By Alastair Dawson
Sea level change is something that probably everyone who does their best to keep up to date about climate change, thinks they know about and on which they will have an opinion.
However, this guide clearly shows that there are important misconceptions about the topic, and recent newspaper articles, TV and radio presentations unfortunately tend to bear little relation to reality.
In fact, before I read Introducing Sea Level Change, I thought there was very little to know about sea level change. If all the ice of Antarctica were to melt today, then sea levels go up. Don’t they? Actually, if you were to remove all the ice of the East and West Antarctic ice caps, sea levels close to Antarctica will actually go down, while in remoter seas and oceans, they will go up significantly.
Why? Because the gravitational pull of the huge quantity of ice that is currently covering the continent pulls the Southern Ocean’s water towards it. Remove it and that gravitational pull disappears, and so nearby sea levels fall.
This detail is an example of several significant factors that make the science of sea level change extremely challenging and involve many different scientific disciplines. (Glacio-isostatic rebound is another, in which large quantities of ice have depressed the rocks beneath it, only for that depression to rebound when the ice is removed.)
Many (if not most) of these are not well known. In fact, the science of sea level change has ultimately dismissed the idea of a single eustatic sea level curve for the whole world. In its place is the realisation that there is a multiplicity of geological processes influencing patterns and rates of relative sea level changes for any location.
The book covers sea level change(s) since the end of the last ice age but concludes with a consideration of the rates and patterns of sea level changes that have occurred over the last century. In particular, it demonstrates how satellite technology is currently contributing new ways of understanding present patterns of change.
Alastair Dawson is Honorary Professor of Physical Geography at the University of Dundee and has published over 100 academic papers on various aspects of sea level change research and coastal science during the last 40 years.
Introducing Sea Level Change, by Alistair Dawson, Dunedin Academic Press Ltd, Edinburgh (2019), 91 pages (paperback), ISBN: 9781780460871