Expert about Faces on Global Warming

Posted by Joshua S. Hill

April 14, 2008

Continued from the shortened article at PlanetSave.com

Kerry Emanuel is an American professor of meteorology currently working at the Massachusetts Institute of Technology in Boston, and in 2006 was named one of Time’s 100 Influential People of that year. Much of his fame has come from being among the first to link global warming to an apparent increase in hurricane intensity.

Just three weeks before Hurricane Katrina’s landfall, Emanuel published a paper in the journal Nature, which concluded that a key measurement of the power dissipated by a storm during its lifetime, had seen a dramatic increase since the mid-1970’s. In other words, hurricane’s had grown in intensity over that time.

He continued by arguing that in the future, hurricane’s that mirrored the intensity of Katrina and the like would become more commonplace, rather than the occasional fluke.

However, this past week Emanuel has now unveiled a new and novel technique for predicting future hurricane activity. His new work suggests that, even in a world where the temperature is rising, hurricane frequency and intensity may not rise to any significant degree in the next two centuries.

Appearing in the March issue of Bulletin of the American Meteorological Society, his work is groundbreaking to say the least, but even more because of who he is. Emanuel has been a highly visible leader in his field, and a proponent of the link between global warming and stronger hurricanes. That his views have changed due to his own research is staggering, and could very well have a large influence over other scientists.

“The results surprised me,” Emanuel said of his work.

To maintain a semblance of normality (I assume), Emanuel noted that global warming may still play a role in increasing the intensity of hurricane’s, but just what the role is, he had no idea.

In fact, for a long time – though hidden by popular opinion and reporting – there has been a lot of uncertainty about hurricanes. Only last year a report was published in Nature that showed that warming seas may not increase hurricane intensity.

One of the co-authors of that paper, Gabriel Vecchi, a research scientist with the National Oceanic and Atmospheric Administration, said that Emanuel’s work highlighted the massive uncertainties that remain in hurricane science.

“While his results don’t rule out the possibility that global warming has contributed to the recent increase in activity in the Atlantic, they suggest that other factors — possibly in addition to global warming — are likely to have been substantial contributors to the observed increase in activity,” Vecchi said.

Much of the hype that has surrounded hurricane research has been focused on and around the two massive hurricanes that hit America in 2005. “Kerry had the good fortune, or maybe the bad fortune, to publish when the world’s attention was focused on hurricanes in 2005,” Roger Pielke Jr., who studies science and policy at the University of Colorado, said of Emanuel. “Kerry’s work was seized upon in the debate.”

This is especially true in the case of Al Gore’s An Inconvenient Truth, which in one of its publicity shots used a hurricane over a smokestack to visually link global warming with a real world effect.

The nature of the global warming debate is that the sensationalist opinion will always win out in popular circles. And whether or not it is supported, that it is heard by the masses inspires the opinion that that report is on the money.

What’s more is that much of hurricane research is limited by the fact that records only go back to the early 70’s. Before that, hurricane record is nothing but speculation and remembrance, and thus fails to provide an accurate measure of whether hurricane intensity has in fact intensified over the past century.

A second problem tends to pop up as well, due to the inability of computer models to predict individual tropical systems. Because computer models focus on the global atmospheric conditions, Emanuel had to insert bits of computer code that he called “seeds” that represented tropical systems. This allowed him to monitor which seeds would develop in to tropical storms and hurricanes.

In reality, the research has left many more answers than questions. Emanuel’s report projected activity nearly two centuries in to the future, and found an overall drop in the number of hurricanes, but the occasional rise in intensity in some regions.

One example that he pulled out was that of Atlantic hurricanes. Two of the seven model simulations that Emanuel and his co-authors ran suggested that the overall intensity of the storms in that area would decline. However five models suggested only a modest increase.

“The take-home message is that we’ve got a lot of work to do,” Emanuel said. “There’s still a lot of uncertainty in this problem. The bulk of the evidence is that hurricane power will go up, but in some places it will go down.”

In the end, what anyone actually knows is quickly going to be thrown out the window.

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