I was alerted to a new paper on sea level by the author
Boretti, A., 2012: 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?, Coast. Eng., doi:10.1016/j.coastaleng.2012.01.006.
The topic is not in my area of expertise, but in order to promote the dissemination of peer-reviewed perspectives, I am posting on it. The abstract reads
“The government of Australia is supporting the statement that sea levels are rising faster than ever before as a result of increased carbon dioxide emissions. Consequent to this, low-lying coastal areas, where the majority of Australians are concentrated, have been declared at risk of sea level inundations. Maps with 0.5, 0.8 and 1.1 m sea level rise have been proposed for Sydney, the major Australian city. However, long term tide gauges, recording sea levels worldwide, as well as along the coastline of Australia, and within the bay of Sydney, do not show any sign of accelerating sea level rises at present time.”
The conclusion reads
“Consideration of the measured data recorded over a significant period of time shows that the sea levels are raising weakly without any acceleration component.
The worldwide average tide gauge result obtained considering all the data included in the Permanent Service for Mean Sea Level data base show a modest sea level rise and about zero acceleration.
The Fort Denison, Sydney tide gauge result shows the same modest sea level rise and about zero acceleration in perfect agreement with the worldwide result.
The Fremantle tide gauge result, the only other tide gauge operational in Australia over more than a century, shows the same modest sea level rise and about zero acceleration in perfect agreement with the worldwide result and the result of Sydney.
The other tide gauges operational along the coastline of Australia over shorter time scales of 30 to 40 years on average also show the lack of any acceleration component in the rate of rise of sea levels.
The most likely rise of sea level in the bay of Sydney by 2100 is therefore more likely less than the 50 mm measured so far over the last 100 years rather than the metre predicted by some models.”
I recommend, if you are interested, to contact the author for the full paper which has a set of quite informative figures.