New 'time travel' study reveals future impacts of climate change on coastal wetlands

New research from Tulane University shows that nature communications This provides a glimpse into the impacts that climate change may have on coastal wetlands more than 50 years from now.

Scientists typically have to rely on computer models to predict the long-term effects of rising sea levels. But an unforeseen set of circumstances made a real-world experiment along the U.S. Gulf Coast possible.

After Hurricanes Katrina and Rita, an extensive network of approximately 400 monitoring sites was established along the Louisiana coast. Since then, the rate of sea level rise in the region has soared to more than 10 millimeters (0.5 inches) per year, at least three times the global average. As such, the region was exposed to a type of sea level rise that he did not foresee until around 2070. Accelerated sea level rise has created a unique opportunity to determine whether wetlands can withstand that pace of coastal flooding.

“It's the dream of every field researcher who does experiments. Basically, we can travel 50 years into the future and get a peek at what's going on.” Tulane said Thorbjörn Tornqvist, Vokes Professor of Geology in the Faculty of Earth and Environmental Sciences.

Researchers used a new technique developed by European scientists to measure sea level rise off the coast using previously unavailable satellite data. The researchers then compared the rate of water level rise at each monitoring site to the rate of change in wetland elevation measured by other instruments and found that water levels were falling at nearly 90% of the sites.

“To our knowledge, this is the first time that a climate impact experiment has been conducted over such a large area, based on hundreds of stations collecting data over about 15 years,” said Dr. Guangdong Li. Ta. candidate in Earth and Environmental Sciences at Tulane University, who led the research. “This also allowed us to study the effects of climate on landscapes that have been heavily influenced by humans, rather than more resilient, pristine ecosystems.”

As Lee was studying the effects of land subsidence along the Louisiana coast, a team led by Senke Dangendorff, the David and Jane Flowery Professor in Tulane University's Department of River and Coastal Science and Engineering, was conducting unprecedented research on the Gulf Coast and Southeast. It was demonstrated that sea level rise is occurring at a rapid rate. Since 2010, U.S. coasts.

“Guandon immediately abandoned everything he was working on to take advantage of this unique opportunity,” Tornqvist said. “He sought to answer the important question of whether coastal wetlands could keep up with the rate of this sea level rise, as some previous modeling studies had suggested could be possible. ”

If current climate scenarios continue, sea level rise is expected to be approximately 7 millimeters (1/4 inch) per year by 2070. The study predicts that by then, about 75% of wetlands could be in the red, with wetland loss at a much higher rate than has already occurred over the past century.

However, researchers stress that immediate action can lead to more favorable outcomes. Achieving the goals set by the Paris Agreement and reducing carbon emissions will enable us to move to a more sustainable climate trajectory that reduces the rate of wetland loss.