Yokoyama, Y., Lambeck, K., Deckker, P.D., Johnston, P. and Fifield, L.K. 2000. Timing of the Last Glacial Maximum from observed sea-level minima. Nature 406: 713-716.
Clark, P.U. and Mix, A.C. 2000. Ice sheets by volume. Nature 406: 689-690.
What was done
The authors analyzed four distinct sediment facies in the shallow tectonically stable Bonaparte Gulf of Australia to determine the maximum volume of land-based ice during the last ice age and the timing of the initial melting phase.
What was learned
Among a number of other things discovered and discussed by the authors, Clark and Mix (2000) point out in a companion "news and views" article that the rapid rise in sea level, caused by the melting of land-based ice that began approximately 19,000 years ago, preceded the post-glacial rise in atmospheric CO2 concentration by about 3,000 years. Then, when the CO2 finally began to rise, it had to race to make up the difference; but it still took it a couple more thousand years to catch up with the sea level rise.
What it means
As we have noted before - see our Editorial CO2 and Temperature: The Great Geophysical Waltz - in all the great global warming events of the past half million years, it is temperature that has risen first, followed by atmospheric CO2 concentration hundreds to thousands of years later. Does this mean that sea level rise causes the air's CO2 content to increase? Maybe not, but it sure doesn't suggest that the opposite is true.
Reviewed 13 September 2000