Friday, September 09, 2005

Often on Friday the OD prints articles from other sources. Today's articles include one on Katrina and racism, one on Katrina and global warming.

Taken from the Black Commentator

UNBEARABLE CRIME ON THE MISSISSIPPI by Thulani Davis

When I woke up today, the only thought that came to mind was Reverend Jesse Jackson's indignant cry, "This is the bottom of the slave ship we are looking at."

I think Jesse actually put his finger on what happened to all of us this week. Those shots we've seen are, as he said, the bottom of the slave ships. I think that really goes to why all the rest of us watching are so traumatized. And I think it is necessary to repeat what he has said about how the people in this country have a high tolerance for viewing "black pain." Yes, while we are asking the unheard question as to why a third of New Orleans' population is poor and all black, everyone from the president on down is comfortable with these realities of our ongoing unemployment, overcrowding, homelessness, drug and alcohol addiction, neighborhood crime and despair.

Jesse's metaphor is also so apt in that you only had to listen to five minutes of reporting to know families had been separated in ways that could be irreparable – across states, even mothers from month-old babies...just evacuating babies without contact with the parents is such a nightmare, I hate even hearing about it. These are the people who were marginalized from the Internet as well; are they going to run to a computer site?

African Americans in this crisis are further having the devastating experience of watching parents suffer and die right in their faces on sidewalks where people were forced to stand, not even sit for days. And the people crowded next to them experienced the same deaths. And like our ancestors, the poor today will have no access to therapeutic treatment. This is where you just have to agree with Jesse that the people in charge have the capacity to tolerate scenes of suffering they know have been suffered by blacks for generations.

At the same time, people among the stranded have been made aware that they are being portrayed as lawless by media people who are freaking out at the idea of thousands of black people not guarded by police. That in itself is a legacy of slavery. And even as we watched, the reporters and anchors on both NBC and CNN last week both misidentified Congressman John Lewis as Congressman Elijah Cummings for hours. This is one of the staples of the era when I was young and black people first appeared on TV and no one could tell one of us from another. This is really tired, old nonsense. I found myself filing email complaints to the networks, even though I know John Lewis and many others probably told them.

Lastly, there is now what is called the Katrina Diaspora. This diaspora of people without resources puts the restoration of families and community at risk, and in the case of New Orleans' black community, probably makes that impossible. Even people who own land there are going to be in deep trouble trying to hold onto it when the real estate boondoggle gets in the courts. I'm afraid we'll be reading a lot of stupid crap about how they couldn't be found, taxes were owed, etc. as in times past throughout the South. That's why I hope Jesse gets someone to bring people like Congressman Bennie Thompson into the fold, as he is familiar with the commission that had to be set up in the Delta because people are still trying to get back land stolen in the 1930s. And the developers are probably asking for eminent domain to be declared even as I'm typing.

Will Jackson, Rev. Al, Rep. Elijah Cummings, et. al. be asking after the fact, after they've read about development plans in the papers that the black community be represented at the table of planning "the NEW New Orleans?" The cultural heritage of New Orleans, which is so singular, is in serious jeopardy. The perfect mix of forces and cultures was based in a particularly unique feature of the dispersion of Africans during slavery: a disproportionate share of the Yoruba brought here (who were a minority within the groups in Middle Passage) landed in that area. What happened after that in encounters with the French, the Caribbean and the peoples of the States, cannot be replicated. Replacing the architecture with vinyl versions of shotgun and camel back houses will not produce any Buddy Boldens, Jelly Roll Mortons or Louis Armstrongs. As a writer, I myself have used the invaluable records kept there of this unique heritage. Just as one had to worry in the several rounds of the bombing of Baghdad that not only were untold people being killed but some of the oldest treasures of human life, I feel even more concerned that no one will care that thousands have died in New Orleans, others thousands dislocated and that one of our own cultural treasures, the city of New Orleans itself, will be deprived of its cultural engine.

This is a tragedy not only for the millions there on the ground, and the national economy but for the culture at large. We are witnessing in a matter of days a dislocation one-fifth the size of Middle Passage – which took place over more than 200 years. And all those conveniences of modern social organization which would mitigate its effects for most of us – phone, internet, cars, gasoline, and family with ample housing – do not apply to this country's poor. For them, getting lost may mean not being found any more easily than in 1865 when people went on foot and in wagons following word of mouth leads to find where family members may have been sent.

It is unbearable, and unconscionable.

Thulani Davis's work as a writer includes theater, journalism, fiction, and poetry. She is the author of two novels, Maker of Saints and 1959, and Malcolm X, The Photographs (1993). She has written and narrated several television and radio documentaries. Ms. Davis is the librettist for three operas: Amistad (1997); X, The Life and Times of Malcolm X (1986) with Anthony Davis, and The E & O Line (1991), with Anne LeBaron. In 1993 she won a Grammy for album notes for Aretha Franklin, and was nominated for a Grammy for the opera X. Her play, Everybody's Ruby: Story of a Murder in Florida, premiered in 2001 at the New York Shakespeare Festival.

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Taken from the Why Files

BYE-BYE BIG EASY

Katrina was a shock, but not a surprise. Everybody worried that a hurricane might someday drown the birthplace of the blues. After Katrina, the Big Easy and the neighboring Gulf Coast have a bucketful of blues.

Thousands may be dead. Hundreds of thousands who fled the city and its low-lying environs face economic ruin and months or years of displacement, even now that the levee breaks have been fixed and the big pump-out has begun. Only a final body count will tell if Katrina will surpass the 1900 hurricane that obliterated nearby Galveston, Texas, as the deadliest natural disaster in American history.

Back in 1900, nobody was tracking hurricanes with airplanes or satellites. But satellite photos showed Katrina bearing down on the Gulf Coast, and most residents left New Orleans -- if they owned a car, that is.

The human hand?

That little discrepancy is one of several signs that, before we label Katrina a "natural disaster," we need to consider the human role. Take the whole issue of land level -- critical in New Orleans, the only major American city built below sea level.

Before the 1800s, the ever-sinking land of the Mississippi Delta was regularly replenished when floods brought sediment from the Mississippi River. No longer. The vast network of dams on the Mississippi River system holds most of that sediment in the north. And the levees that protect New Orleans, ironically, channel the sediment that does reach the South directly to the depths of the Gulf of Mexico.

Those same levees also route sediment away from the many low-lying barrier islands between New Orleans and the Gulf of Mexico. These islands temper hurricane winds and storm surges -- the ruinous mounds of hurricane-driven water that can boost sea level by 20 feet or more. The sediment shortage, compounded by development, channeling and oil pipelines, is annually destroying about 30 square miles of the barrier islands. In 50 to 80 years, New Orleans could stand naked before the Gulf.

But there's more. Following the earliest predictions of global warming, sea level is rising as glaciers melt and warming ocean water expands. If, as projected, sea level rises another 50 to 100 centimeters over the next century, storm surges will be yet more dangerous, and levees yet less effective.

So even if we ignore population growth along the coast and allegations that the federal government was lackadaisical in repairing levees, building up the barrier islands or responding to the flood, it's not clear that Katrina is entirely a "natural disaster."

Global warming is warming the oceans. Hurricanes are powered by warm seas.

Hurricanes: A global warming connection?

A series of horrific hurricanes in the Atlantic, capped by the cataclysmic Katrina, raises the question: Are hurricanes getting stronger now that global warming has started? Before we explore the relationship, let's recall some hurricane fundamentals:

Hurricanes are tropical cyclones -- rotating storms that develop in the tropics -- with winds exceeding 75 mph.

Tropical cyclones are driven by energy contained in water that evaporates from the warm sea surface.

Hurricanes don't develop when the sea-surface temperature is below about 26° C.

Hurricanes don't get much stronger than this.

Given these facts, you might think that the warming ocean, heated by the global-warming effect of greenhouse gases, would lead to more hurricanes -- and more intense hurricanes. But while the greenhouse effect has warmed the globe by about 0.5°C, hurricanes (called typhoons in the Pacific) have not grown more common. Reflecting a consensus among climatologists, Kerry Emanuel, a professor of meteorology at the Massachusetts Institute of Technology, wrote: "There is no detectable trend in the global annual frequency of tropical cyclones" in historic data that would indicate that hurricanes are growing more common on the warming Earth.

But what about hurricane intensity? When you turn the heat up under a stewpot of gumbo, the prawns, chilies and okra start sloshing around with extra vigor. If you turn up the planetary thermostat, does that happen with hurricanes?

Let's cleave the question: Have hurricanes gotten stronger now that greenhouse gases have warmed the planet? Will hurricanes get stronger as the globe warms further?

Warming and storming in the real world

Two months ago, the answer to the first question was, we expect stronger hurricanes, but the data doesn't show an increase in intensity. Then, about a month before Hurricane Katrina, Emanuel published a major study showing a significant increase in hurricane power over the past 30 years. Emanuel looked at records of wind speed and hurricane duration from 558 Atlantic hurricanes, and 1,557 Pacific hurricanes. To calculate energy production, he multiplied wind speed by itself three times, then factored in how many hours the hurricane lasted. (Wind speed cubed correlates well with hurricane damage.)

Overall, Emanuel found that by his measure, hurricane power had more than doubled in the past 30 years in the Atlantic, and almost as much in the Pacific. And when he graphed intensity against the temperature of the ocean surface, the lines were similar. "It shows a big upward trend, globally, beginning in the 1970s, that's very much in concert with tropical ocean temperature," Emanuel told us.

Tellingly, the results were similar in the tropical Atlantic, the Western Pacific and the Southern Hemisphere, he said. "What give us confidence is that, in the three major places where we have hurricanes... the trend is upward, and the same magnitude." Regarding the intensity index and sea-surface temperature, he added, "It would really be a coincidence if these happened to covary [move together] in all the places you look."

But could hurricanes get almost twice as strong from a sea-surface warming of just 0.5° Celsius? Apparently. ".5 degree doesn't sound like much," Emanuel said, "but given the actual heat content of the tropical ocean, that is an awful lot, a big change. It has produced a temperature in the tropical ocean that is warmer than in the last several thousand years."

And half a degree is a lot less than the 1.7° C rise in sea-surface temperature that several climate models have projected for late the 21st century, after atmospheric carbon-dioxide has doubled. (We'll get to the predictions about future hurricanes shortly.)

Credibility gap?

The results have been noticed in the hurricane biz. "I was initially surprised, a bit stunned, because of the magnitude of the change he was showing," says Thomas Knutson of the Geophysical Fluid Dynamics Laboratory. "A doubling of the power dissipation since the 1970s is a very large change, surprising. It's a very interesting paper." (Power dissipation is the amount of energy the hurricane extracts from the warm sea and uses to drive its winds.)

Emanuel's study merits scrutiny, says Galen McKinley, an assistant professor of atmospheric and oceanic science at University of Wisconsin-Madison. "Professor Emanuel is an expert on hurricanes, but these kind of things, when they are introduced, need some time to work through the scientific community and be generally accepted or refined." While most studies have looked at the number of hurricanes, or their Saffir-Simpson category, "This is another way of looking at it," she adds. "How do we want to define this index [of destructiveness]? There is always a debate about what is the proper index."

Experts are already prowling through the entrails of Emanuel's analysis. For one thing, Emanuel used the cube of wind speed, not wind speed itself, in his calculations, which had the effect of enhancing the impact of the worst storms. Although previous indexes of hurricane power have looked at velocity squared, Knutson observes that wind damage rises along with the cube of wind speed: "It's reasonable to look at velocity cubed."

Scratched records?

Another question concerns the bugaboo of climate history: the veracity of old records. "One thing he wrestled with was the character of the historical record," says Kevin Trenberth of the National Center for Atmospheric Research. "There's an inconsistency in the earlier years between estimates of velocity and central pressure. We know there is a very strong relationship between those in the last 20 years, where we have good data, but in the early years, the relationship is not so good, so it depends on which you believe more."

Trenberth, who directs NCAR's climate analysis section, has been thinking about the relationship between global warming and hurricanes, and suggesting a shift in focus from counting hurricanes to assessing intensity.

By evaporating more water from the sea, he says, global warming could easily raise intensity, because a higher sea-surface temperature "increases the energy available for storms." Although there is more water vapor in the atmosphere, "it's not at all clear how much goes into individual thunderstorms and how many of these are organized into hurricanes," which are vast collections of thunderstorms.

Trenberth suggests that global warming has probably already made hurricanes more severe, even if it's hard to see the signal. But Katrina has also flushed out skeptical climate experts. The Detroit News , for example, quoted William Gray, a noted hurricane expert at Colorado State University: "There is absolutely no empirical evidence. The people who have a bias in favor of the argument that humans are making the globe warmer will push any data that suggests that humans are making hurricanes worse, but it just isn't so."

But Trenberth says Gray's off base. "Sea-surface temperature is rising because of global warming, and the role of humans is clearly established in that. That increase in sea level contributes to the storm surge. The increase in sea-surface temperature is increasing water vapor, and that is increasing rainfall, which raises the potential for flooding." More water vapor also adds energy to the storms, he adds. To "unequivocally state that global warming has nothing to do with what going on in Katrina, I think they are wrong. ... To say it has no role is totally irresponsible in my view."

We tried, but failed, to reach Gray for comment.

Simmering simulation

One way to anticipate how global warming may affect future hurricanes is to simulate climate with computer models, and Tom Knutson of the Geophysical Fluid Dynamics Laboratory is a master of the method. For a 2004 study (see "Impact of CO2-Induced Warming..." in the bibliography), Knutson and Robert Tuleya used nine different climate models to project climate change over the next 70 years. Each year, they jacked up the level of carbon dioxide 1 percent compounded (as a simplified experiment to mimic the expected net effect of various emissions caused human activity over the next 70 years or so.)

As sea surface temperature and other factors that affect hurricanes changed, the researchers "made hurricanes" in the computer, and found that they indeed gained intensity as the globe warmed:

Atmospheric pressure fall: increased 14 percent at the center of the storm.
Peak winds: Up 6 percent.

Rainfall: up 18 percent within 100 kilometers of the storm center.

Storm intensity: Up one-half category on the Saffir-Simpson scale.

A half notch on the Saffir-Simpson scale, notes McKinley, "is a significant increase," since it could add several feet to the destructive storm surge. In low-lying places like New Orleans, every foot matters in the battle between levee and lake or river.

While each computer model spat out a slightly different set of conditions, they all pointed in the same direction: stronger storms. "There are many different climate models, run at high CO2 levels, that uniformly, even with different options for key processes, show an increase in hurricane intensity," says McKinley. "Predictions of increased storm intensity are more in agreement than the studies of what has happened in the recent past. Drawing a signal from the past data is harder at this point."

Yet even skeptics who don't think global warming has -- or even will -- produce stronger hurricanes say we are in a for a bad string of storms. Hurricanes in any particular region seem to wax and wane over a scale of decades. In 1995, a bad string of hurricanes started in the Atlantic that is still lambasting the Caribbean and United States. "... the shift since 1995 to an environment generally conducive to hurricane formation-warmer North Atlantic SSTs [sea-surface temperatures] and reduced vertical wind shear-is not likely to change back soon," wrote Stanley Goldenberg of the National Oceanic and Atmospheric Administration (NOAA), and colleagues. "This means that during the next 10 to 40 years or so, most of the Atlantic hurricane seasons are likely to have above average activity, with many hyperactive, some around average, and only a few below average".

We tried to talk with Goldenberg, but got intercepted by a helpful government PR minder, who directed us to Chris Landsea, another NOAA scientist, to speak about the subject. But Landsea apparently had better things to do; we never heard from him.
Here's one final thought. Hurricanes are not predictable. The Gulf Coast may not see another category 4 hurricane for 10 years. Or it could get hit again in a week. NOAA just predicted that the bulk of the storms are still ahead; the hurricane season runs until Nov. 30.

The hurricane prediction experts at Colorado State University are no more comforting: in 2005, "we will witness seasonal tropical cyclone activity at near record levels."

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