Correlation, filtering, systems and degrees of freedom

Guest post by Richard Saumarez Correlations are often used to relate changes in climate variables in order to establish a potential relationship between them. These variables may have been processed in some way before they are correlated, possibly by filtering them. There has been some debate, which may have shed more heat than light, about…

About these ads

The ‘correlation is not causation’ hockey stick

http://books.google.com/ngrams/graph?content=correlation+is+not+causation&year_start=1800&year_end=2008&corpus=0&smoothing=3 Mike Lorrey writes- PAY ATTENTION CLIMATE ALARMISTS: “The phrase ‘correlation does not imply causation’ goes back to 1880 (according to Google Books). However, use of the phrase took off in the 1990s and 2000s, and is becoming a quick way to short-circuit certain kinds of arguments.