That is the relevant question, when you read alarmist stories about ice melt in Antarctica. On March 25th, for example, the BBC dutifully reported “Antarctic Shelf Hangs by a Thread” in a report by science correspondant Helen Briggs. Here is the tag line below the title: “A chunk of ice the size of the Isle of Man has started to break away from Antarctica in what scientists say is further evidence of a warming climate.” A few paragraphs below that another tag line, also in boldface type, reads “Unprecedented Warming.” Similar alarming snippets characterize the entire report.
What this report doesn’t make terribly clear, however, is the fact that this breakup is in the Antarctic Peninsula, a finger of land that stretches for several hundred miles into the South Atlantic. There is evidence the ocean in this region is somewhat warmer in recent years – true enough – but this fact is dwarfed by the mounting evidence the overall ice mass of Antarctica is increasing.
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Here are the comparisons – the Isle of Man is 227 miles in area – which means that if this ice shelf were a mile think (and it isn’t), it would have a volume of 227 cubic miles. Antarctica, by contrast, has an area of 5.0 million square miles.
More recently, on April 15th, the BBC ran another story entitled “Forecast for Big Sea Level Rise.” The story referenced a study by “a UK/Finnish team” – we couldn’t find the actual study online – that concluded “Sea levels could rise by up to one-and-a-half metres by the end of this century, according to a new scientific analysis… substantially more than the Intergovernmental Panel on Climate Change (IPCC) forecast in last year’s landmark assessment.”
Other news sources offered similar stories – alarming headlines with a shallow exploration of the underlying facts: Reuters “World sea levels seen rising 1.5m by 2100,” New Scientist “Sea levels ‘will rise 1.5 metres by 2100′,” The Tech Herald “Report says sea level rise worse than feared,” and so on.
Accompanying the BBC story was a photo of a young woman and her infant child standing waist deep in water. But was there any further explanation of how the study reached it’s findings? According to one of the study’s authors, Svetlana Jevrejeva from the Proudman Oceanographic Laboratory (POL), near Liverpool, UK, “…by the end of the century, we predict it will rise by between 0.8m and 1.5m,” and “The rapid rise in the coming years is associated with the rapid melting of ice sheets.”
Ok, rapid melting of ice sheets is the cause. And the data? Here is all the article offered us in that regard: “The latest satellite data indicates that the Greenland and West Antarctic ice sheets are losing mass, though the much bigger East Antarctic sheet may be gaining mass.”
If you wade through this material, what comes out is the following: If temperatures increase sufficiently in the polar regions, “melt water” on the surface of land based ice sheets may drain into fissures in the ice, undermining the stability of the ice and possibly causing it to slide into the ocean at a rate far faster than if it were to simply melt from the outside inwards. Fair enough. So is Antarctica warming up?
We contacted Dr. Roger Pielke Sr., a renowned climatologist with a nuanced position on global warming – he believes, as we do, that the role of CO2 in driving climate change is grossly overstated, and the role of land use changes is grossly understated. His online blog Climate Science is an excellent source of informed and balanced data on global climate trends. Here is the gist of his findings, filed online on April 7th in a post entitled “Recent Data on Surface Snowmelt in Antarctica:”
“In the March 25 2008 issue of EOS, there was a News item by Marco Tedesco titled “Updated 2008 Surface snowmelt Trends in Antarctica” (subscribers only). It reports the following:
Surface snowmelt in Antarctica in 2008, as derived from spaceborne passive microwave observations at 19.35 gigahertz, was 40% below the average of the period 1987–2007. The melting index (MI, a measure of where melting occurred and for how long) in 2008 was the second-smallest value in the 1987–2008 period, with 3,465,625 square kilometers times days (km2 × days) against the average value of 8,407,531 km2 × days (Figure 1a). Melt extent (ME, the extent of the area subject to melting) in 2008 set a new minimum with 297,500 square kilometers, against an average value of approximately 861,812 square kilometers.”
This evidence suggests that Antarctica, where 90% of the land based ice in the world resides, is increasing in mass. And this fact is ignored or downplayed in virtually every mainstream report available today, and indeed the mainstream press continues to infer that Antarctica is melting at an alarming rate. But on balance, the ice mass in Antarctica is not melting, it is probably getting bigger.
As Pielke wrote me earlier this week, “My views have not changed… I agree that the alarmist view being widely disseminated is not supported by the science.”