CORPUS CHRISTI, Texas—Hurricanes and tropical storms are known for high winds, heavy rains, and destructive flooding, but now one researcher from Texas A&M University-Corpus Christi says they also cause estuaries to “burp” carbon dioxide, contributing to the so-called “greenhouse effect.”
It’s a phenomenon discovered by Dr. Michael Wetz, Associate Professor of Marine Biology at A&M-Corpus Christi, with help from scientists from the University of North Carolina and Oregon State University, while studying Hurricane Irene, which struck the east coast in August of 2011.
“We have shown that passage of large storms like Irene can essentially cause the estuary to ‘burp’ a big slug of carbon into the atmosphere,” said Wetz. “This is concerning because carbon dioxide (CO2) levels are increasing rapidly, contributing to global climate change.”
Wetz says this storm-driven release is a previously undocumented process that contributes to CO2 buildup in the atmosphere. His study, published by the Association for the Sciences and Limnology and Oceanography, shows that a major hurricane can release as much carbon dioxide into the air, all in one burp, as would normally be stored in these systems over several years.
Carbon is stored in estuaries as organic matter in sediments and plant matter, as well as in the form of CO2 in the sediments and water. For the most part, the carbon stays trapped in the sediments and water, but when a hurricane or tropical storm passes over it churns up sediments with high CO2 content and can destroy wetland plant communities, causing the carbon dioxide to be vented into the air. And while this is a natural process that has always been in place, Wetz says there is evidence showing that it could be amplified in the future.
“The concern is that there will be changes in the frequency and/or intensity of tropical storms in the near future due to human-influenced climate change,” said Wetz. “This could alter the ability of coastal systems to store carbon.”
Wetz said the next step is to determine if this happens with smaller storms, or if it is unique to large events. What they know for sure is this process doesn’t just affect the North Carolina coast where the study was done. Hurricanes affect coastal systems worldwide in low-mid latitudes.
“We will always have hurricanes, but as a result of our influence on the atmosphere and climate system, the frequency and intensity of these storms may change,” said Wetz. “If society as a whole decides that it does not want to take a chance on this, then the only way to do anything about it is to limit the amount of greenhouse gases that nations around the world are putting into the atmosphere.”