Rising seas may unlock coastal carbon stores, with losses up to 90%

Lisa Lock

scientific editor

Meet our editorial team
Behind our editorial process

Robert Egan

associate editor

Meet our editorial team
Behind our editorial process
Editors' notes

This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:

fact-checked

peer-reviewed publication

trusted source

proofread

The GIST
Add as preferred source

Rising sea levels could do more than flood coastlines. Research from Missouri University of Science and Technology shows they may also trigger the release of large amounts of carbon stored in coastal ecosystems into the atmosphere.

"What's fascinating is that this process can become a self-reinforcing loop," says Suvrajit Ghosh, a geology and geophysics Ph.D. student at Missouri S&T. "Rising sea levels can trigger carbon release, and that release can further accelerate changes that lead to even more sea-level rise."

Ghosh and Dr. Jonathan Obrist-Farner, an associate professor of Earth sciences and engineering at S&T, published an article in the journal Science of the Total Environment based on the chemical analysis of approximately 9,500 years of sediment cores, or long columns of layered organic material, S&T researchers collected from Lake Izabal in Guatemala.

According to Ghosh, Lake Izabal was an ideal site for the study because it has experienced repeated interactions between freshwater and seawater over time, including past events when seawater moved through nearby waterways into the lake and surrounding wetlands.

"It's almost like opening a history book," he says. "Each layer records environmental conditions at the time it was deposited, allowing us to look back thousands of years. These layers act as a natural archive, preserving records of environmental conditions over long periods."

By analyzing the chemical composition of these layers, the researchers were able to track how carbon storage changed over time and during past flooding events. In some cases, when seawater entered the lake, its high sulfate concentration accelerated the breakdown of organic material, and up to 90% of the stored carbon was released into the atmosphere.

"Even though we're looking at thousands of years of history, these records help us understand what could happen well into the future and how we can better prepare," Ghosh says. "They show how sensitive these systems are and why it's important to anticipate changes that could one day affect coastal ecosystems, infrastructure and communities."

The research was part of a study that included co-authors from eight institutions across six countries.

Publication details

Suvrajit Ghosh et al, Vulnerability of blue carbon to sea-level rise in coastal freshwater ecosystems, Science of The Total Environment (2025). DOI: 10.1016/j.scitotenv.2025.180637

Journal information: Science of the Total Environment

Key concepts

effects of climate changecarbon fluxsea-level changewetland ecosystemscoastal ecosystemsCarbon Cycle

Provided by Missouri University of Science and Technology