New research indicates that human activities are transforming rivers from carbon sinks into carbon sources, exacerbating climate change.
Jordan Pearson reports for CBC.
In short:
- Human activities like urbanization and agriculture are increasing carbon dioxide emissions from rivers by speeding up the decomposition of organic matter.
- A global study using cotton strips to measure decomposition rates revealed hotspots of accelerated carbon release in highly populated and agricultural areas.
- The findings highlight significant impacts on carbon cycling in rivers, emphasizing the need for careful nutrient management to mitigate environmental damage.
Key quote:
"What was shocking about our data was that even though we were selecting these relatively minimally impacted sites, we could still see hotspots where humans have really had an impact."
— Krista Capps, aquatic ecosystem ecologist at the University of Georgia
Why this matters:
Rivers play a crucial role in carbon storage, but increased decomposition rates driven by human activities threaten to turn these ecosystems into sources of carbon emissions. When rivers are healthy and ecosystems intact, they sequester carbon through vegetation and sediment processes. But when overloaded with pollutants and subject to habitat destruction, they begin releasing carbon instead. This shift contributes additional greenhouse gases to the atmosphere, further accelerating climate change.
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