature Trends

I expanded on my post of the other day to include first-order autocorrelation when calculating linear temperature trends.

Not surprisingly, the percentage of times the HadCRUT4 temperature series is significant, for any interval of N years, dropped significantly:


Even, for example, some 60-year linear trends aren't signficant at the 95% level -- the last being December 1877 to November 1937, when it did a U-turn about 1910. The statistical significance of that 60-year interval is 93.7%.

BTW, a useful and easy-to-read introduction to calculating trends and their uncertainities is Statistical Issues Regarding Trends by Tom Wigley.

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