May 17 (UPI) -- New research suggests dams and the reservoirs they create play a significant role in the global carbon cycle, yet are largely unaccounted for in climate models.
"Dams don't just have local environmental impacts. It's clear they play a key role in the global carbon cycle and therefore Earth's climate," Philippe Van Cappellen, a researcher at the University of Waterloo, in Canada, said in a news release. "For more accurate climate predictions, we need to better understand the impact of reservoirs."
Roughly one-fifth of the carbon being transported by rivers from land to sea is trapped in reservoirs. The man-made bodies of water can act as a sizable carbon sink, but their relationship with the environment and their impact on climate isn't well understood.
Researchers say that's a problem, especially considering the planet already hosts more than 70,000 large dams -- with many more currently under construction.
Related
Scientists at Waterloo and the Free University of Brussels, in Belgium, designed a model to measure the impact on reservoirs on the carbon cycle. Researchers looked at the influence of specific parameters like water flow and reservoir size.
"With the model used in this study, we can better quantify and predict how dams affect carbon exchanges on a global scale," said Van Cappellen, a professor of earth and environmental sciences at Waterloo.
The new findings -- detailed in the journal Nature Communications -- add to a growing body of research concerned with the environmental and ecological impacts of dams.
One recent study showed large dams impede the flow of nutrients and health water to wetlands, lakes, floodplains and other marine ecosystems downstream.
"We're essentially increasing the number of artificial lakes every time we build a dam," said lead study author Taylor Maavara, a doctoral student at Waterloo. "This changes the flow of water and the materials it carries, including nutrients and carbon."
