Spain’s Reservoir Reveals Methane Emission Secrets

Researchers at the University of Granada deployed a floating platform with eddy covariance technology in the Cubillas reservoir in Spain to continuously monitor greenhouse gas emissions. The team discovered that methane emissions increase significantly during droughts as lower water levels accelerate processes in sediment.

Carbon dioxide emissions remained stable, but methane levels fluctuated rapidly, changes missed by traditional sampling methods. These findings are important because reservoirs, despite covering less than 2 percent of Earth’s surface, generate 40 to 50 percent of global methane emissions.

The study, published in Global Change Biology, warns that Mediterranean reservoirs could worsen climate change under future scenarios. With nearly 90 percent of Earth’s rivers projected to have dams by mid-century, understanding and controlling these emissions is crucial for effective climate policy.