By BECKY GILLETTE
Sea levels around the world are rising at greater rates that were initially predicted. What does that mean for coastal areas like the Gulf Coast?
Rising sea levels make the Gulf Coast more vulnerable to storm surge associated with hurricanes, said Dr. Torbjorn Tornqvist, chairman of the Tulane University Department of Earth and Environmental Science, who has published research on sea level rise and abrupt climate change. “Even if the hurricane climate wouldn’t change, the impact of hurricanes will become increasingly severe because higher sea levels have made the region more vulnerable.”
Tornqvist said negative impacts from sea level rise are already occurring; this is not just something expected to happen in some point in the distant future.
“Of course, it is very likely that the impacts in the future (i.e., the next couple of decades and beyond) will get worse,” Tornqvist said.
Looking back at predictions of global sea-level rise made a few decades ago, the actual rate of sea-level rise that has happened since is following the more pessimistic scenario, Tornqvist said. Globally averaged rates are currently about 3 millimeters per year.
“Along the U.S. Gulf Coast, the rate of sea-level rise in the past century has already been four times higher than during the previous millennium (i.e., before the industrial revolution),” he said.
Dr. Ed Cake, a biological oceanographer with Gulf Environmental Associates, Ocean Springs, said there could be many negative consequences to sea level rise including the loss of vegetated estuarine wetlands and all of the ecological benefits derived therefrom, including, but not limited to, native shellfish and finfish production.
He has concerns that the Mississippi coastal barrier islands could disappear due to erosion, leaving the mainland without the islands that provide protection from hurricanes. Cake said the Coast could also lose transportation corridors such as Highway 90 and Interstate 10 and the CSX Rail Line.
“There is also concern about the increased flooding vulnerability of shoreline and near shore infrastructures, including household dwellings, businesses, schools, and other public facilities,” Cake said. “We face the loss of commercial and recreational fishing resources and the revenues as the result of the conversion of our section of the ‘Fertile Fisheries Crescent’ from estuarine to open-Gulf habitats. And coastal erosion will result in the loss of shoreline and backwater communities from Waveland to Pascagoula that will require billions of dollars to replace and relocate in upland/inland sites.”
Cake said the Coast could also see the loss of Jackson County’s shipbuilding industries, including Ingalls, one of the state’s largest employers, and the Chevron Pascagoula oil refinery complex in eastern Jackson County, one of the nation’s largest refinery facilities.
Alan Sudduth, Chevron public and government affairs manager for Mississippi, said the refinery is continually investing in new equipment and technology to further its goal to operate safely and reliably.
“At our Pascagoula Refinery, this includes investments to mitigate the threat of rising water from threats like hurricanes,” Sudduth said. “A protective dike stretches more than six miles around the perimeter of the refinery and reaches 20 feet at its highest point.”
While President Donald Trump has made the decision to remove the U.S. from the Paris Agreement to limit greenhouse gas emissions contributing to a warming climate and rising sea levels, many industries—including Chevron—still support the agreement. Chevron has said that the Paris Agreement is a good initial step, but it is important to fully understand the details associated with meeting the commitments made under the accord, including potential policies and their impacts.
William “Monty” Graham, director, School of Ocean Science and Technology, University of Southern Mississippi, said the latest climate change models show the sea level is increasing faster than anticipated a couple decades ago.
“The climate models are so much better now than they were 20 years ago,” Graham said. “The models are very sophisticated and good. They are predicting an acceleration of changes like sea level rise rather than a simple straight-line increase. We may be seeing that acceleration start.”
Graham said different industries are taking steps to deal with continuing to do business as the sea levels rise.
“It is on everyone’s radar and it should be at the point,” Graham said. “But it certainly doesn’t mean we should be anti-coastal living or anti-coastal development. On the business side, I’m getting more and more tied in to how do we take what we know about the coastal environment and apply it in a way that we can optimize the opportunities for living and working on the Coast. A large portion of Mississippi’s economy relies on a healthy, vibrant Coast, what is being called the ‘Blue Economy’ linked to maritime industries. It could be as much as 50 percent of the state’s GDP is tied back to the presence of major industries on the Coast.”
Graham said the government is already taking steps in other areas to harden or armor shipyards to deal with increasing sea levels. An example is what the Navy is doing in Norfolk, Va.
“Those installations there are of such value to this nation’s security that they are already making those investments,” Graham said. “Here, enhancing our protections against storms is also helping us to prepare for down-the-road effects we are going to see more and more frequently from sea level rise.”
Graham said about a half meter of sea level rise is expected along the northern Gulf in the next 100 years.
“Probably one of the more striking effects we are going to see is in terms of flooding events,” Graham said. “If the sea level comes up a half meter, it will change how water flows off the land. We recently had a lot of rain that flooded Highway 90 in Biloxi. We’re are going to see a lot more of that kind of thing. People will have to deal with more localized flooding effects.”
The threats are considerable and real. But Graham said if humans can’t stop the march of climate change, then they must step up the march of adapting to it.
“That means making sure the environmental risks are mitigated,” Graham said. “The point is, all this is going to cost money and effort. I hope something happens with a federal infrastructure bill soon. We have to be prepared on the front end to maintain our infrastructure, and be as resilient as possible on the other side. In a developing economy, we need to keep our eye on that ball.”