The inland water CO2 emissions – coming from water bodies such as lakes, rivers, ponds, and streams – are undercounted by about 13% and are expected to continue to rise due to global warming and land use changes. Those findings were presented in a study conducted by Oak Ridge National Laboratory (ORNL) scientists.
The research, published in Global Change Biology, said that inland waters send 4.4 billion tons of CO2 to ambient air per year. The scientists reached that number following new modeling of previous estimates and better sampling and data from different types of bodies of water, including dried and shrinking ones.
Earth system modelers increasingly focus on the complex processes that affect inland waters. A Yale study published in 2019 discovered that there is an important relationship between storms, ecology, and topography when it comes to the release of inland water CO2 emissions into the atmosphere. A better understanding of the different factors at play would be key to making more accurate predictions about carbon cycles, especially as extreme weather events are expected to increase in upcoming years.
“About 70% to 80% of carbon entering inland waters from land doesn’t make it to the ocean; it’s processed inland first,” said Dr. Rachel Pilla, a postdoctoral research associate in the Environmental Sciences Division at ORNL. “This is a missing piece of the puzzle for Earth system models to better predict and prepare us for the future.”