New paper finds a natural 60-year oscillation in global mean sea level

A new paper published in Geophysical Research Letters "finds that there is a significant oscillation with a period around 60-years in the majority of the tide gauges examined during the 20th Century, and that it appears in every ocean basin." The authors note "The phase of the 60-year oscillation found in the tide gauge records is such that sea level in the North Atlantic, western North Pacific, Indian Ocean, and western South Pacific has been increasing since 1985–1990", meanwhile the figure below shows the eastern North Pacific and SW Pacific phase may have bottomed around the year 2000 and may be on an up phase currently. The authors note that "the possibility [of a 60-year natural cycle] should be considered when attempting to interpret the acceleration in the rate of global and regional mean sea level rise."

Climate has also long been known to have a natural ~ 60 year cycle, along with the Pacific Decadal Oscillation [PDO] and Atlantic Multidecadal Oscillation [AMO]. A very simple climate model consisting only of the "sunspot integral" + PDO + AMO predicts 96% of the variation in global temperature [R²= .96], whereas CO2 correlates poorly with global temperature [R² = .44]. 

Is there a 60-year oscillation in global mean sea level?

We examine long tide gauge records in every ocean basin to examine whether a quasi 60-year oscillation observed in global mean sea level (GMSL) reconstructions reflects a true global oscillation, or an artifact associated with a small number of gauges. We find that there is a significant oscillation with a period around 60-years in the majority of the tide gauges examined during the 20th Century, and that it appears in every ocean basin. Averaging of tide gauges over regions shows that the phase and amplitude of the fluctuations are similar in the North Atlantic, western North Pacific, and Indian Oceans, while the signal is shifted by 10 years in the western South Pacific. The only sampled region with no apparent 60-year fluctuation is the Central/Eastern North Pacific. The phase of the 60-year oscillation found in the tide gauge records is such that sea level in the North Atlantic, western North Pacific, Indian Ocean, and western South Pacific has been increasing since 1985–1990. Although the tide gauge data are still too limited, both in time and space, to determine conclusively that there is a 60-year oscillation in GMSL, the possibility should be considered when attempting to interpret the acceleration in the rate of global and regional mean sea level rise.