Whether or not the variation is a predictable cycle notwithstanding, there is a substantial natural variation, and the 1960s coincided with a drop in Atlantic s

Whether or not the variation is a predictable cycle notwithstanding, there is a substantial natural variation, and the 1960s coincided with a drop in Atlantic sea temperatures of the right order of magnitude. Which suggests that natural variation could have caused the 1960s to be unusually cool relative to overall warming trends.