Climate Science: Rising Tide - The Complexities of Sea Level
SciAm online republishes a Nature short article from yesterday:
The world’s leading climate scientists kicked up a storm in 2007, when they issued their best estimates of how quickly the oceans would swell as the globe warms. The Intergovernmental Panel on Climate Change (IPCC) projected that sea levels would rise by somewhere between 18 and 59 centimetres by the last decade of this century — an upper limit that seemed far too low to other scientists, given the pace of melting in Greenland and other changes. “We were hugely criticized for being too conservative,” says Jerry Meehl, a climate modeller at the US National Center for Atmospheric Research in Boulder, Colorado and one of the authors of the IPCC’s 2007 report.
The panel had previously projected much higher rates of sea-level rise, but its 2007 assessment admitted that it could not tackle the entire problem: the predictions did not include the possibility of rapid changes in ice cover in Greenland or the Antarctic because the authors had concluded that it was impossible to forecast such behaviour with the knowledge and models then available. Yet as early as 2009, it was clear that real sea-level rise was on pace to exceed the 2007 projections2.
I will quibble with some parts of the article, and if I had more time I would quibble more, for example the writer does a poor job explaining how gravity works on sea levels, but the over-all point is that projecting sea level rise is difficult.
Perhaps the article goes overboard, in a boffin-esque way, of describing the issues so that the lay reader, if they are so inclined, will walk away with the idea that scientists don’t really know what they are talking about.
For example, the use of “admitted” by the Nature author in referencing the sea level disclaimer in the 2007 IPCC report. This type of language use harkens back to the “Climategate” faux-scandal. When scientists use disclaimers the connotation is not the same as that in public writing and mass media writings about, say, a trial or a politician’s scandal.
I am concerned that these type of articles themselves never seem quite up to date, or lack sufficient technical details of climate change. For example, the article mentions:
Trends in local sea level can differ strongly from the global average, which is increasing by around 3.2 millimetres per year. “Some places, sea-level rise is ten times faster than the average,” says Jerry Mitrovica, a geophysicist at Harvard University in Cambridge, Massachusetts.
These kind of observations, while complex in their causes, can be illustrated rather directly, as by the Univ. of Colorado Sea Level Research Group:
Communicating science to the general public is difficult because by definition specialists (such as physical oceanographers, glaciologists, and climatologists) have expertise that the general public does not have and bridging that gap can seem too daunting.
Much press is given to sea level rise in mass media debates over climate change policy, and overall the impression I get is that this issue has little purchase in the polity of American society (as with most people around the world.) In the upcoming UNFCCC gathering in a couple of months we will hear from island nations who are very concerned about centimeters of sea level rise, but the average American is not going to be concerned about these matters, and our politics reflect that.
I remain doubtful that the for-profit media (of which Nature Publish Group is an example) will ever be able to find a way to describe accurately and comprehensively a field like climatology to an audience large enough to prove viable for the publishing company. The audience is small for highly technical writing. This is why sensationalism on climate change rules the day in media.
With the release of the next IPCC report imminent, and the next UNFCCC meeting two months away, be prepared for an onslaught of confusing and contradicting “news” articles about climate change.