Media goofed on Antarctic data/Global warming interpretation irks scientists
San Francisco Chronicle, Feb. 4, 2002
To most people, Antarctica is just a big, dumb block of ice swarming with penguins.
But to scientists, Antarctica is one of the emerging puzzles of global warming research.
Unfortunately, global warming is such a politically charged, complex issue that scientists have had trouble conveying the complexities through the news media. They complain that coverage of two recent studies seriously misrepresented the meaning and significance of their research.
One study showed that while other continents are warming, major parts of Antarctica are cooling. The other demonstrated that the glacial "ice streams" that feed the Ross Ice Shelf in West Antarctica appear to be growing, not shrinking.
To the scientists involved, the studies suggest that the effects of global warming on Antarctica may prove harder to forecast than anticipated. But to their dismay, some newspaper editorial writers interpreted the reports as evidence that the global warming theory itself is in trouble – even though that was the furthest thing from the scientists' minds.
The screwup offers a case study in "the difficulties associated with communicating information about climate change to the public," said Benjamin Preston, an environmental biologist with the Pew Center on Global Climate Change in Arlington, Va., who wasn't involved with the studies.
One of the scientists involved in the two studies, Slawek Tulaczyk of the University of California at Santa Cruz, said the latest press misinterpretations leave him "increasingly frustrated" by sometimes-careless media coverage of the global warming issue.
Tulaczyk and Ian Joughin of the Jet Propulsion Laboratory in Pasadena reported in the Jan. 18 issue of Science that the movement of the glacial Ross ice streams appears to be slowing, allowing the ice to thicken.
In reporting these and the other findings, most science writers got the story about right. Trouble started, though, when the findings were tackled by the newspaper staff members who are typically paragons of caution: editorial writers.
A headline over an editorial in the San Diego Union-Tribune minced no words about it: "Scientific findings run counter to theory of global warming." The editorial sarcastically asked: "Oh dear. What will the doomsayers say now? How will they explain away yet two more scientific studies that clearly contradict the global warming orthodoxy?"
Some media mistakenly equated the phenomenon studied by Joughin and Tulaczyk -- a change in ice flow rates -- with ice melting rates. The mistake contributed to the erroneous belief that the studies constituted, as it were, scientific "tests" of the global warming theory.
For example, a headline in the National Post, a Canadian newspaper, declared: "Antarctic ice sheet has stopped melting, study finds."
CLIMATE TRENDS NOT RELATED
Contrary to some news reports, "the ice-sheet growth that we have documented in our study area has absolutely nothing to do with any recent climate trends," Tulaczyk declared, emphasizing those words in an e-mail to The Chronicle.
The thickening of Antarctic ice in certain regions -- especially "Ice Stream C" of the Whillans Ice Stream, adjacent to the Ross Ice Shelf -- results from unexpectedly complex internal dynamics of the ice itself.
That the ice-flow changes are unrelated to global warming is illustrated by a simple fact: Such changes were occurring long before the Industrial Revolution boosted atmospheric levels of heat-trapping gases. The area with the greatest ice thickening is on an ice stream that stopped flowing about 150 years ago.
"I keep repeating to journalists that climate science is much like economics. Both deal with complex systems," Tulaczyk observed. "Just as a single stock going up or down cannot be interpreted as a reliable indicator of economic recovery or collapse, we have to accept the occurrence of contradictory trends in the global climate."
CONVEYING INFORMATION DIFFICULT
For news media, the problem is an old one: How can writers convey interesting news about subjects like global warming to readers in a simple, easy-to-read way, without oversimplifying the complexities and obscuring the uncertainties? There's a tendency to take the "latest" results -- which may focus on just a tiny aspect of the climate change problem -- and blow them out of proportion.
In the other recent study, 13 scientists reported in the Jan. 13 issue of Nature that while other continents have warmed to record-high temperatures in recent years, most of the Antarctic surface has cooled since 1966.
Some editorial writers assumed that if Antarctica is getting cooler, then maybe the whole planet is cooling, too. "Is Another Ice-Age On the Way?" asked an editorial in the Rocky Mountain News.
Contrary to the insinuations, "global warming is real and happening right now," declared Peter T. Doran of the University of Illinois at Chicago, lead author of the Nature paper. He said the cooling trend in Antarctica appears to be a surprising, regional exception to the overall planetary warming -- that's all.
Doran emphasized: "Our paper does not change the global (temperature) average in any significant way. . . . Although we have said that more area of the continent is cooling than warming, one just has to look at the paper itself . . . to see that it is a close call.
"Our analysis suggests that about two-thirds of the main continent has been cooling in the last 35 years," Doran said. "But there is one-third of the continent that has been warming if you remove the (Antarctic) Peninsula. And with the Peninsula included, it shrinks to 58 percent cooling."
Why is Antarctica cooling at all? One speculation -- still unproven – is that the cooling may result from an unexplained change in wind patterns over Antarctica.
Normally, winds make Antarctica warmer than it would otherwise be. That's because winds force the warm upper air down toward the colder, icy ground and because winds compress and warm, like the fabled dry, warm Santa Ana winds of Southern California, as they descend the dome-shaped icy slopes of Antarctica.
In the end, these studies suggest that Antarctica's fate may prove harder to forecast than anticipated. But the temperature trends are hardly grounds for throwing out all the evidence that the planet as a whole is warming.
Observes Robert Bindschadler, an Antarctica expert at NASA's Goddard Space Flight Center in Greenbelt, Md.: "Antarctica is complicated. . . . I am dismayed that the two most recent articles have elicited what I would characterize as a gross overreaction (by news media) to the facts being reported." (He was not connected with the two studies.)
Likewise, Tulaczyk said, the press coverage of their work made it "clear to me how hard it is to bring scientific work to public attention.
"Our scientific arguments are built on an intricate net of carefully separated facts, theories, and hypotheses," he noted. "In our sentences we weigh whether to use 'is', 'may be', or 'can' as a verb." Yet such cautious scientific wording is often lost when it is translated to newsprint.
Doran bluntly advises the public: "If you want the facts, you have to go to the original scientific peer-reviewed literature, and avoid the broken-telephone effect of the popular press."
Copyright 2002 SF Chronicle