What was done
The authors analyzed four discontinuous sets of high-water data from the Liverpool waterfront that span the period 1768-1999, looking for changes in annual maximum high water (tide plus surge), surge at annual maximum high water (surge component of annual maximum high water), and annual maximum surge-at-high-water.

What was learned
There were no significant trends in the first two parameters over the period of study.  However, the annual maximum surge-at-high-water declined at a rate of 0.11 ± 0.04 meters per century.

What it means
The results of this study run counter to two frequent GCM predictions: (1) that CO2-induced global warming should be causing an increase in sea level, and (2) that CO2-induced global warming should be increasing the frequency and/or severity of extreme weather events such as storms.  Contrary to these predictions, real-world data from Liverpool indicate a stable maximum sea level height since 1768.  Furthermore, the observed decline in the annual maximum surge-at-high-water over the past 232 years suggests that winds that are responsible for producing high storm surges were much stronger and/or more common during the early part of the record (Little Ice Age) than the latter part (Modern Warm Period).