CLIMATE: The Fragile Gulf September 06, 2005 4:52 PM
CLIMATE CHANGE NEWS TODAY
The Fragile Gulf
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September 6, 2005
OVERVIEW & COMMENTARY by Dr. Glen Barry, ClimateArk
The mainstream media is finally picking up on the ecological elements of
the Hurricane Katrina tragedy that I examined in depth in my "Hurricane an
Unnatural Disaster, Root Causes Are Ecological" Earth Meander at:
Below is a very well done Time Magazine article that highlights many of
the issues I raised - including global warming and lost wetlands
contribution to this and future "natural disasters". Clearly there are
large parts of the Gulf Coast and New Orleans that should not be rebuilt,
but rather should be restored to natural ecosystems.
RELAYED TEXT STARTS HERE:
Title: The Fragile Gulf
Soggy soil, eroding shorelines, sudden storms, global warming.
Why the Gulf Coast is so treacherous--and why we'll never
Source: Copyright 2005, Time Magazine
Date: September 6, 2005
Byline: JEFFREY KLUGER WITH CATHY BOOTH THOMAS
If you want to get a true sense of how thoroughly Hurricane Katrina
punished the Gulf Coast last week, a flyover by helicopter or Air Force
One won't do it. The real picture doesn't resolve itself until you go 450
miles up, where a flock of Earth-observing satellites have been training
their cameras on the Gulf of Mexico and beaming what they see back home.
Researchers at Louisiana State University in Baton Rouge began studying
the first portfolio of pictures taken since the hurricane hit last week,
and what they saw was a shock. Entire barrier islands are missing. Coastal
marshes have been shredded. A Native American encampment to the south of
Port Sulphur seems to have vanished. Everywhere, dark watery splotches
appear in the spots where the overloaded levees failed and burst.
"The city," says oceanographer Nan Walker, staring dourly at an image of
New Orleans, "has turned to water."
New Orleans, of course, has always been more or less waterlogged. It sits
in a bowl that averages 9 ft. below sea level, with Lake Pontchartrain
brimming to its north, the Mississippi River running to its south and the
Gulf of Mexico crashing at its door. Keeping a place like that dry would
be a city planner's nightmare in the best of circumstances. But New
Orleans' circumstances have never been ideal; the city was built in the
center of one of the most hurricane-prone spots in the world. "New Orleans
naturally wants to be a lake," says Timothy Kusky, professor of earth and
atmospheric sciences at St. Louis University. Apparently, the city got its
wish last week.
Which raises the inevitable question: If New Orleans is such a dangerous
place, what in the world are we doing there--or, for that matter, anywhere
else on the perilous Gulf Coast from Florida to Texas? Soggy soil, eroding
shorelines and sudden storms make the whole region an unstable mess even
without human intervention. And the more we build there, the worse we seem
to make things, clawing away the natural river routes and marshlands that
replenish the land and sucking out the oil and other subterranean
resources that hold up the surface. Now, many experts warn, with
greenhouse gases raising global temperatures, we are spawning more and
deadlier hurricanes, ones that could kill a city in a single blow--if
Katrina hasn't already done that to New Orleans, Gulfport and Biloxi.
But if the cities on the Gulf Coast have always been potential deathtraps,
they have always been gold mines too--great natural ports on a warm-water
gulf, perfectly situated to profit from the traffic moving up and down one
of the world's most important shipping lanes: the Mississippi River. The
port of South Louisiana moves more tonnage each year than any other in the
nation. Add to that the commodities the Gulf produces, including nearly
30% of the nation's oil, 20% of its natural gas and a third of its fish
and shellfish, and it is clear--as many have pointed out since last
week--that even if New Orleans were completely leveled, we would have to
build something in its place.
What complicates the story of the destruction--and makes the loss of life
so tragic--is our role in the disaster. If it's true that human activity
had a lot to do with making the region vulnerable to a hit by a hurricane
like Katrina, it's also true that we knew all along the kind of
environmental damage we have been doing to the Gulf. Now that we're paying
the price for our recklessness, what are we going to do about it?
It was always evident that the Gulf of Mexico was a sweet spot for
cyclones, but it took modern meteorology to explain just why. You need a
lot of things to get a hurricane going, most important among them an
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September 06, 2005 4:53 PM
existing storm with a bit of spin to it wedged between warm ocean water
and a colder band of air above it. Locate all that at least 300 miles
north or south of the equator--where the rotation of the Earth's slightly
narrower circumference exacerbates the spin of the storm--and you have
everything you need to sustain a hurricane. The Gulf has all those
ingredients, and its cities and towns repeatedly suffer for it.
To survive such storms, early residents quickly learned that they would
have to build carefully, particularly in low-lying New Orleans. Eighteenth
century settlers established the famed French Quarter on some of the
highest ground they could find, one of the reasons it remained relatively
dry last week. As the Gulf, the lake and the river periodically
overflowed, the growing city retreated behind an ever expanding web of
soil, concrete and metal levees. Today there are 350 miles of those
barricades snaking through the city and 22 massive pumping stations that
are supposed to kick into action whenever the water sloshes over the
walls. Having constructed that elaborate system, New Orleans was not
inclined to abandon it. "The city built the levees to protect itself,"
says Craig Colten, L.S.U. geographer and author of the book An Unnatural
Metropolis. "Now there's a huge investment in drainage."
Geology has only made things worse. Gulf land is squishy stuff, made
mostly of silt deposited by eons of free-flowing rivers and periodic
floods. When the high water recedes, the sedimentary layer remains,
growing heavier and heavier and ultimately subsiding under its own weight.
The only way to keep the land from sinking altogether is to let the soil
replenish itself with each flood. Human beings have done just the
opposite, walling off New Orleans and re-engineering the Mississippi River
to flow around the growing metropolis, effectively choking off the silt
In addition to allowing the unreplenished coastal marshlands to sink, that
tampering eventually kills the wetlands that do survive, as salt water
intrudes deeper and deeper inland, killing vegetation that helps hold the
soil together. The elimination of natural flooding also causes barrier
islands, which line the Gulf and protect the coast, to shrink. The
Mississippi in its naturally flowing state spilled silt into an intricate
delta, spreading sediment east and west and fortifying the islands. Walled
and dredged all the way to the Gulf, the river now dumps that silt right
over the edge of the continental shelf. Geologists report that the
Chandeleur Islands--a healthy necklace of sandy barriers about 70 miles
from New Orleans--appeared to have been wiped out by Katrina, leaving one
more stretch of the city's coast dangerously exposed.
The Gulf's busy oil-and-gas industry doesn't help matters. Extracting
those resources below the Gulf floor is like sticking a straw into the
ground and sucking out all the liquid: ultimately you pull up the very
material that's holding up the surrounding terrain. One study found that
the greatest loss of Gulf wetlands coincided with the greatest extraction
of oil and gas in the 1970s and '80s. Houston is thought to be sinking for
much the same reason.
In Louisiana, the shrinkage is most dramatic. The state has lost 1 million
acres of coast--11/2 times the area of Rhode Island--since 1930, nearly
half of that vanished land lying between New Orleans and the Gulf. The
city proper is estimated to be sinking 3 ft. per century. And while the
whole world is struggling with rising sea levels, New Orleans and its
environs hurt more than most. The State of Louisiana is estimated to be
losing land at the alarming rate of about two acres every hour.
The forces that have caused the coast to subside are pretty well
understood. What's far less clear is the possible role of global warming.
That rising temperatures heat the ocean and melt ice caps is undisputed.
Most climate models also predict that turning up the worldwide thermometer
will lead to more extreme weather patterns--hotter hots, colder colds,
harder rains. Hurricanes would seem to be especially sensitive to climate
changes, since warm ocean waters are the fuel that drives the storms.
But while that is an easy argument to make, it's a hard one to prove.
There were a record 33 hurricanes in the Atlantic between 1995 and 1999,
and that doesn't take into account blockbusters like Katrina or 1992's
Andrew. But the period from 1991 to 1994 was one of the quietest in
history. And while the Pacific has seen an increase in hurricanes and
typhoons in recent years, the southwestern Indian Ocean has remained
stable and the northern Indian Ocean has actually seen a drop. Around the
world, all that amounts to a statistical wash. "It's an unresolved issue,"
says atmospheric scientist Kerry Emanuel of the Massachusetts Institute of
Technology, "but we do not see any increase at all in the frequency of
Emanuel and others believe that even if greenhouse heating does not spawn
more hurricanes, it may make the ones that do occur more powerful. In an
extensive study published this summer in the journal Nature, Emanuel
surveyed roughly 4,500 storms brewed in the North Atlantic and western
north Pacific since the middle of the 20th century. He found that the
average power of the storms increased 50% in those 50 years. It's a change
that, he has little doubt, is linked to global warming. A slightly weaker
Katrina may have made all the difference to New O
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