Cliff Ollier

Sea level and the carbonate sand factory of South Australia

Stable parts of the South Australia coast show that the last interglacial sea level was 2 m higher than present, but elsewhere there has been relative subsidence up to 7 m and uplift of 18 m. Estimates of changing sea level, and future projections, should state the time period involved and the tectonic background to be of any use. The coast contains ‘carbonate sand factories’ where organisms produce vast amounts of sand by fixing carbon dioxide as carbonates. Far from dissolving carbonate by acidification, carbon dioxide is an essential part of carbonate production and the continued maintenance and growth of coasts and reefs. Government policies to adapt renewable energy are unlikely to affect the system.

SEA LEVEL IN THE SOUTHWEST PACIFIC IS STABLE

Graphs of sea level for twelve locations in the southwest Pacific show stable sea level for about ten years over the region. The data are compared with results from elsewhere, all of which suggest that any rise of global sea level is negligible. The Darwin theory of coral formation, and subsidence ideas for guyots would suggest that we should see more land subsidence, and apparent sea level rise, than is actually occurring. Sea level studies have not been carried out for very long, but they can indicate major tectonic components such as isostatic rebound in Scandinavia. Attempts to manipulate the data by modelling to show alarming rates of sea level rise (associated with alleged global warming) are not supported by primary regional or global data. Even those places frequently said to be in grave danger of drowning, such as the Maldives, Tuvalu and Holland, appear to be safe.