January 18, 2007

Half-baked Reporting on Greenland

Filed under: Arctic, Polar

In VERY large type, the New York Times of January 16 proclaimed “The Warming of Greenland.” As has become increasingly typical of their reporting on polar climate, that’s about half of the “news that’s fit to print.”

The big story, of course, is the melting of Greenland’s ice, and threats of a major rise in sea level. After all, if the entire 630,000 cubic miles of it disappeared, the ocean would rise 23 feet.

The Times relied on an off-the-cuff estimate of ice loss, given to them by Professor Carl Boggild from the University Center at Svalbard. According to the Times, he “said Greenland could be losing more than 80 cubic miles of ice per year.” Nowhere did the Times give the amount determined by meticulous analysis of recent satellite data, which is around 25 cubic miles, published by NASA’s Scott Luthcke in Science less than two months ago.

They then quoted Richard Alley, from Penn State, who reported that “a sea-level rise of a foot or two in the coming decades is entirely possible.”

Wrong. It’s entirely impossible.

First, the current sea-level rise contributed by this amount of ice loss is probably too small to even be able to measure in coming decades. The satellite data show a reduction of 4 hundred-thousandths of Greenland’s total ice per year (while Boggild’s figure “could” be around 12 hundred-thousandths). Multiplying the satellite-based figure times 23 feet gives the annual rise in sea level of 0.01 inch per year. Averaged over three decades, that’s a third of an inch, which indeed too small to be detectable. Over a century, the rise becomes a bit more than an inch. Boggild’s guesstimate yields 3.5 inches per century.

In fact, there’s nothing very new going on in Greenland. While the Times pays great attention to ice-loss in eastern Greenland caused by current temperatures, they conveniently forgot to look at nearby temperature histories. The longest record is from Angmagssalik (Figure 1). In the summer (when Greenland’s ice melts) the temperature has averaged 43.1°F over the last ten summers. There’s one very warm summer, in 2003. The other nine years aren’t unusual at all.


Figure 1. Summer (June, July, August) average temperature at Angmagssalik, Greenland (data obtained from http://data.giss.nasa.gov/gistemp/station_data/).

From 1930 through 1960, the average was 43.7°F. In other words, it was warmer for three decades, and there was clearly no large rise in sea level. What happened between 1945 and the mid 90’s was a cooling trend, with the period 1985-95 being the coldest in the entire Angmagssalik record, which goes back to the late 19th century. Only in recent years have temperatures begun to look like those that were characteristic of the early 20th Century.

Petr Chylek, from Canada’s Dalhousie University, recently summarized Greenland’s climate history in the journal Geophysical Research Letters. He wrote that “Although the last decade of 1995-2005 was relatively warm, almost all decades within 1915 to 1965 were even warmer at both the southwestern (Godthab Nuuk) and southeastern (Ammassalik) coasts of Greenland.”

In fact, the Times could have written pretty much the exact same story in 1948, before humans had much of a hand in anything climatic. That’s when Hans Ahlmann wrote, in The Geographical Journal, a publication of the British Royal Geographic Society, that “The last decades have reduced the ice in some parts of Greenland to such an extent that the whole landscape has changed in character.” So it’s hardly something new when the Times reports, almost sixty years later, that temperatures in Greenland “are changing the very geography of coastlines.”

This isn’t the first time that the Times has been misleading concerning climate change in the high latitudes. On August 19, 2000, based upon reports from a cruise ship floating at the North Pole, they reported that “the last time scientists can be certain that the Pole was awash in water was more than 50 million years ago.” The report received top, front-page billing.

In fact, during the end of summer there’s often some open water at very high latitudes. So, on August 29, buried on page D-3, the Times admitted that it had misstated the true condition of polar ice and that an ice-free North Pole is hardly unprecedented.

Yet, in the same August 29 issue, they again misled, saying “the data scientists are now studying reveal substantial evidence that on average Arctic temperatures in winter have risen 11 degrees [F] over the past thirty years.” They claimed their statement was based upon a recent paper published in the journal Climatic Change by University of Colorado’s Mark Serreze. The average winter rise in Serreze’s paper is 2.7°F. The Times never even retracted its fourfold exaggeration of Arctic warming. Nor did they say that there was only one very small area in the Arctic where there was an 11 degree rise. The last I recall “on average Arctic temperatures” means “temperatures averaged over the entire Arctic,” not the change at one location.

So, the fact that the recent Greenland story ignored the historical record and the refereed scientific literature is nothing new. When it comes to reporting about polar climate, the Grey Lady has a consistent record of hiding parts of the truth that are inconvenient to whatever story it is trying to sell.

References:

Ahlmann, H.W., 1948. The present climate fluctuation. The Geographical Journal, 112, 165-193.

Chylek, P., et al., 2006. Greenland warming of 1920-1930 and 1995-2005. Geophysical Research Letters, 33, L11707, doi:10.1029/2006GL026510.

Lutchke, S.B., et al., 2006. Recent Greenland ice mass loss by drainage system from satellite gravity observations. Science, 314, 1286-1289.

Serreze, M.C., et al., 2000. Observational Evidence of recent change in the northern high-latitude environment. Climatic Change, 46, 159–207.




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