Reply to Hunter and Brown Discussion of Is there any support in the long term tide gauge data to the claims that parts of Sydney will be swamped by rising sea levels?, Coastal Engineering 2012;64:161-167, Coastal Engineering 2013;75:1-3

TL;DR

This paper refutes claims of sea level acceleration at Sydney by analyzing tide gauge data, showing oscillatory patterns without evidence of current acceleration, challenging previous assertions based on selective data fitting.

Contribution

It demonstrates that long-term tide gauge data do not support sea level acceleration claims, emphasizing the importance of comprehensive analysis over selective data fitting.

Findings

Sea levels oscillate with multi-decadal and inter-annual periodicities.

No detectable acceleration in Sydney tide gauge data.

Selective data fitting may lead to incorrect conclusions about sea level trends.

Abstract

Hunter and Brown try to demonstrate in their discussion of the long term tide gauge data published in my previous paper that the sea levels are accelerating when they are not. The sea levels are mostly oscillating and certainly not positively accelerating at the present time. As shown in the graphs proposed here after, having an understanding of the oscillatory behaviour of sea levels and by using linear and parabolic fittings but not being selective in the time window to consider, the tide gauge of Sydney exhibits clear multi decadal and inter-annual periodicities but no detectable component of acceleration, similarly to the many others tide gauges of the Pacific or the rest of the world having enough quality and length. If all the long term tide gauges do not exhibit any present accelerating pattern, possibly some simulations and reconstructions may be wrong similarly to the selective assessment of the sea level rise by fitting only the few years of data useful to support the positive acceleration claim.