How does rising atmospheric CO2 affect marine organisms?

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A Century of Sea Level Rise At New Zealand
Reference
Hannah, J.  2004.  An updated analysis of long-term sea level change in New Zealand.  Geophysical Research Letters 31: 10.1020/2003GL019166.

What was done
The author updates the earlier study of New Zealand sea level data conducted by Hannah (1990) with "a new and extended analysis."   This update includes new data covering the period 1989-2000 for the four tide-gauge stations studied plus newly obtained data for the years 1891-1893 for one of the stations.  It also treats the data in far greater detail than was done previously, progressing from hourly measurements to daily, monthly and annual means, which it then uses to determine the nature of sea level rise over the 20th century.

What was learned
Hannah reports that "the new results indicate that relative sea levels in New Zealand have been rising at an average rate of 1.6 mm/yr over the last 100 years - a figure that ? has a high level of coherency with other regional and global sea level rise determinations."  In addition, Hannah notes "there continues to be no evidence of any acceleration in relative sea levels over the record period."

What it means
The results of this carefully conducted study would appear to reflect the consequences of the non-accelerating warming of the globe over the past century or more that has brought about the gradual demise of the Little Ice Age.

References
Hannah, J.  1990.  Analysis of mean sea level data from New Zealand for the period 1899-1988.  Journal of Geophysical Research 95: 12,399-12,405.


Reviewed 31 March 2004