A new study from the University of Granada used a floating platform with eddy covariance technology to continuously measure greenhouse gases from the Cubillas reservoir in Spain over two years. The research, published in Global Change Biology, found that methane emissions spiked significantly during dry periods when water levels dropped, while carbon dioxide emissions stayed steady. Methane has a much higher short term warming potential than CO2, so this matters for climate projections. The study highlights that one off sampling misses these emission bursts, which are driven by lower water levels and sediment processes. As droughts and eutrophication increase in the Mediterranean region, reservoirs could become a larger source of methane. The authors argue for continuous monitoring to improve greenhouse gas accounting and inform water management in climate vulnerable areas.
