The Australian takes another one of its shots against science with a
piece by Michael Asten who claims:
A recent peer-reviewed paper by Svetlana Jevrejeva from Britain’s National Oceanography Centre, Liverpool, provides a calculation of 0.6m-1.6m by 2100 using a range of climate models. However, these models also show predicted sea-level change rates of 4.2mm-5.4mm a year for the first decade of the 21st century.
I contrast these predictions with just published observations by Riccardo Riva from Delft in The Netherlands and international colleagues who use satellite technology to measure actual global sea level rise in this same decade to be in the order of 1mm a year, which happens to be about the rate of sea-level increase that has been observed during the past century. In other words, the observational data suggests the problem as modelled may be overstated by a factor of five.
Asten manages to get both papers wrong, as well as showing that he is unaware of what observations of sea level rise show. Here’s the graph from the CSIRO that you not likely to ever see in The Australian:
The title of Riva’s paper Sea-level fingerprint of continental water and ice mass change from GRACE should have told Asten that Riva was only estimating the sea level change from the change in the mass of the oceans and was not including sea level rise from thermal expansion as the oceans warm, which is the largest factor in current sea level rise.
Asten also gets Jevrejeva et al’s paper wrong. The numbers he gives (4.2mm-5.4mm per year for the first decade of the 21st century) appear nowhere in their paper. As far as I can tell, he has estimated these numbers from the graphs in their paper like the one on the right showing a hundred year projection. I tried this myself and got 3mm-6mm a year, taking into account the grey region of uncertainty. Asten has ignored the fact that Jevrejeva’s model is fitted to observed changes in sea level, so it is no surprise that it agrees with observations. They write that sea level is “in excellent agreement with available observations”.
Even after his errors were pointed out to him, Asten still got it wrong with this inadequate correction (which The Australian chose to publish as a letter, rather than correcting the article):
It has been pointed out to me that I erred in The Australian today, in that in quoting the work of Riccardo Riva I failed to consider the added sea level rise associated with expansion of the oceans as they warm. The discrepancy is smaller than I give (ie, a factor of two to 2.5 rather than 5).
And Asten has form: a year ago he had another article in The Australian which drew a stinging rebuke from the scientists whose work he misrepresented:
In his opinion piece “Climate claims fail science test”, Professor Michael Asten has misrepresented our recent research by suggesting that it casts doubt on the link between atmospheric carbon dioxide and global warming.
Our study, published in the journal Nature, is a reconstruction of atmospheric CO2 levels 33-35 million years ago when the ice cap first appeared on Antarctica. In the paper we clearly state that the results are in line with expectations from climate model simulations and theory on how the global carbon cycle ought to respond to the growth of an ice cap over very long periods of time.
Michael Asten says that climate after the ice cap grew was similar to the present day, despite higher levels of CO2. He ignores a vast amount of geological data to the contrary and our clear and fully referenced statement that the world at this time was ‘warmer than today, with no evidence for sustained continental ice caps in the northern hemisphere, and possibly West Antarctica, until much later’.
You’d think that after that, The Australian might have at least fact checked his latest piece, but support for the editorial line is more important than accuracy to The Australian.
As well as misrepresenting the science, Asten also likened his opponents to the scientists who provided support for Nazi Germany’s racist policies. See Dorothy Parker’s commentary.
Hat tip: Michael Ashley.
Update: Michael Asten responds.