Torbjörn Törnqvist from Tulane University led a team of scientists who studied Louisiana marshlands, saying that the region could be completely below sea level in the next 50 years. '1.2 million inhabitants and associated economic assets' will be disrupted by this activity fueled by global warming.
Sea levels continue to rapidly rise across 5,800 miles of land, steadily reshaping New Orleans and the rest of the Mississippi Delta (MD). Törnqvist said that 'the tipping point has already happened,' and there is no way back from the exceeded threshold, not for a couple of thousand years at least.
Coastal wetlands comprise of ecosystems which are 'prone to potentially irreversible collapse' - their natural response to external stresses such as the effects of global warming. Over recent years, Louisiana marshlands have been rapidly degrading into open water.
Globally, the average rate of sea-level rise from 2006 to 2015 was around 3.5mm/year. In the study, they tested the hypothesis if marshes in the Mississippi Delta can keep up with relative sea-level (RSL) rise of 10mm/year. If variables remain the same or worsen in the next few years, the MD cannot cope up with the rate of damage.
Damages of Global Warming
Climate change has a huge impact on wetlands as there are alterations in temperature, rainfall, sea levels, and violent storms such as hurricanes. Marshland ecosystems continue to be necessary for our response to changes in climate resulting from global warming as they store and capture carbon to reduce greenhouse gas emissions as well as moderate hazardous impacts like flooding, storm surges, and sea-level rise.
Southern Louisiana's Bayou Sauvage National Wildlife Refuge is among the locations that will be affected by this movement. It is one of the last remaining marsh areas near Lakes Pontchartrain and Borgne.The Refuge is home to 340 bird species, the American alligator, White-tailed deer, and a variety of habitats like natural bayous, lagoons, coastal forests, and freshwater marshes.
Wildlife Conservation sites aren't the only places in danger when the marshlands disappear. New Orleans would be exposed to more violent storms coming in from the Gulf of Mexico.
Törnqvist said the biggest question now is how long the state's wetlands will last, and what can be done to slow their disappearance. They noted that 'the severe degradation of MD marshes due to a variety of human impacts, including the dissection of the area by over 15,000 km of canals, has already resulted in such a loss of resilience and will make a continued shift to open water more likely.'
Our Actions Matter
Louisiana had already had plans for hurricane protection and wetland restoration. If the Coastal Master Plan is executed, building major sediment diversions can help keep wetlands above sea level. Another action is reducing global greenhouse gas emissions.
Results from the study provide evidence in determining the survival or marshes in the long-term perspective. Törnqvist highlighted the importance and impact of human actions today. 'If we take appropriate actions and we can keep that rate of sea-level rise at least a little bit in check, it's likely the wetlands are still going to drown eventually,' but not as soon as what the study predicts.