Forecasting the Future of the Gulf Coast as Sea Level Rises

Sea-level rise is often measured as a single, steady number. A few millimeters each year, measured against a global average. But along the Gulf Coast, reality is far more complicated. While the water rises, the land moves and the climate shifts. Communities along the shoreline need to know how to adapt and prepare for the future. 

The Gulf Research Program (GRP), created by the National Academies of Sciences, Engineering and Medicine, recently announced its 2025 funding recipients, with two of four funded projects involving Texas A&M University faculty.  
 
The GRP is an independent, science-based program founded in 2013 as part of legal settlements with the companies involved in the 2010 Deepwater Horizon disaster to support science on coastal resilience and planning. It involves collaborative teams comprised of experts from several universities. 

The program shares the findings of its researchers with coastal leaders and stakeholders to inform future planning and support timely, real-world impact.  

“The Gulf Research Program of the National Academies of Sciences, Engineering and Medicine differs from other funding agencies in that it places a strong emphasis on outreach to Gulf communities,” Chang said. “It encourages stakeholders, such as local governments, to use the research, and stakeholders participate by giving us advice on what they need to plan.” 

The first project, titled “Shifting Land, Rising Seas: Forecasting How Human and Climate Drivers Shape Gulf Coast Sea-Level Futures,” is led by Dr. Andrew Hoffman from Rice University, in collaboration with Dr. Roger Creel of Texas A&M University.   

A key focus of “Shifting Lands Rising Seas” is vertical land motion and how it can be incorporated into Gulf Coast sea-level projections. Vertical land motion refers to the upward or downward movement of the Earth relative to sea level, which can be influenced by tectonics, glacial activity, sediment deposition and human activities such as groundwater withdrawal or oil extraction. The team expects to complete its research in 2030. 

According to Hoffman, most of the land on the Gulf Coast is sinking at the same time as the sea level is rising. 

“Gulf cities are subsiding where groundwater, oil and gas have been pumped out of the ground,” Hoffman said. “The sinking due to local processes, some of which we can control, can be the same or greater in magnitude than sea-level rise caused by ice-sheet and glacier melt, ocean warming and ocean circulation. Our project aims to produce more accurate, regional estimates of subsidence and projections of regional sea-level rise and connect these forecasts to tools that planners, emergency managers, and communities can use to understand hazards associated with vertical land motion and sea level rise.” 

A second project, titled “Gulf Sea-Level Rise: Harnessing GlObal and Regional High-Resolution Models to Enhance Projections (SHORE),” is led by Dr. Ping Chang, a Distinguished Professor at Texas A&M University.  

The SHORE project, which began in 2021, incorporates previous research conducted at Texas A&M by Chang, who leads efforts to use high-resolution Earth system models to improve weather and climate simulations and predictions. During phase one of SHORE, which was selected for funding in 2022, researchers conducted simulations to investigate sea-level rise along the Gulf Coast.  

The new 2025 funding is allocated to phase two, which will extend the teams' efforts by completing a large ensemble of simulations spanning the full range of future greenhouse gas emission scenarios. The team also plans to take global climate models and focus them only on the Gulf Coast to better simulate extreme sea-level events and coastal inundation, making more accurate and area-specific predictions. This project is expected to be completed in 2030. 

Experts agree that sea levels will continue to rise through the next century, directly affecting coastal communities. This reality inspired Creel to pursue his work in geology and geophysics.  

“I wanted to get into this field because it has relevance to people’s lives right now,” Creel said. “Sea level is a discipline in which that argument is quite easy to make because there are millions of people who live along coastlines. 

According to Creel, vertical land motion is not fully accounted for in global sea-level models. 

“In my lab, we focus on glaciers and sediment distribution,” Creel said. “We are focusing on how regional processes in the past affect the present and future. The sediment deposition from the Mississippi River has a significant impact on sea-level change, but there is a knowledge gap on how that propagates into the future. We are also working to address the assumption that vertical land motion driven by human activity is linear, which is something international assessments have not yet tackled.” 

The focus on the nonlinear progression of vertical land motion makes “Shifting Lands, Rising Seas” the first project to address this statistical oversight. 

“Our data show that subsidence rates change over time, accelerating or slowing depending on changes in the hydroclimate, and how much water and oil is being extracted from the ground,” Hoffman said. “We are building the first time-varying, scenario-dependent subsidence projections directly into our sea-level projection framework. We are also combining all the physical science with detailed population movement data. These include 20 years of address-level residential mobility records that help us understand, in near real time, how communities are already responding to flooding and subsidence.” 

While Creel’s team is focused on geologic research, Chang’s team is interested in regional oceanographic inquiries. Chang says regional sea-level predictions must account for unique tidal and extreme weather occurrences in the Gulf of America. 

“Most global models do not accurately simulate regional changes in the atmosphere and ocean because it’s too local and expensive for the model to run,” Chang said. “In the Gulf of America, a major circulation feature known as the Loop Current sheds smaller-scale swirling features that move across the Gulf and influence coastal sea levels. Our team is developing global high-resolution models and downscaling regional models to better represent these processes, along with extreme events such as tropical storms and hurricanes, river discharge and coastal ocean circulation, to assess coastal flooding risks more accurately.”

As the team moves from planning to active research, it remains focused on the safety of Gulf Coast residents and the impact of sea-level rise on communities, with the goal of informing regional and national policies.  

“Folks whose houses are getting flooded are intimately familiar with and aware of the effects of sea-level rise,” Creel said. “Local communities often are ahead of policymakers in understanding that it is important to pay attention to sea level. When you start talking to people who are living there, the conversation is different than that of the state or national government.” 

Researchers have a much better understanding of how sea levels will change globally in the future, said Chang. “But obtaining accurate information on exactly how extreme sea-level events will change is much more challenging. We need this information for planning because flooding occurs primarily during extreme events. How these events will evolve in the future is critically important, yet particularly challenging to model and predict.”