What was done
The authors analyzed trends in sea level data from several tide gauges located within Tauranga Harbor, New Zealand over the period 1960-1998.

What was learned
In an examination of seasonal, interannual and decadal distributions of storm surge data, the authors report a considerable decline in the annual number of storm surge events in the latter half of the nearly four-decade-long record.  A similar trend was noted in the magnitude of storm surges; and maximum water levels, including tides, also declined over the past two decades.

Decadal variations in the data were linked to both the Inter-decadal Pacific Oscillation (IPO) and the El Niņo-Southern Oscillation (ENSO).  La Niņa events were associated with more storm surge days than El Niņo events.  Wavelet analyses of annual storm surge frequency data suggested that before 1978 the frequency "was enhanced by the IPO, and subsequently it has been attenuated."

What it means
The results of this study cast grave doubt upon the climate alarmist claim that CO2-induced global warming will lead to increases in the frequency and magnitude of storms.  During the last two decades, for example, when the climate alarmists claim the earth warmed faster than it has at any other time in the past ten thousand years, these real-world data indicate that both the frequency and magnitude of New Zealand storm surges have decreased, which is just the opposite of what they are always trying to scare us into believing.