Vanderbilt researchers studying Bangladesh for harbinger of climate change impact

Jonathan Gilligan (Vanderbilt University)

Bangladesh uniquely interests U.S. climate change researchers for a pair of reasons: Its place on the globe makes it particularly vulnerable to devastating weather events, and it’s a predominantly Muslim nation that maintains a secular, pro-Western outlook.

Vanderbilt University’s Jonathan Gilligan, associate professor of earth and environmental sciences, Steven Goodbred, professor of earth and environmental sciences, Brooke Ackerly, professor of political science, and their team travel there frequently though funding from the Office of Naval Research, The National Science Foundation, and other agencies, using Bangladesh as a climate change harbinger for our own coastal regions. Particularly evident is the way land use mismanagement, similar to what happens here, has affected flooding.

“That mismanagement has contributed almost 10 times as much to relative sea level rise as global warming,” Gilligan said. “We’re looking at an island that was flooded by a tropical cyclone in 2009, a situation similar to Hurricane Katrina and New Orleans’ Lower Ninth Ward.”

The team found that, over the five decades since residents built embankments around the island for agriculture, it sunk more than a meter compared to the virgin Sundarban mangrove forest on the nearby mainland. While climate change raises sea level a couple millimeters a year, flood-control infrastructure has had a far greater impact by starving the land of sediment.

The Gulf Coast and nearby inland waterways differ from Bangladesh in many ways, but even so, many of the lessons learned overseas about how poorly considered land use and flood-control infrastructure can backfire apply, as do lessons about how attention to local communities is essential for success.

“Bangladesh and the universities we partner with there are helping us understand the details so we can make informed decisions about climate change and how we’re going to manage land in the U.S.,” Gilligan said. “Their students visit here and do research on our coast as well. We’re learning we have many similarities and many differences.”

Over the rest of this century, scientists expect sea-level rise to speed up dramatically so that, within a few decades, it may exceed the impact of sediment and land use in Bangladesh and elsewhere. As this happens, lessons learned in Bangladesh about how farmers adapt to changing environmental conditions will be even more important for maintaining social, economic and political stability in a rapidly changing world.