Baker, R.G.V. and Haworth, R.J.  2000.  Smooth or oscillating late Holocene sea-level curve?  Evidence from the palaeo-zoology of fixed biological indicators in east Australia and beyond.  Marine Geology 163: 367-386.

What was done
The authors present substantial evidence that sea-level, as measured over large portions of the Southern Hemisphere, has declined significantly since approximately 6,000 years ago.  But has the journey been smooth or oscillatory?  In attempting to answer this question, they review data, including much of their own, obtained from a number of different places in the non-glaciated, tectonically-stable regions of the Southern Hemisphere.

What was learned
For the period from 6,000 to 600 years before present, the authors demonstrate that an oscillatory mode of sea-level decline is just as likely to have occurred, in terms of "statistical justification" based on the available data, as a smooth decline.

What it means
In the words of the authors, "whether or not sea level has been subject to low-amplitude fluctuations during the late Holocene (the last ~ 6000 years) is a subject that has taken on increased importance in view of claims of possible sea-level rise associated with human-induced global warming."  If, for example, sea-level has oscillated somewhat over this period (the authors say it could have had an oscillatory amplitude of one meter or more!), it is possible the sea-level's current rising mode may be nothing more than a small portion of a natural oscillation having nothing to do with the ongoing rise in the air's CO2 content.  The authors' finding that this type of sea-level behavior is just as likely to be true as not thus casts a pall of suspicion over climate alarmist claims that the continued burning of fossil fuels will lead to the inundation of low-lying coastal areas and islands.

In light of these observations, we can draw some important conclusions about the way we should approach the future.  First, there are those who claim the continued burning of fossil fuels is nigh unto criminal, because of what they claim this course of action will ultimately mean for coastal lowlands and islands, i.e., their submergence beneath the sea.  But if they are wrong about the cause of the warming, which they believe to be the cause of the sea-level rise - and this study says there's a fifty-fifty chance they are wrong on the last point alone - the actions they would have us take could be viewed as criminal; for reducing CO2 emissions would give the inhabitants of the threatened regions a false hope of security that would ultimately be dashed by the inexorable natural rising of the sea, and at a time when it may be too late to do anything about it, especially if the global economy suffers irreparable harm from misguided energy policies that could leave it too weak to help avert the human tragedy that would likely accompany a sea-level rise of the magnitude the data of these studies suggest is possible.

This being the case, the Precautionary Principle would seem to suggest that the nations of the world should begin preparing for a sea-level rise of precisely the type the climate alarmists are ranting and raving about, not in terms of trying to avert it, as they propound - especially by incredibly disruptive measures that could well have absolutely no effect upon it - but in terms of adapting to it in some way, hopefully in advance and not in retrospect.  To do anything else, and especially something that has no impact whatsoever upon the problem, costs us dearly in terms of human and natural resources, and is actually detrimental to our ability to feed ourselves (remember that CO2 is a tremendous aerial fertilizer), is more than just illogical; it is, as they say, criminal.