Katrina serves up tough lesson
2005-09-02 12:03
Paris - Twice in eight months, Nature has given humans a brutal lesson about the cost of disrespect.
Last December 26, beachfront resorts in Thailand were swept away by a tsunami that could have been tamed if developers had not destroyed coral reefs and ripped up mangroves, a natural bulwark against killer waves.
On August 29, Hurricane Katrina swamped New Orleans, a city built below sealevel, sustained by a complex system of dams and whose buffer against storm surges, the wetlands of the Mississippi Delta, had been eroded by reckless development.
To most of the world, New Orleans had been the "Big Easy", the cradle of the blues, the home of cajun cooking, a symbol of laidback style.
Disaster just waiting to happen
But to environmental experts, the city had been a disaster just waiting to happen.
"We have always used New Orleans as the perfect example of the unsustainable city. It is a hopeless case," Klaus Jacob, senior research scientist at the Lamont-Doherty Earth Observatory at New York's Columbia University, said.
"The city started (to be built) in the French Quarter, on high ground, which is the logical place to be when you build a village.
"But what happened is that as settlement progressed, people didn't want to be periodically flooded. So a complicated system of levees (dams) was erected, with pumps and so on, and this allowed the city to develop.
"But at the same time, the delta subsided as a result of natural action and the city got lower as the water around it build up."
Warned in vain
The US Geological Survey (USGS) had warned in vain about preserving the delta wetlands, describing them as a "natural buffer". The progressive loss of this asset heightened the coast's exposure to floods and storms, especially in the light of evidence about global warming, the USGS said.
Warming water expands, thus boosting sea levels, and also increases the source of energy that feeds hurricanes, making them potentially more vicious.
New Orleans may be the most blatant example in the United States of unsustainable development, but it is certainly not the only one.
Other specialists point to coastline cities built on reclaimed wetlands in southern Florida, the most hurricane-prone part of the US, as well as LA and cities built in Nevada and Arizona, which need air-conditioning and a long supply line of water to survive.
These problems are not, of course, exclusively American.
Examples of unsustainable urban development teem on almost every continent - of cities whose poor location, sloppy building codes or ill-maintained infrastructure expose them to floods, earthquakes or water stress, or where choking pollution and sprawling shanty housing blight the life of its citizens.
But not all the news is bad.
Seb Beloe, director of research and advocacy at SustainAbility, said worries about climate change were prompting some countries, notably in Europe, to invest more in urban planning and building standards to protect their cities.
"A case in point is the Netherlands, which is very low-lying and vulnerable to sea-level rise," he said.
"Houses, for instance, are being designed so that they can actually float. They are built on pontoons, which rise up from the foundations if the area is flooded."
- AFP