Wetlands store carbon by burying sediments loaded with organic, carbon-rich matter underwater. When tidal wetlands flood from tides or sea-level rise, sediment accumulates above the bedrock floor. The higher the waters rise, the more space for sediment to build up. Credit: University of Wollongong

Coastal wetlands capture more carbon as seas rise

As sea levels rise, coastal wetlands could play a key role in mitigating the effects of greenhouse gas emissions by capturing and storing large volumes of atmospheric carbon dioxide (CO2), research published in Nature has found.


New research shows tidal marshes could help mitigate the impact of climate change

Coastal wetlands (mangrove and saltmarsh) capture and store more CO2 per unit area than any other natural system. This is due to the high rate at which they generate biomass, and the saline, oxygen-depleted soils in which they grow, which are ideal for the burial and long-term storage of organic carbon.

The new research shows that these wetlands, termed "blue carbon" ecosystems because of their connection to the sea, become even more effective at sequestering CO2 as sea levels rise.

The research paper is the result of collaboration between researchers from the University of Wollongong (UOW), Australia; Macquarie University, Australia; Smithsonian Environmental Research Center, USA; Nelson Mandela University, South Africa; Yunnan University, China; and the Australian Nuclear Science and Technology Organisation.

Lead author Associate Professor Kerrylee Rogers, from UOW's School of Earth, Atmospheric and Life Sciences, said the research team analysed carbon stored in more than 300 saltmarshes across six continents, collecting data from the past 6000 years.