The internal levee system

A rather terrifying moment of truth emerged in the second CNN Democratic Presidential Debate last Wednesday night. Each candidate proposed their solutions to global warming until tech entrepreneur and UBI advocate Andrew Yang said loudly, “It’s too late.”

The damage from Global Warming has gone too far to reverse, he maintained, noting that the United States only produces 15 percent of carbon emissions in any case. China, India, and other emerging industrial nations are not going to quit burning fossil fuels even in America achieves zero net carbon emissions by 2040.

“We like to act as if we’re 100 percent,” he continued, “Even if we were to curb our emissions dramatically, the Earth is going to get warmer. The last four years have been the four warmest years in history. We are too late. We are 10 years too late…We need to do everything we can to start moving the climate in the right direction, but we also need to start moving our people to higher ground.”

He went on to pledge billions to that end if elected President (along with enacting his $1,000 per person per month “Freedom Dividend”.) Nevertheless, what if Andrew Yang is right?

What if it is too late to reverse global warming, and the oceans stand to rise by 4-5 feet thanks to melting ice caps? What if New Orleans is designed to become an island – or worse? Should we begin preparing coastal defenses now, rather than focusing on reducing carbon omissions? Should we be building seawalls and dams rather than enacting carbon taxes if it is realistically too late to stop global temperatures from rising by 3.66 degrees Celsius by 2100?

For South Louisiana under higher ocean tides, our best case scenario still appears dystopian. Melting ice caps would submerge Houma, Thibodeaux, Plaquemine, Calcasieu, and other coastal regions. Absent any barrier at the Chef Pass and the Rigolets, the Gulf of Mexico would inundate Lake Pontchartrain in a permanent Katrina-like manner, overtake Lake Maurepas, and create an arch of water stretching as far as Laplace. The ancient name “Isle de Orleans” would become fact, and ANY failure of the newly constructed levees or foodwalls would flood the bowl of the city forever.

Moreover, that’s our best case scenario. In the worst case, Donaldsonville transforms into beachfront property, and the only way Mardi Gras floats run down St. Charles Avenue is if they actually float.

That means, should Yang prove correct, the so-called “10,000 year protections” – permanent seawalls, dams, and ocean barriers – go from extra Category-5 hurricane protections to necessities of existence. Tragically, the debate on whether we can even save coastal communities takes on an ominous focus.

Regardless of Yang’s Cassandra-like warning, building new barriers still makes sense from a Hurricane defensive standpoint. Even if sea-levels do not rise by four feet, a floodgate structure at the Rigolets would cordon-off the Pontchartrain basin in the event of storm-surge, protecting not only New Orleans, but Mandeville and Slidell, towns which lack any levee systems currently.

A second set of concrete and earthen barriers flanking the south-marshes from Belle Chase to Algiers to Gretna to Westwego to Avondale would not only defend those West Bank cities, but would provide added protections for the more populous East Bank. If built correctly, these storm-breaks could become seawalls should the worst happen.

Constructing the long proposed “internal Levee system” for Orleans and Jefferson (which would augment the natural high grounds with internal levees to help protect various parts of the city in case of massive flooding) might also come in very handy if doomsday were to occur.

None of these answers are cheap, or they would have been in place already. A flood wall at the Chef Pass costs $3 billion; 10,000-year coastal protections spiral into the hundreds of billions. That amounts to a lot less than moving a metropolis, and if Yang’s prophecy proves true, many American metros, not just our own, must have that conversation in the next four years.

After all, with an additional four feet of oceans, absent any massive seawalls, Lower Manhattan would become SuperVenice – and Miami a coral reef.

This article originally published in the August 5, 2019 print edition of The Louisiana Weekly newspaper.